Difference between revisions of "How to install Arduino Library"

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=='''Introduction'''==
 
The [http://www.example.com link title]is a single-chip, single-supply low power 8-bit [[mediawiki:Formatting CMOS]] data acquisition device with four analog inputs, one analog output and a serial I 2 C-bus interface. Three address pins A0, A1 and A2 are used for programming the hardware address, allowing the use of up to eight devices connected to the I 2 C-bus without additionalhardware.Address,controlanddatatoandfrom the device are transferred serially via the two-line bidirectional I 2 C-bus.
 
The functions of the device include analog input multiplexing, on-chip track and hold function, 8-bit analog-to-digital conversion and an 8-bit digital-to-analog conversion. The maximum conversion rate is given by the maximum speed of the I 2 C-bus.
 
 
----
 
 
The schematic diagram of the PCF8591 Module is shown as below:
 
<nowiki>
 
/*
 
MultiWiiCopter by Alexandre Dubus
 
www.multiwii.com
 
March  2013    V2.2
 
This program is free software: you can redistribute it and/or modify
 
it under the terms of the GNU General Public License as published by
 
the Free Software Foundation, either version 3 of the License, or
 
any later version. see <http://www.gnu.org/licenses/>
 
*/
 
 
#include <avr/io.h>
 
 
#include "config.h"
 
#include "def.h"
 
 
 
#include <avr/pgmspace.h>
 
#define  VERSION  220
 
 
/*********** RC alias *****************/
 
enum rc {
 
  ROLL,
 
  PITCH,
 
  YAW,
 
  THROTTLE,
 
  AUX1,
 
  AUX2,
 
  AUX3,
 
  AUX4
 
};
 
 
enum pid {
 
  PIDROLL,
 
  PIDPITCH,
 
  PIDYAW,
 
  PIDALT,
 
  PIDPOS,
 
  PIDPOSR,
 
  PIDNAVR,
 
  PIDLEVEL,
 
  PIDMAG,
 
  PIDVEL,    // not used currently
 
  PIDITEMS
 
};
 
 
const char pidnames[] PROGMEM =
 
  "ROLL;"
 
  "PITCH;"
 
  "YAW;"
 
  "ALT;"
 
  "Pos;"
 
  "PosR;"
 
  "NavR;"
 
  "LEVEL;"
 
  "MAG;"
 
  "VEL;"
 
;
 
 
enum box {
 
  BOXARM,
 
  #if ACC
 
    BOXANGLE,
 
    BOXHORIZON,
 
  #endif
 
  #if BARO && (!defined(SUPPRESS_BARO_ALTHOLD))
 
    BOXBARO,
 
  #endif
 
  #ifdef VARIOMETER
 
    BOXVARIO,
 
  #endif
 
  #if MAG
 
    BOXMAG,
 
    BOXHEADFREE,
 
    BOXHEADADJ, // acquire heading for HEADFREE mode
 
  #endif
 
  #if defined(SERVO_TILT) || defined(GIMBAL)  || defined(SERVO_MIX_TILT)
 
    BOXCAMSTAB,
 
  #endif
 
  #if defined(CAMTRIG)
 
    BOXCAMTRIG,
 
  #endif
 
  #if GPS
 
    BOXGPSHOME,
 
    BOXGPSHOLD,
 
  #endif
 
  #if defined(FIXEDWING) || defined(HELICOPTER)
 
    BOXPASSTHRU,
 
  #endif
 
  #if defined(BUZZER)
 
    BOXBEEPERON,
 
  #endif
 
  #if defined(LED_FLASHER)
 
    BOXLEDMAX, // we want maximum illumination
 
    BOXLEDLOW, // low/no lights
 
  #endif
 
  #if defined(LANDING_LIGHTS_DDR)
 
    BOXLLIGHTS, // enable landing lights at any altitude
 
  #endif
 
  #ifdef INFLIGHT_ACC_CALIBRATION
 
    BOXCALIB,
 
  #endif
 
  #ifdef GOVERNOR_P
 
    BOXGOV,
 
  #endif
 
  #ifdef OSD_SWITCH
 
    BOXOSD,
 
  #endif
 
  CHECKBOXITEMS
 
};
 
 
const char boxnames[] PROGMEM = // names for dynamic generation of config GUI
 
  "ARM;"
 
  #if ACC
 
    "ANGLE;"
 
    "HORIZON;"
 
  #endif
 
  #if BARO && (!defined(SUPPRESS_BARO_ALTHOLD))
 
    "BARO;"
 
  #endif
 
  #ifdef VARIOMETER
 
    "VARIO;"
 
  #endif
 
  #if MAG
 
    "MAG;"
 
    "HEADFREE;"
 
    "HEADADJ;" 
 
  #endif
 
  #if defined(SERVO_TILT) || defined(GIMBAL)|| defined(SERVO_MIX_TILT)
 
    "CAMSTAB;"
 
  #endif
 
  #if defined(CAMTRIG)
 
    "CAMTRIG;"
 
  #endif
 
  #if GPS
 
    "GPS HOME;"
 
    "GPS HOLD;"
 
  #endif
 
  #if defined(FIXEDWING) || defined(HELICOPTER)
 
    "PASSTHRU;"
 
  #endif
 
  #if defined(BUZZER)
 
    "BEEPER;"
 
  #endif
 
  #if defined(LED_FLASHER)
 
    "LEDMAX;"
 
    "LEDLOW;"
 
  #endif
 
  #if defined(LANDING_LIGHTS_DDR)
 
    "LLIGHTS;"
 
  #endif
 
  #ifdef INFLIGHT_ACC_CALIBRATION
 
    "CALIB;"
 
  #endif
 
  #ifdef GOVERNOR_P
 
    "GOVERNOR;"
 
  #endif
 
  #ifdef OSD_SWITCH
 
    "OSD SW;"
 
  #endif
 
;
 
 
const uint8_t boxids[] PROGMEM = {// permanent IDs associated to boxes. This way, you can rely on an ID number to identify a BOX function.
 
  0, //"ARM;"
 
  #if ACC
 
    1, //"ANGLE;"
 
    2, //"HORIZON;"
 
  #endif
 
  #if BARO && (!defined(SUPPRESS_BARO_ALTHOLD))
 
    3, //"BARO;"
 
  #endif
 
  #ifdef VARIOMETER
 
    4, //"VARIO;"
 
  #endif
 
  #if MAG
 
    5, //"MAG;"
 
    6, //"HEADFREE;"
 
    7, //"HEADADJ;" 
 
  #endif
 
  #if defined(SERVO_TILT) || defined(GIMBAL)|| defined(SERVO_MIX_TILT)
 
    8, //"CAMSTAB;"
 
  #endif
 
  #if defined(CAMTRIG)
 
    9, //"CAMTRIG;"
 
  #endif
 
  #if GPS
 
    10, //"GPS HOME;"
 
    11, //"GPS HOLD;"
 
  #endif
 
  #if defined(FIXEDWING) || defined(HELICOPTER)
 
    12, //"PASSTHRU;"
 
  #endif
 
  #if defined(BUZZER)
 
    13, //"BEEPER;"
 
  #endif
 
  #if defined(LED_FLASHER)
 
    14, //"LEDMAX;"
 
    15, //"LEDLOW;"
 
  #endif
 
  #if defined(LANDING_LIGHTS_DDR)
 
    16, //"LLIGHTS;"
 
  #endif
 
  #ifdef INFLIGHT_ACC_CALIBRATION
 
    17, //"CALIB;"
 
  #endif
 
  #ifdef GOVERNOR_P
 
    18, //"GOVERNOR;"
 
  #endif
 
  #ifdef OSD_SWITCH
 
    19, //"OSD_SWITCH;"
 
  #endif
 
};
 
 
 
static uint32_t currentTime = 0;
 
static uint16_t previousTime = 0;
 
static uint16_t cycleTime = 0;    // this is the number in micro second to achieve a full loop, it can differ a little and is taken into account in the PID loop
 
static uint16_t calibratingA = 0;  // the calibration is done in the main loop. Calibrating decreases at each cycle down to 0, then we enter in a normal mode.
 
static uint16_t calibratingB = 0;  // baro calibration = get new ground pressure value
 
static uint16_t calibratingG;
 
static uint16_t acc_1G;            // this is the 1G measured acceleration
 
static uint16_t acc_25deg;
 
static int16_t  gyroADC[3],accADC[3],accSmooth[3],magADC[3];
 
static int16_t  heading,magHold,headFreeModeHold; // [-180;+180]
 
static uint8_t  vbat;                  // battery voltage in 0.1V steps
 
static uint8_t  vbatMin = VBATNOMINAL;  // lowest battery voltage in 0.1V steps
 
static uint8_t  rcOptions[CHECKBOXITEMS];
 
static int32_t  BaroAlt,EstAlt,AltHold; // in cm
 
static int16_t  BaroPID = 0;
 
static int16_t  errorAltitudeI = 0;
 
static int16_t  vario = 0;              // variometer in cm/s
 
 
#if defined(ARMEDTIMEWARNING)
 
  static uint32_t  ArmedTimeWarningMicroSeconds = 0;
 
#endif
 
 
static int16_t  debug[4];
 
static int16_t  sonarAlt; //to think about the unit
 
 
struct flags_struct {
 
  uint8_t OK_TO_ARM :1 ;
 
  uint8_t ARMED :1 ;
 
  uint8_t I2C_INIT_DONE :1 ; // For i2c gps we have to now when i2c init is done, so we can update parameters to the i2cgps from eeprom (at startup it is done in setup())
 
  uint8_t ACC_CALIBRATED :1 ;
 
  uint8_t NUNCHUKDATA :1 ;
 
  uint8_t ANGLE_MODE :1 ;
 
  uint8_t HORIZON_MODE :1 ;
 
  uint8_t MAG_MODE :1 ;
 
  uint8_t BARO_MODE :1 ;
 
  uint8_t GPS_HOME_MODE :1 ;
 
  uint8_t GPS_HOLD_MODE :1 ;
 
  uint8_t HEADFREE_MODE :1 ;
 
  uint8_t PASSTHRU_MODE :1 ;
 
  uint8_t GPS_FIX :1 ;
 
  uint8_t GPS_FIX_HOME :1 ;
 
  uint8_t SMALL_ANGLES_25 :1 ;
 
  uint8_t CALIBRATE_MAG :1 ;
 
  uint8_t VARIO_MODE :1;
 
} f;
 
 
//for log
 
#if defined(LOG_VALUES) || defined(LCD_TELEMETRY)
 
  static uint16_t cycleTimeMax = 0;      // highest ever cycle timen
 
  static uint16_t cycleTimeMin = 65535;  // lowest ever cycle timen
 
  static uint16_t powerMax = 0;          // highest ever current;
 
  static int32_t  BAROaltMax;        // maximum value
 
#endif
 
#if defined(LOG_VALUES) || defined(LCD_TELEMETRY) || defined(ARMEDTIMEWARNING)  || defined(LOG_PERMANENT)
 
  static uint32_t armedTime = 0;
 
#endif
 
 
static int16_t  i2c_errors_count = 0;
 
static int16_t  annex650_overrun_count = 0;
 
 
// **********************
 
//Automatic ACC Offset Calibration
 
// **********************
 
#if defined(INFLIGHT_ACC_CALIBRATION)
 
  static uint16_t InflightcalibratingA = 0;
 
  static int16_t AccInflightCalibrationArmed;
 
  static uint16_t AccInflightCalibrationMeasurementDone = 0;
 
  static uint16_t AccInflightCalibrationSavetoEEProm = 0;
 
  static uint16_t AccInflightCalibrationActive = 0;
 
#endif
 
 
// **********************
 
// power meter
 
// **********************
 
#if defined(POWERMETER)
 
#define PMOTOR_SUM 8                    // index into pMeter[] for sum
 
  static uint32_t pMeter[PMOTOR_SUM + 1];  // we use [0:7] for eight motors,one extra for sum
 
  static uint8_t pMeterV;                  // dummy to satisfy the paramStruct logic in ConfigurationLoop()
 
  static uint32_t pAlarm;                  // we scale the eeprom value from [0:255] to this value we can directly compare to the sum in pMeter[6]
 
  static uint16_t powerValue = 0;          // last known current
 
#endif
 
static uint16_t intPowerMeterSum, intPowerTrigger1;
 
 
// **********************
 
// telemetry
 
// **********************
 
#if defined(LCD_TELEMETRY)
 
  static uint8_t telemetry = 0;
 
  static uint8_t telemetry_auto = 0;
 
#endif
 
#ifdef LCD_TELEMETRY_STEP
 
  static char telemetryStepSequence []  = LCD_TELEMETRY_STEP;
 
  static uint8_t telemetryStepIndex = 0;
 
#endif
 
 
// ******************
 
// rc functions
 
// ******************
 
#define MINCHECK 1100
 
#define MAXCHECK 1900
 
 
#define ROL_LO  (1<<(2*ROLL))
 
#define ROL_CE  (3<<(2*ROLL))
 
#define ROL_HI  (2<<(2*ROLL))
 
#define PIT_LO  (1<<(2*PITCH))
 
#define PIT_CE  (3<<(2*PITCH))
 
#define PIT_HI  (2<<(2*PITCH))
 
#define YAW_LO  (1<<(2*YAW))
 
#define YAW_CE  (3<<(2*YAW))
 
#define YAW_HI  (2<<(2*YAW))
 
#define THR_LO  (1<<(2*THROTTLE))
 
#define THR_CE  (3<<(2*THROTTLE))
 
#define THR_HI  (2<<(2*THROTTLE))
 
 
static int16_t failsafeEvents = 0;
 
volatile int16_t failsafeCnt = 0;
 
 
static int16_t rcData[RC_CHANS];    // interval [1000;2000]
 
static int16_t rcCommand[4];        // interval [1000;2000] for THROTTLE and [-500;+500] for ROLL/PITCH/YAW
 
static int16_t lookupPitchRollRC[6];// lookup table for expo & RC rate PITCH+ROLL
 
static int16_t lookupThrottleRC[11];// lookup table for expo & mid THROTTLE
 
static uint16_t rssi;              // range: [0;1023]
 
 
#if defined(SPEKTRUM)
 
  volatile uint8_t  spekFrameFlags;
 
  volatile uint32_t spekTimeLast;
 
#endif
 
 
#if defined(OPENLRSv2MULTI)
 
  static uint8_t pot_P,pot_I; // OpenLRS onboard potentiometers for P and I trim or other usages
 
#endif
 
 
// **************
 
// gyro+acc IMU
 
// **************
 
static int16_t gyroData[3] = {0,0,0};
 
static int16_t gyroZero[3] = {0,0,0};
 
static int16_t angle[2]    = {0,0};  // absolute angle inclination in multiple of 0.1 degree    180 deg = 1800
 
 
// *************************
 
// motor and servo functions
 
// *************************
 
static int16_t axisPID[3];
 
static int16_t motor[NUMBER_MOTOR];
 
#if defined(SERVO)
 
  static int16_t servo[8] = {1500,1500,1500,1500,1500,1500,1500,1500};
 
#endif
 
 
// ************************
 
// EEPROM Layout definition
 
// ************************
 
static uint8_t dynP8[3], dynD8[3];
 
 
static struct {
 
  uint8_t currentSet;
 
  int16_t accZero[3];
 
  int16_t magZero[3];
 
  uint8_t checksum;      // MUST BE ON LAST POSITION OF STRUCTURE !
 
} global_conf;
 
 
 
static struct {
 
  uint8_t checkNewConf;
 
  uint8_t P8[PIDITEMS], I8[PIDITEMS], D8[PIDITEMS];
 
  uint8_t rcRate8;
 
  uint8_t rcExpo8;
 
  uint8_t rollPitchRate;
 
  uint8_t yawRate;
 
  uint8_t dynThrPID;
 
  uint8_t thrMid8;
 
  uint8_t thrExpo8;
 
  int16_t angleTrim[2];
 
  uint16_t activate[CHECKBOXITEMS];
 
  uint8_t powerTrigger1;
 
  #ifdef FLYING_WING
 
    uint16_t wing_left_mid;
 
    uint16_t wing_right_mid;
 
  #endif
 
  #ifdef TRI
 
    uint16_t tri_yaw_middle;
 
  #endif
 
  #if defined HELICOPTER || defined(AIRPLANE)|| defined(SINGLECOPTER)|| defined(DUALCOPTER)
 
    int16_t servoTrim[8];
 
  #endif
 
  #if defined(GYRO_SMOOTHING)
 
    uint8_t Smoothing[3];
 
  #endif
 
  #if defined (FAILSAFE)
 
    int16_t failsafe_throttle;
 
  #endif
 
  #ifdef VBAT
 
    uint8_t vbatscale;
 
    uint8_t vbatlevel_warn1;
 
    uint8_t vbatlevel_warn2;
 
    uint8_t vbatlevel_crit;
 
    uint8_t no_vbat;
 
  #endif
 
  #ifdef POWERMETER
 
    uint16_t psensornull;
 
    uint16_t pleveldivsoft;
 
    uint16_t pleveldiv;
 
    uint8_t pint2ma;
 
  #endif
 
  #ifdef CYCLETIME_FIXATED
 
    uint16_t cycletime_fixated;
 
  #endif
 
  #ifdef MMGYRO
 
    uint8_t mmgyro;
 
  #endif
 
  #ifdef ARMEDTIMEWARNING
 
    uint16_t armedtimewarning;
 
  #endif
 
  int16_t minthrottle;
 
  #ifdef GOVERNOR_P
 
  int16_t governorP;
 
  int16_t governorD;
 
  int8_t  governorR;
 
  #endif
 
  uint8_t  checksum;      // MUST BE ON LAST POSITION OF CONF STRUCTURE !
 
} conf;
 
 
#ifdef LOG_PERMANENT
 
static struct {
 
  uint16_t arm;          // #arm events
 
  uint16_t disarm;        // #disarm events
 
  uint16_t start;        // #powercycle/reset/initialize events
 
  uint32_t armed_time ;  // copy of armedTime @ disarm
 
  uint32_t lifetime;      // sum (armed) lifetime in seconds
 
  uint16_t failsafe;      // #failsafe state @ disarm
 
  uint16_t i2c;          // #i2c errs state @ disarm
 
  uint8_t  running;      // toggle on arm & disarm to monitor for clean shutdown vs. powercut
 
  uint8_t  checksum;      // MUST BE ON LAST POSITION OF CONF STRUCTURE !
 
} plog;
 
#endif
 
 
// **********************
 
// GPS common variables
 
// **********************
 
  static int32_t  GPS_coord[2];
 
  static int32_t  GPS_home[2];
 
  static int32_t  GPS_hold[2];
 
  static uint8_t  GPS_numSat;
 
  static uint16_t GPS_distanceToHome;                          // distance to home  - unit: meter
 
  static int16_t  GPS_directionToHome;                        // direction to home - unit: degree
 
  static uint16_t GPS_altitude;                                // GPS altitude      - unit: meter
 
  static uint16_t GPS_speed;                                  // GPS speed        - unit: cm/s
 
  static uint8_t  GPS_update = 0;                              // a binary toogle to distinct a GPS position update
 
  static int16_t  GPS_angle[2] = { 0, 0};                      // the angles that must be applied for GPS correction
 
  static uint16_t GPS_ground_course = 0;                      //                  - unit: degree*10
 
  static uint8_t  GPS_Present = 0;                            // Checksum from Gps serial
 
  static uint8_t  GPS_Enable  = 0;
 
 
  #define LAT  0
 
  #define LON  1
 
  // The desired bank towards North (Positive) or South (Negative) : latitude
 
  // The desired bank towards East (Positive) or West (Negative)  : longitude
 
  static int16_t  nav[2];
 
  static int16_t  nav_rated[2];    //Adding a rate controller to the navigation to make it smoother
 
 
  // default POSHOLD control gains
 
  #define POSHOLD_P              .11
 
  #define POSHOLD_I              0.0
 
  #define POSHOLD_IMAX          20        // degrees
 
 
  #define POSHOLD_RATE_P        2.0
 
  #define POSHOLD_RATE_I        0.08      // Wind control
 
  #define POSHOLD_RATE_D        0.045    // try 2 or 3 for POSHOLD_RATE 1
 
  #define POSHOLD_RATE_IMAX      20        // degrees
 
 
  // default Navigation PID gains
 
  #define NAV_P                  1.4
 
  #define NAV_I                  0.20      // Wind control
 
  #define NAV_D                  0.08      //
 
  #define NAV_IMAX              20        // degrees
 
 
  /////////////////////////////////////////////////////////////////////////////////////////////////////////////
 
  // Serial GPS only variables
 
  //navigation mode
 
  #define NAV_MODE_NONE          0
 
  #define NAV_MODE_POSHOLD      1
 
  #define NAV_MODE_WP            2
 
  static uint8_t nav_mode = NAV_MODE_NONE; // Navigation mode
 
 
  static uint8_t alarmArray[16];          // array
 
 
#if BARO
 
  static int32_t baroPressure;
 
  static int32_t baroTemperature;
 
  static int32_t baroPressureSum;
 
#endif
 
 
void annexCode() { // this code is excetuted at each loop and won't interfere with control loop if it lasts less than 650 microseconds
 
  static uint32_t calibratedAccTime;
 
  uint16_t tmp,tmp2;
 
  uint8_t axis,prop1,prop2;
 
 
  #define BREAKPOINT 1500
 
  // PITCH & ROLL only dynamic PID adjustemnt,  depending on throttle value
 
  if (rcData[THROTTLE]<BREAKPOINT) {
 
    prop2 = 100;
 
  } else {
 
    if (rcData[THROTTLE]<2000) {
 
      prop2 = 100 - (uint16_t)conf.dynThrPID*(rcData[THROTTLE]-BREAKPOINT)/(2000-BREAKPOINT);
 
    } else {
 
      prop2 = 100 - conf.dynThrPID;
 
    }
 
  }
 
 
  for(axis=0;axis<3;axis++) {
 
    tmp = min(abs(rcData[axis]-MIDRC),500);
 
    #if defined(DEADBAND)
 
      if (tmp>DEADBAND) { tmp -= DEADBAND; }
 
      else { tmp=0; }
 
    #endif
 
    if(axis!=2) { //ROLL & PITCH
 
      tmp2 = tmp/100;
 
      rcCommand[axis] = lookupPitchRollRC[tmp2] + (tmp-tmp2*100) * (lookupPitchRollRC[tmp2+1]-lookupPitchRollRC[tmp2]) / 100;
 
      prop1 = 100-(uint16_t)conf.rollPitchRate*tmp/500;
 
      prop1 = (uint16_t)prop1*prop2/100;
 
    } else {      // YAW
 
      rcCommand[axis] = tmp;
 
      prop1 = 100-(uint16_t)conf.yawRate*tmp/500;
 
    }
 
    dynP8[axis] = (uint16_t)conf.P8[axis]*prop1/100;
 
    dynD8[axis] = (uint16_t)conf.D8[axis]*prop1/100;
 
    if (rcData[axis]<MIDRC) rcCommand[axis] = -rcCommand[axis];
 
  }
 
  tmp = constrain(rcData[THROTTLE],MINCHECK,2000);
 
  tmp = (uint32_t)(tmp-MINCHECK)*1000/(2000-MINCHECK); // [MINCHECK;2000] -> [0;1000]
 
  tmp2 = tmp/100;
 
  rcCommand[THROTTLE] = lookupThrottleRC[tmp2] + (tmp-tmp2*100) * (lookupThrottleRC[tmp2+1]-lookupThrottleRC[tmp2]) / 100; // [0;1000] -> expo -> [conf.minthrottle;MAXTHROTTLE]
 
 
  if(f.HEADFREE_MODE) { //to optimize
 
    float radDiff = (heading - headFreeModeHold) * 0.0174533f; // where PI/180 ~= 0.0174533
 
    float cosDiff = cos(radDiff);
 
    float sinDiff = sin(radDiff);
 
    int16_t rcCommand_PITCH = rcCommand[PITCH]*cosDiff + rcCommand[ROLL]*sinDiff;
 
    rcCommand[ROLL] =  rcCommand[ROLL]*cosDiff - rcCommand[PITCH]*sinDiff;
 
    rcCommand[PITCH] = rcCommand_PITCH;
 
  }
 
 
  #if defined(POWERMETER_HARD)
 
    uint16_t pMeterRaw;              // used for current reading
 
    static uint16_t psensorTimer = 0;
 
    if (! (++psensorTimer % PSENSORFREQ)) {
 
      pMeterRaw =  analogRead(PSENSORPIN);
 
      //lcdprint_int16(pMeterRaw); LCDcrlf();
 
      powerValue = ( conf.psensornull > pMeterRaw ? conf.psensornull - pMeterRaw : pMeterRaw - conf.psensornull); // do not use abs(), it would induce implicit cast to uint and overrun
 
      if ( powerValue < 333) {  // only accept reasonable values. 333 is empirical
 
      #ifdef LCD_TELEMETRY
 
        if (powerValue > powerMax) powerMax = powerValue;
 
      #endif
 
      } else {
 
        powerValue = 333;
 
      }       
 
      pMeter[PMOTOR_SUM] += (uint32_t) powerValue;
 
    }
 
  #endif
 
  #if defined(BUZZER)
 
    #if defined(VBAT)
 
      static uint8_t vbatTimer = 0;
 
      static uint8_t ind = 0;
 
      uint16_t vbatRaw = 0;
 
      static uint16_t vbatRawArray[8];
 
      if (! (++vbatTimer % VBATFREQ)) {
 
        vbatRawArray[(ind++)%8] = analogRead(V_BATPIN);
 
        for (uint8_t i=0;i<8;i++) vbatRaw += vbatRawArray[i];
 
        vbat = (vbatRaw*2) / conf.vbatscale; // result is Vbatt in 0.1V steps
 
      }
 
    #endif
 
    alarmHandler(); // external buzzer routine that handles buzzer events globally now
 
  #endif 
 
 
  #if defined(RX_RSSI)
 
    static uint8_t sig = 0;
 
    uint16_t rssiRaw = 0;
 
    static uint16_t rssiRawArray[8];
 
    rssiRawArray[(sig++)%8] = analogRead(RX_RSSI_PIN);
 
    for (uint8_t i=0;i<8;i++) rssiRaw += rssiRawArray[i];
 
    rssi = rssiRaw / 8;     
 
  #endif
 
 
  if ( (calibratingA>0 && ACC ) || (calibratingG>0) ) { // Calibration phasis
 
    LEDPIN_TOGGLE;
 
  } else {
 
    if (f.ACC_CALIBRATED) {LEDPIN_OFF;}
 
    if (f.ARMED) {LEDPIN_ON;}
 
  }
 
 
  #if defined(LED_RING)
 
    static uint32_t LEDTime;
 
    if ( currentTime > LEDTime ) {
 
      LEDTime = currentTime + 50000;
 
      i2CLedRingState();
 
    }
 
  #endif
 
 
  #if defined(LED_FLASHER)
 
    auto_switch_led_flasher();
 
  #endif
 
 
  if ( currentTime > calibratedAccTime ) {
 
    if (! f.SMALL_ANGLES_25) {
 
      // the multi uses ACC and is not calibrated or is too much inclinated
 
      f.ACC_CALIBRATED = 0;
 
      LEDPIN_TOGGLE;
 
      calibratedAccTime = currentTime + 100000;
 
    } else {
 
      f.ACC_CALIBRATED = 1;
 
    }
 
  }
 
 
  #if !(defined(SPEKTRUM) && defined(PROMINI))  //Only one serial port on ProMini.  Skip serial com if Spektrum Sat in use. Note: Spek code will auto-call serialCom if GUI data detected on serial0.
 
    #if defined(GPS_PROMINI)
 
      if(GPS_Enable == 0) {serialCom();}
 
    #else
 
      serialCom();
 
    #endif
 
  #endif
 
 
  #if defined(POWERMETER)
 
    intPowerMeterSum = (pMeter[PMOTOR_SUM]/conf.pleveldiv);
 
    intPowerTrigger1 = conf.powerTrigger1 * PLEVELSCALE;
 
  #endif
 
 
  #ifdef LCD_TELEMETRY_AUTO
 
    static char telemetryAutoSequence []  = LCD_TELEMETRY_AUTO;
 
    static uint8_t telemetryAutoIndex = 0;
 
    static uint16_t telemetryAutoTimer = 0;
 
    if ( (telemetry_auto) && (! (++telemetryAutoTimer % LCD_TELEMETRY_AUTO_FREQ) )  ){
 
      telemetry = telemetryAutoSequence[++telemetryAutoIndex % strlen(telemetryAutoSequence)];
 
      LCDclear(); // make sure to clear away remnants
 
    }
 
  #endif 
 
  #ifdef LCD_TELEMETRY
 
    static uint16_t telemetryTimer = 0;
 
    if (! (++telemetryTimer % LCD_TELEMETRY_FREQ)) {
 
      #if (LCD_TELEMETRY_DEBUG+0 > 0)
 
        telemetry = LCD_TELEMETRY_DEBUG;
 
      #endif
 
      if (telemetry) lcd_telemetry();
 
    }
 
  #endif
 
 
  #if GPS & defined(GPS_LED_INDICATOR)      // modified by MIS to use STABLEPIN LED for number of sattelites indication
 
    static uint32_t GPSLEDTime;              // - No GPS FIX -> LED blink at speed of incoming GPS frames
 
    static uint8_t blcnt;                    // - Fix and sat no. bellow 5 -> LED off
 
    if(currentTime > GPSLEDTime) {          // - Fix and sat no. >= 5 -> LED blinks, one blink for 5 sat, two blinks for 6 sat, three for 7 ...
 
      if(f.GPS_FIX && GPS_numSat >= 5) {
 
        if(++blcnt > 2*GPS_numSat) blcnt = 0;
 
        GPSLEDTime = currentTime + 150000;
 
        if(blcnt >= 10 && ((blcnt%2) == 0)) {STABLEPIN_ON;} else {STABLEPIN_OFF;}
 
      }else{
 
        if((GPS_update == 1) && !f.GPS_FIX) {STABLEPIN_ON;} else {STABLEPIN_OFF;}
 
        blcnt = 0;
 
      }
 
    }
 
  #endif
 
 
  #if defined(LOG_VALUES) && (LOG_VALUES >= 2)
 
    if (cycleTime > cycleTimeMax) cycleTimeMax = cycleTime; // remember highscore
 
    if (cycleTime < cycleTimeMin) cycleTimeMin = cycleTime; // remember lowscore
 
  #endif
 
  if (f.ARMED)  {
 
    #if defined(LCD_TELEMETRY) || defined(ARMEDTIMEWARNING) || defined(LOG_PERMANENT)
 
      armedTime += (uint32_t)cycleTime;
 
    #endif
 
    #if defined(VBAT)
 
      if ( (vbat > conf.no_vbat) && (vbat < vbatMin) ) vbatMin = vbat;
 
    #endif
 
    #ifdef LCD_TELEMETRY
 
      #if BARO
 
        if ( (BaroAlt > BAROaltMax) ) BAROaltMax = BaroAlt;
 
      #endif
 
    #endif
 
  }
 
}
 
 
void setup() {
 
  #if !defined(GPS_PROMINI)
 
    SerialOpen(0,SERIAL0_COM_SPEED);
 
    #if defined(PROMICRO)
 
      SerialOpen(1,SERIAL1_COM_SPEED);
 
    #endif
 
    #if defined(MEGA)
 
      SerialOpen(1,SERIAL1_COM_SPEED);
 
      SerialOpen(2,SERIAL2_COM_SPEED);
 
      SerialOpen(3,SERIAL3_COM_SPEED);
 
    #endif
 
  #endif
 
  LEDPIN_PINMODE;
 
  POWERPIN_PINMODE;
 
  BUZZERPIN_PINMODE;
 
  STABLEPIN_PINMODE;
 
  POWERPIN_OFF;
 
  initOutput();
 
  #ifdef MULTIPLE_CONFIGURATION_PROFILES
 
    for(global_conf.currentSet=0; global_conf.currentSet<3; global_conf.currentSet++) {  // check all settings integrity
 
      readEEPROM();
 
    }
 
  #else
 
    global_conf.currentSet=0;
 
    readEEPROM();
 
  #endif
 
  readGlobalSet();
 
  readEEPROM();                                    // load current setting data
 
  blinkLED(2,40,global_conf.currentSet+1);         
 
  configureReceiver();
 
  #if defined (PILOTLAMP)
 
    PL_INIT;
 
  #endif
 
  #if defined(OPENLRSv2MULTI)
 
    initOpenLRS();
 
  #endif
 
  initSensors();
 
  #if defined(I2C_GPS) || defined(GPS_SERIAL) || defined(GPS_FROM_OSD)
 
    GPS_set_pids();
 
  #endif
 
  previousTime = micros();
 
  #if defined(GIMBAL)
 
  calibratingA = 512;
 
  #endif
 
  calibratingG = 512;
 
  calibratingB = 200;  // 10 seconds init_delay + 200 * 25 ms = 15 seconds before ground pressure settles
 
  #if defined(POWERMETER)
 
    for(uint8_t i=0;i<=PMOTOR_SUM;i++)
 
      pMeter[i]=0;
 
  #endif
 
  /************************************/
 
  #if defined(GPS_SERIAL)
 
    GPS_SerialInit();
 
    for(uint8_t i=0;i<=5;i++){
 
      GPS_NewData();
 
      LEDPIN_ON
 
      delay(20);
 
      LEDPIN_OFF
 
      delay(80);
 
    }
 
    if(!GPS_Present){
 
      SerialEnd(GPS_SERIAL);
 
      SerialOpen(0,SERIAL0_COM_SPEED);
 
    }
 
    #if !defined(GPS_PROMINI)
 
      GPS_Present = 1;
 
    #endif
 
    GPS_Enable = GPS_Present;   
 
  #endif
 
  /************************************/
 
 
  #if defined(I2C_GPS) || defined(TINY_GPS) || defined(GPS_FROM_OSD)
 
  GPS_Enable = 1;
 
  #endif
 
 
 
  #if defined(LCD_ETPP) || defined(LCD_LCD03) || defined(OLED_I2C_128x64) || defined(LCD_TELEMETRY_STEP)
 
    initLCD();
 
  #endif
 
  #ifdef LCD_TELEMETRY_DEBUG
 
    telemetry_auto = 1;
 
  #endif
 
  #ifdef LCD_CONF_DEBUG
 
    configurationLoop();
 
  #endif
 
  #ifdef LANDING_LIGHTS_DDR
 
    init_landing_lights();
 
  #endif
 
  ADCSRA |= _BV(ADPS2) ; ADCSRA &= ~_BV(ADPS1); ADCSRA &= ~_BV(ADPS0); // this speeds up analogRead without loosing too much resolution: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1208715493/11
 
  #if defined(LED_FLASHER)
 
    init_led_flasher();
 
    led_flasher_set_sequence(LED_FLASHER_SEQUENCE);
 
  #endif
 
  f.SMALL_ANGLES_25=1; // important for gyro only conf
 
  #ifdef LOG_PERMANENT
 
    // read last stored set
 
    readPLog();
 
    plog.lifetime += plog.armed_time / 1000000;
 
    plog.start++;        // #powercycle/reset/initialize events
 
    // dump plog data to terminal
 
    #ifdef LOG_PERMANENT_SHOW_AT_STARTUP
 
      dumpPLog(0);
 
    #endif
 
    plog.armed_time = 0;  // lifetime in seconds
 
    //plog.running = 0;      // toggle on arm & disarm to monitor for clean shutdown vs. powercut
 
  #endif
 
 
  debugmsg_append_str("initialization completed\n");
 
}
 
 
void go_arm() {
 
  if(calibratingG == 0 && f.ACC_CALIBRATED
 
  #if defined(FAILSAFE)
 
    && failsafeCnt < 2
 
  #endif
 
    ) {
 
    if(!f.ARMED) { // arm now!
 
      f.ARMED = 1;
 
      headFreeModeHold = heading;
 
      #if defined(VBAT)
 
        if (vbat > conf.no_vbat) vbatMin = vbat;
 
      #endif
 
      #ifdef LCD_TELEMETRY // reset some values when arming
 
        #if BARO
 
          BAROaltMax = BaroAlt;
 
        #endif
 
      #endif
 
      #ifdef LOG_PERMANENT
 
        plog.arm++;          // #arm events
 
        plog.running = 1;      // toggle on arm & disarm to monitor for clean shutdown vs. powercut
 
        // write now.
 
        writePLog();
 
      #endif
 
    }
 
  } else if(!f.ARMED) {
 
    blinkLED(2,255,1);
 
    alarmArray[8] = 1;
 
  }
 
}
 
void go_disarm() {
 
  if (f.ARMED) {
 
    f.ARMED = 0;
 
    #ifdef LOG_PERMANENT
 
      plog.disarm++;        // #disarm events
 
      plog.armed_time = armedTime ;  // lifetime in seconds
 
      if (failsafeEvents) plog.failsafe++;      // #acitve failsafe @ disarm
 
      if (i2c_errors_count > 10) plog.i2c++;          // #i2c errs @ disarm
 
      plog.running = 0;      // toggle @ arm & disarm to monitor for clean shutdown vs. powercut
 
      // write now.
 
      writePLog();
 
    #endif
 
  }
 
}
 
void servos2Neutral() {
 
  #ifdef TRI
 
    servo[5] = 1500; // we center the yaw servo in conf mode
 
    writeServos();
 
  #endif
 
  #ifdef FLYING_WING
 
    servo[0]  = conf.wing_left_mid;
 
    servo[1]  = conf.wing_right_mid;
 
    writeServos();
 
  #endif
 
  #ifdef AIRPLANE
 
    for(uint8_t i = 4; i<7 ;i++) servo[i] = 1500;
 
    writeServos();
 
  #endif
 
  #ifdef HELICOPTER
 
    servo[5] = YAW_CENTER;
 
    servo[3] = servo[4] = servo[6] = 1500;
 
    writeServos();
 
  #endif
 
}
 
 
// ******** Main Loop *********
 
void loop () {
 
  static uint8_t rcDelayCommand; // this indicates the number of time (multiple of RC measurement at 50Hz) the sticks must be maintained to run or switch off motors
 
  static uint8_t rcSticks;      // this hold sticks position for command combos
 
  uint8_t axis,i;
 
  int16_t error,errorAngle;
 
  int16_t delta,deltaSum;
 
  int16_t PTerm,ITerm,DTerm;
 
  int16_t PTermACC = 0 , ITermACC = 0 , PTermGYRO = 0 , ITermGYRO = 0;
 
  static int16_t lastGyro[3] = {0,0,0};
 
  static int16_t delta1[3],delta2[3];
 
  static int16_t errorGyroI[3] = {0,0,0};
 
  static int16_t errorAngleI[2] = {0,0};
 
  static uint32_t rcTime  = 0;
 
  static int16_t initialThrottleHold;
 
  static uint32_t timestamp_fixated = 0;
 
 
  #if defined(SPEKTRUM)
 
    if (spekFrameFlags == 0x01) readSpektrum();
 
  #endif
 
 
 
  #if defined(OPENLRSv2MULTI)
 
    Read_OpenLRS_RC();
 
  #endif
 
 
  if (currentTime > rcTime ) { // 50Hz
 
    rcTime = currentTime + 20000;
 
    computeRC();
 
    // Failsafe routine - added by MIS
 
    #if defined(FAILSAFE)
 
      if ( failsafeCnt > (5*FAILSAFE_DELAY) && f.ARMED) {                  // Stabilize, and set Throttle to specified level
 
        for(i=0; i<3; i++) rcData[i] = MIDRC;                              // after specified guard time after RC signal is lost (in 0.1sec)
 
        rcData[THROTTLE] = conf.failsafe_throttle;
 
        if (failsafeCnt > 5*(FAILSAFE_DELAY+FAILSAFE_OFF_DELAY)) {          // Turn OFF motors after specified Time (in 0.1sec)
 
          go_disarm();    // This will prevent the copter to automatically rearm if failsafe shuts it down and prevents
 
          f.OK_TO_ARM = 0; // to restart accidentely by just reconnect to the tx - you will have to switch off first to rearm
 
        }
 
        failsafeEvents++;
 
      }
 
      if ( failsafeCnt > (5*FAILSAFE_DELAY) && !f.ARMED) {  //Turn of "Ok To arm to prevent the motors from spinning after repowering the RX with low throttle and aux to arm
 
          go_disarm();    // This will prevent the copter to automatically rearm if failsafe shuts it down and prevents
 
          f.OK_TO_ARM = 0; // to restart accidentely by just reconnect to the tx - you will have to switch off first to rearm
 
      }
 
      failsafeCnt++;
 
    #endif
 
    // end of failsafe routine - next change is made with RcOptions setting
 
 
    // ------------------ STICKS COMMAND HANDLER --------------------
 
    // checking sticks positions
 
    uint8_t stTmp = 0;
 
    for(i=0;i<4;i++) {
 
      stTmp >>= 2;
 
      if(rcData[i] > MINCHECK) stTmp |= 0x80;      // check for MIN
 
      if(rcData[i] < MAXCHECK) stTmp |= 0x40;      // check for MAX
 
    }
 
    if(stTmp == rcSticks) {
 
      if(rcDelayCommand<250) rcDelayCommand++;
 
    } else rcDelayCommand = 0;
 
    rcSticks = stTmp;
 
   
 
    // perform actions   
 
    if (rcData[THROTTLE] <= MINCHECK) {            // THROTTLE at minimum
 
      errorGyroI[ROLL] = 0; errorGyroI[PITCH] = 0; errorGyroI[YAW] = 0;
 
      errorAngleI[ROLL] = 0; errorAngleI[PITCH] = 0;
 
      if (conf.activate[BOXARM] > 0) {            // Arming/Disarming via ARM BOX
 
        if ( rcOptions[BOXARM] && f.OK_TO_ARM ) go_arm(); else if (f.ARMED) go_disarm();
 
      }
 
    }
 
    if(rcDelayCommand == 20) {
 
      if(f.ARMED) {                  // actions during armed
 
        #ifdef ALLOW_ARM_DISARM_VIA_TX_YAW
 
          if (conf.activate[BOXARM] == 0 && rcSticks == THR_LO + YAW_LO + PIT_CE + ROL_CE) go_disarm();    // Disarm via YAW
 
        #endif
 
        #ifdef ALLOW_ARM_DISARM_VIA_TX_ROLL
 
          if (conf.activate[BOXARM] == 0 && rcSticks == THR_LO + YAW_CE + PIT_CE + ROL_LO) go_disarm();    // Disarm via ROLL
 
        #endif
 
      } else {                        // actions during not armed
 
        i=0;
 
        if (rcSticks == THR_LO + YAW_LO + PIT_LO + ROL_CE) {    // GYRO calibration
 
          calibratingG=512;
 
          #if GPS
 
            GPS_reset_home_position();
 
          #endif
 
          #if BARO
 
            calibratingB=10;  // calibrate baro to new ground level (10 * 25 ms = ~250 ms non blocking)
 
          #endif
 
        }
 
        #if defined(INFLIGHT_ACC_CALIBRATION) 
 
        else if (rcSticks == THR_LO + YAW_LO + PIT_HI + ROL_HI) {    // Inflight ACC calibration START/STOP
 
            if (AccInflightCalibrationMeasurementDone){                // trigger saving into eeprom after landing
 
              AccInflightCalibrationMeasurementDone = 0;
 
              AccInflightCalibrationSavetoEEProm = 1;
 
            }else{
 
              AccInflightCalibrationArmed = !AccInflightCalibrationArmed;
 
              #if defined(BUZZER)
 
              if (AccInflightCalibrationArmed) alarmArray[0]=2; else  alarmArray[0]=3;
 
              #endif
 
            }
 
        }
 
        #endif
 
        #ifdef MULTIPLE_CONFIGURATION_PROFILES
 
          if      (rcSticks == THR_LO + YAW_LO + PIT_CE + ROL_LO) i=1;    // ROLL left  -> Profile 1
 
          else if (rcSticks == THR_LO + YAW_LO + PIT_HI + ROL_CE) i=2;    // PITCH up  -> Profile 2
 
          else if (rcSticks == THR_LO + YAW_LO + PIT_CE + ROL_HI) i=3;    // ROLL right -> Profile 3
 
          if(i) {
 
            global_conf.currentSet = i-1;
 
            writeGlobalSet(0);
 
            readEEPROM();
 
            blinkLED(2,40,i);
 
            alarmArray[0] = i;
 
          }
 
        #endif
 
        if (rcSticks == THR_LO + YAW_HI + PIT_HI + ROL_CE) {            // Enter LCD config
 
          #if defined(LCD_CONF)
 
            configurationLoop(); // beginning LCD configuration
 
          #endif
 
          previousTime = micros();
 
        }
 
        #ifdef ALLOW_ARM_DISARM_VIA_TX_YAW
 
          else if (conf.activate[BOXARM] == 0 && rcSticks == THR_LO + YAW_HI + PIT_CE + ROL_CE) go_arm();      // Arm via YAW
 
        #endif
 
        #ifdef ALLOW_ARM_DISARM_VIA_TX_ROLL
 
          else if (conf.activate[BOXARM] == 0 && rcSticks == THR_LO + YAW_CE + PIT_CE + ROL_HI) go_arm();      // Arm via ROLL
 
        #endif
 
        #ifdef LCD_TELEMETRY_AUTO
 
          else if (rcSticks == THR_LO + YAW_CE + PIT_HI + ROL_LO) {              // Auto telemetry ON/OFF
 
            if (telemetry_auto) {
 
              telemetry_auto = 0;
 
              telemetry = 0;
 
            } else
 
              telemetry_auto = 1;
 
          }
 
        #endif
 
        #ifdef LCD_TELEMETRY_STEP
 
          else if (rcSticks == THR_LO + YAW_CE + PIT_HI + ROL_HI) {              // Telemetry next step
 
            telemetry = telemetryStepSequence[++telemetryStepIndex % strlen(telemetryStepSequence)];
 
            #ifdef OLED_I2C_128x64
 
              if (telemetry != 0) i2c_OLED_init();
 
            #endif
 
            LCDclear();
 
          }
 
        #endif
 
        else if (rcSticks == THR_HI + YAW_LO + PIT_LO + ROL_CE) calibratingA=512;    // throttle=max, yaw=left, pitch=min
 
        else if (rcSticks == THR_HI + YAW_HI + PIT_LO + ROL_CE) f.CALIBRATE_MAG = 1;  // throttle=max, yaw=right, pitch=min 
 
        i=0;
 
        if      (rcSticks == THR_HI + YAW_CE + PIT_HI + ROL_CE) {conf.angleTrim[PITCH]+=2; i=1;}
 
        else if (rcSticks == THR_HI + YAW_CE + PIT_LO + ROL_CE) {conf.angleTrim[PITCH]-=2; i=1;}
 
        else if (rcSticks == THR_HI + YAW_CE + PIT_CE + ROL_HI) {conf.angleTrim[ROLL] +=2; i=1;}
 
        else if (rcSticks == THR_HI + YAW_CE + PIT_CE + ROL_LO) {conf.angleTrim[ROLL] -=2; i=1;}
 
        if (i) {
 
          writeParams(1);
 
          rcDelayCommand = 0;    // allow autorepetition
 
          #if defined(LED_RING)
 
            blinkLedRing();
 
          #endif
 
        }
 
      }
 
    }
 
    #if defined(LED_FLASHER)
 
      led_flasher_autoselect_sequence();
 
    #endif
 
   
 
    #if defined(INFLIGHT_ACC_CALIBRATION)
 
      if (AccInflightCalibrationArmed && f.ARMED && rcData[THROTTLE] > MINCHECK && !rcOptions[BOXARM] ){ // Copter is airborne and you are turning it off via boxarm : start measurement
 
        InflightcalibratingA = 50;
 
        AccInflightCalibrationArmed = 0;
 
      } 
 
      if (rcOptions[BOXCALIB]) {      // Use the Calib Option to activate : Calib = TRUE Meausrement started, Land and Calib = 0 measurement stored
 
        if (!AccInflightCalibrationActive && !AccInflightCalibrationMeasurementDone){
 
          InflightcalibratingA = 50;
 
        }
 
      }else if(AccInflightCalibrationMeasurementDone && !f.ARMED){
 
        AccInflightCalibrationMeasurementDone = 0;
 
        AccInflightCalibrationSavetoEEProm = 1;
 
      }
 
    #endif
 
 
    uint16_t auxState = 0;
 
    for(i=0;i<4;i++)
 
      auxState |= (rcData[AUX1+i]<1300)<<(3*i) | (1300<rcData[AUX1+i] && rcData[AUX1+i]<1700)<<(3*i+1) | (rcData[AUX1+i]>1700)<<(3*i+2);
 
    for(i=0;i<CHECKBOXITEMS;i++)
 
      rcOptions[i] = (auxState & conf.activate[i])>0;
 
 
    // note: if FAILSAFE is disable, failsafeCnt > 5*FAILSAFE_DELAY is always false
 
    #if ACC
 
      if ( rcOptions[BOXANGLE] || (failsafeCnt > 5*FAILSAFE_DELAY) ) {
 
        // bumpless transfer to Level mode
 
        if (!f.ANGLE_MODE) {
 
          errorAngleI[ROLL] = 0; errorAngleI[PITCH] = 0;
 
          f.ANGLE_MODE = 1;
 
        } 
 
      } else {
 
        // failsafe support
 
        f.ANGLE_MODE = 0;
 
      }
 
      if ( rcOptions[BOXHORIZON] ) {
 
        f.ANGLE_MODE = 0;
 
        if (!f.HORIZON_MODE) {
 
          errorAngleI[ROLL] = 0; errorAngleI[PITCH] = 0;
 
          f.HORIZON_MODE = 1;
 
        }
 
      } else {
 
        f.HORIZON_MODE = 0;
 
      }
 
    #endif
 
 
    if (rcOptions[BOXARM] == 0) f.OK_TO_ARM = 1;
 
    #if !defined(GPS_LED_INDICATOR)
 
      if (f.ANGLE_MODE || f.HORIZON_MODE) {STABLEPIN_ON;} else {STABLEPIN_OFF;}
 
    #endif
 
 
    #if BARO
 
      #if (!defined(SUPPRESS_BARO_ALTHOLD))
 
        if (rcOptions[BOXBARO]) {
 
            if (!f.BARO_MODE) {
 
              f.BARO_MODE = 1;
 
              AltHold = EstAlt;
 
              initialThrottleHold = rcCommand[THROTTLE];
 
              errorAltitudeI = 0;
 
              BaroPID=0;
 
            }
 
        } else {
 
            f.BARO_MODE = 0;
 
        }
 
      #endif
 
      #ifdef VARIOMETER
 
        if (rcOptions[BOXVARIO]) {
 
          if (!f.VARIO_MODE) {
 
            f.VARIO_MODE = 1;
 
          }
 
        } else {
 
          f.VARIO_MODE = 0;
 
        }
 
      #endif
 
    #endif
 
    #if MAG
 
      if (rcOptions[BOXMAG]) {
 
        if (!f.MAG_MODE) {
 
          f.MAG_MODE = 1;
 
          magHold = heading;
 
        }
 
      } else {
 
        f.MAG_MODE = 0;
 
      }
 
      if (rcOptions[BOXHEADFREE]) {
 
        if (!f.HEADFREE_MODE) {
 
          f.HEADFREE_MODE = 1;
 
        }
 
      } else {
 
        f.HEADFREE_MODE = 0;
 
      }
 
      if (rcOptions[BOXHEADADJ]) {
 
        headFreeModeHold = heading; // acquire new heading
 
      }
 
    #endif
 
   
 
    #if GPS
 
      static uint8_t GPSNavReset = 1;
 
      if (f.GPS_FIX && GPS_numSat >= 5 ) {
 
        if (rcOptions[BOXGPSHOME]) {  // if both GPS_HOME & GPS_HOLD are checked => GPS_HOME is the priority
 
          if (!f.GPS_HOME_MODE)  {
 
            f.GPS_HOME_MODE = 1;
 
            f.GPS_HOLD_MODE = 0;
 
            GPSNavReset = 0;
 
            #if defined(I2C_GPS)
 
              GPS_I2C_command(I2C_GPS_COMMAND_START_NAV,0);        //waypoint zero
 
            #else // SERIAL
 
              GPS_set_next_wp(&GPS_home[LAT],&GPS_home[LON]);
 
              nav_mode    = NAV_MODE_WP;
 
            #endif
 
          }
 
        } else {
 
          f.GPS_HOME_MODE = 0;
 
          if (rcOptions[BOXGPSHOLD] && abs(rcCommand[ROLL])< AP_MODE && abs(rcCommand[PITCH]) < AP_MODE) {
 
            if (!f.GPS_HOLD_MODE) {
 
              f.GPS_HOLD_MODE = 1;
 
              GPSNavReset = 0;
 
              #if defined(I2C_GPS)
 
                GPS_I2C_command(I2C_GPS_COMMAND_POSHOLD,0);
 
              #else
 
                GPS_hold[LAT] = GPS_coord[LAT];
 
                GPS_hold[LON] = GPS_coord[LON];
 
                GPS_set_next_wp(&GPS_hold[LAT],&GPS_hold[LON]);
 
                nav_mode = NAV_MODE_POSHOLD;
 
              #endif
 
            }
 
          } else {
 
            f.GPS_HOLD_MODE = 0;
 
            // both boxes are unselected here, nav is reset if not already done
 
            if (GPSNavReset == 0 ) {
 
              GPSNavReset = 1;
 
              GPS_reset_nav();
 
            }
 
          }
 
        }
 
      } else {
 
        f.GPS_HOME_MODE = 0;
 
        f.GPS_HOLD_MODE = 0;
 
        #if !defined(I2C_GPS)
 
          nav_mode = NAV_MODE_NONE;
 
        #endif
 
      }
 
    #endif
 
   
 
    #if defined(FIXEDWING) || defined(HELICOPTER)
 
      if (rcOptions[BOXPASSTHRU]) {f.PASSTHRU_MODE = 1;}
 
      else {f.PASSTHRU_MODE = 0;}
 
    #endif
 
 
  } else { // not in rc loop
 
    static uint8_t taskOrder=0; // never call all functions in the same loop, to avoid high delay spikes
 
    if(taskOrder>4) taskOrder-=5;
 
    switch (taskOrder) {
 
      case 0:
 
        taskOrder++;
 
        #if MAG
 
          if (Mag_getADC()) break; // max 350 µs (HMC5883) // only break when we actually did something
 
        #endif
 
      case 1:
 
        taskOrder++;
 
        #if BARO
 
          if (Baro_update() != 0 ) break;
 
        #endif
 
      case 2:
 
        taskOrder++;
 
        #if BARO
 
          if (getEstimatedAltitude() !=0) break;
 
        #endif   
 
      case 3:
 
        taskOrder++;
 
        #if GPS
 
          if(GPS_Enable) GPS_NewData();
 
          break;
 
        #endif
 
      case 4:
 
        taskOrder++;
 
        #if SONAR
 
          Sonar_update();debug[2] = sonarAlt;
 
        #endif
 
        #ifdef LANDING_LIGHTS_DDR
 
          auto_switch_landing_lights();
 
        #endif
 
        #ifdef VARIOMETER
 
          if (f.VARIO_MODE) vario_signaling();
 
        #endif
 
        break;
 
    }
 
  }
 
 
  computeIMU();
 
  // Measure loop rate just afer reading the sensors
 
  currentTime = micros();
 
  cycleTime = currentTime - previousTime;
 
  previousTime = currentTime;
 
 
  #ifdef CYCLETIME_FIXATED
 
    if (conf.cycletime_fixated) {
 
      if ((micros()-timestamp_fixated)>conf.cycletime_fixated) {
 
      } else {
 
        while((micros()-timestamp_fixated)<conf.cycletime_fixated) ; // waste away
 
      }
 
      timestamp_fixated=micros();
 
    }
 
  #endif
 
  //***********************************
 
  //**** Experimental FlightModes *****
 
  //***********************************
 
  #if defined(ACROTRAINER_MODE)
 
    if(f.ANGLE_MODE){
 
      if (abs(rcCommand[ROLL]) + abs(rcCommand[PITCH]) >= ACROTRAINER_MODE ) {
 
        f.ANGLE_MODE=0;
 
        f.HORIZON_MODE=0;
 
        f.MAG_MODE=0;
 
        f.BARO_MODE=0;
 
        f.GPS_HOME_MODE=0;
 
        f.GPS_HOLD_MODE=0;
 
      }
 
    }
 
  #endif
 
 
//***********************************
 
 
  #if MAG
 
    if (abs(rcCommand[YAW]) <70 && f.MAG_MODE) {
 
      int16_t dif = heading - magHold;
 
      if (dif <= - 180) dif += 360;
 
      if (dif >= + 180) dif -= 360;
 
      if ( f.SMALL_ANGLES_25 ) rcCommand[YAW] -= dif*conf.P8[PIDMAG]>>5;
 
    } else magHold = heading;
 
  #endif
 
 
  #if BARO && (!defined(SUPPRESS_BARO_ALTHOLD))
 
    if (f.BARO_MODE) {
 
      static uint8_t isAltHoldChanged = 0;
 
      #if defined(ALTHOLD_FAST_THROTTLE_CHANGE)
 
        if (abs(rcCommand[THROTTLE]-initialThrottleHold) > ALT_HOLD_THROTTLE_NEUTRAL_ZONE) {
 
          errorAltitudeI = 0;
 
          isAltHoldChanged = 1;
 
          rcCommand[THROTTLE] += (rcCommand[THROTTLE] > initialThrottleHold) ? -ALT_HOLD_THROTTLE_NEUTRAL_ZONE : ALT_HOLD_THROTTLE_NEUTRAL_ZONE;
 
        } else {
 
          if (isAltHoldChanged) {
 
            AltHold = EstAlt;
 
            isAltHoldChanged = 0;
 
          }
 
          rcCommand[THROTTLE] = initialThrottleHold + BaroPID;
 
        }
 
      #else
 
        static int16_t AltHoldCorr = 0;
 
        if (abs(rcCommand[THROTTLE]-initialThrottleHold)>ALT_HOLD_THROTTLE_NEUTRAL_ZONE) {
 
          // Slowly increase/decrease AltHold proportional to stick movement ( +100 throttle gives ~ +50 cm in 1 second with cycle time about 3-4ms)
 
          AltHoldCorr+= rcCommand[THROTTLE] - initialThrottleHold;
 
          if(abs(AltHoldCorr) > 500) {
 
            AltHold += AltHoldCorr/500;
 
            AltHoldCorr %= 500;
 
          }
 
          errorAltitudeI = 0;
 
          isAltHoldChanged = 1;
 
        } else if (isAltHoldChanged) {
 
          AltHold = EstAlt;
 
          isAltHoldChanged = 0;
 
        }
 
        rcCommand[THROTTLE] = initialThrottleHold + BaroPID;
 
      #endif
 
    }
 
  #endif
 
  #if GPS
 
    if ( (f.GPS_HOME_MODE || f.GPS_HOLD_MODE) && f.GPS_FIX_HOME ) {
 
      float sin_yaw_y = sin(heading*0.0174532925f);
 
      float cos_yaw_x = cos(heading*0.0174532925f);
 
      #if defined(NAV_SLEW_RATE)   
 
        nav_rated[LON]  += constrain(wrap_18000(nav[LON]-nav_rated[LON]),-NAV_SLEW_RATE,NAV_SLEW_RATE);
 
        nav_rated[LAT]  += constrain(wrap_18000(nav[LAT]-nav_rated[LAT]),-NAV_SLEW_RATE,NAV_SLEW_RATE);
 
        GPS_angle[ROLL]  = (nav_rated[LON]*cos_yaw_x - nav_rated[LAT]*sin_yaw_y) /10;
 
        GPS_angle[PITCH]  = (nav_rated[LON]*sin_yaw_y + nav_rated[LAT]*cos_yaw_x) /10;
 
      #else
 
        GPS_angle[ROLL]  = (nav[LON]*cos_yaw_x - nav[LAT]*sin_yaw_y) /10;
 
        GPS_angle[PITCH]  = (nav[LON]*sin_yaw_y + nav[LAT]*cos_yaw_x) /10;
 
      #endif
 
    } else {
 
      GPS_angle[ROLL]  = 0;
 
      GPS_angle[PITCH] = 0;
 
    }
 
  #endif
 
 
  //**** PITCH & ROLL & YAW PID ****
 
  int16_t prop;
 
  prop = min(max(abs(rcCommand[PITCH]),abs(rcCommand[ROLL])),500); // range [0;500]
 
 
  for(axis=0;axis<3;axis++) {
 
    if ((f.ANGLE_MODE || f.HORIZON_MODE) && axis<2 ) { // MODE relying on ACC
 
      // 50 degrees max inclination
 
      errorAngle = constrain((rcCommand[axis]<<1) + GPS_angle[axis],-500,+500) - angle[axis] + conf.angleTrim[axis]; //16 bits is ok here
 
      PTermACC = ((int32_t)errorAngle*conf.P8[PIDLEVEL])>>7;                          // 32 bits is needed for calculation: errorAngle*P8[PIDLEVEL] could exceed 32768  16 bits is ok for result
 
      PTermACC = constrain(PTermACC,-conf.D8[PIDLEVEL]*5,+conf.D8[PIDLEVEL]*5);
 
 
      errorAngleI[axis]    = constrain(errorAngleI[axis]+errorAngle,-10000,+10000);    // WindUp    //16 bits is ok here
 
      ITermACC              = ((int32_t)errorAngleI[axis]*conf.I8[PIDLEVEL])>>12;            // 32 bits is needed for calculation:10000*I8 could exceed 32768  16 bits is ok for result
 
    }
 
    if ( !f.ANGLE_MODE || f.HORIZON_MODE || axis == 2 ) { // MODE relying on GYRO or YAW axis
 
      if (abs(rcCommand[axis])<500) error =          (rcCommand[axis]<<6)/conf.P8[axis] ; // 16 bits is needed for calculation: 500*64 = 32000      16 bits is ok for result if P8>5 (P>0.5)
 
                              else error = ((int32_t)rcCommand[axis]<<6)/conf.P8[axis] ; // 32 bits is needed for calculation
 
 
      error -= gyroData[axis];
 
 
      PTermGYRO = rcCommand[axis];
 
     
 
      errorGyroI[axis]  = constrain(errorGyroI[axis]+error,-16000,+16000);        // WindUp  16 bits is ok here
 
      if (abs(gyroData[axis])>640) errorGyroI[axis] = 0;
 
      ITermGYRO = ((errorGyroI[axis]>>7)*conf.I8[axis])>>6;                        // 16 bits is ok here 16000/125 = 128 ; 128*250 = 32000
 
    }
 
    if ( f.HORIZON_MODE && axis<2) {
 
      PTerm = ((int32_t)PTermACC*(512-prop) + (int32_t)PTermGYRO*prop)>>9;        // the real factor should be 500, but 512 is ok
 
      ITerm = ((int32_t)ITermACC*(512-prop) + (int32_t)ITermGYRO*prop)>>9;
 
    } else {
 
      if ( f.ANGLE_MODE && axis<2) {
 
        PTerm = PTermACC;
 
        ITerm = ITermACC;
 
      } else {
 
        PTerm = PTermGYRO;
 
        ITerm = ITermGYRO;
 
      }
 
    }
 
 
    PTerm -= ((int32_t)gyroData[axis]*dynP8[axis])>>6; // 32 bits is needed for calculation 
 
 
    delta          = gyroData[axis] - lastGyro[axis];  // 16 bits is ok here, the dif between 2 consecutive gyro reads is limited to 800
 
    lastGyro[axis] = gyroData[axis];
 
    deltaSum      = delta1[axis]+delta2[axis]+delta;
 
    delta2[axis]  = delta1[axis];
 
    delta1[axis]  = delta;
 
 
    DTerm = ((int32_t)deltaSum*dynD8[axis])>>5;        // 32 bits is needed for calculation
 
                     
 
    axisPID[axis] =  PTerm + ITerm - DTerm;
 
  }
 
 
  mixTable();
 
  writeServos();
 
  writeMotors();
 
}
 
</nowiki>
 
 
 
 
<strike>Pin Function</strike>
 
 
[[File:Example.jpg]]
 
 
 
=='''Addressing'''==
 
=='''Addressing'''==
 
EachPCF8591deviceinanI 2 C-bussystemisactivatedby sending a valid address to the device. The address consists of a fixed part and a programmable part. The programmable part must be set according to the address pins A0, A1 and A2. The address always has to be sent as the first byte after the start condition in the I 2 C-bus protocol. The last bit of the address byte is the read/write-bit which sets the direction of the following data transfer (see Figs 4).
 
EachPCF8591deviceinanI 2 C-bussystemisactivatedby sending a valid address to the device. The address consists of a fixed part and a programmable part. The programmable part must be set according to the address pins A0, A1 and A2. The address always has to be sent as the first byte after the start condition in the I 2 C-bus protocol. The last bit of the address byte is the read/write-bit which sets the direction of the following data transfer (see Figs 4).
 
+
[http://192.168.0.121/mediawiki/index.php/File:5.Car_avoidobstacle.zip lianjie]
 
*Figs 4
 
*Figs 4
 +
https://www.arduino.cc/en/Main/Software
  
===Control byte===
+
=='''Control byte'''===
The second byte sent to a PCF8591 device will be stored in its control register and is required to control the device function.Theuppernibbleofthecontrolregisterisusedfor enabling the analog output, and for programming the analog inputs as single-ended or differential inputs. The lower nibble selects one of the analog input channels defined by the upper nibble (see Fig.5). If the auto-increment flag is set, the channel number is incremented automatically after each A/D conversion.<br/>
+
The second byte sent to a PCF8591 device will be stored in its control register and is required to control the device function.Theuppernibbleofthecontrolregisterisusedfor enabling the analog output, and for programming the analog inputs as single-ended or differential inputs.The lower nibble selects one of the analog input channels defined by the upper nibble (see Fig.5).If the auto-increment flag is set, the channel number is incremented automatically after each A/D conversion.<br>
If the auto-increment mode is desired in applications where the internal oscillator is used, the analog output enable flag in the control byte (bit 6) should be set. This allows the internal oscillator to run continuously, thereby preventing conversion errors resulting from oscillator start-up delay. The analog output enable flag may be reset at other times to reduce quiescent power consumption.
+
If the auto-increment mode is desired in applications where the internal oscillator is used, the analog output enable flag in the control byte (bit 6) should be set. This allows the internal oscillator to run continuously, thereby preventing conversion errors resulting from oscillator start-up delay. The analog output enable flag may be reset at other times to reduce quiescent power consumption.<br>
The selection of a non-existing input channel results in the highest available channel number being allocated. Therefore, if the auto-increment flag is set, the next selected channel will be always channel 0. The most significant bits of both nibbles are reserved for future functions and have to be set to logic 0. After a Power-on reset condition all bits of the control register are reset to logic 0. The D/A converter and the oscillator are disabled for power saving. The analog output is switched to a high-impedance state.
+
The selection of a non-existing input channel results in the highest available channel number being allocated. Therefore, if the auto-increment flag is set, the next selected channel will be always channel 0. The most significant bits of both nibbles are reserved for future functions and have to be set to logic 0. After a Power-on reset condition all bits of the control register are reset to logic 0. The D/A converter and the oscillator are disabled for power saving. The analog output is switched to a high-impedance state.<br>
  
 
*Fig.5
 
*Fig.5
  
**D/A conversion
+
== '''D/A conversion'''==
The third byte sent to a PCF8591 device is stored in the DAC data register and is converted to the corresponding analog voltage using the on-chip D/A converter. This D/A converter consists of a resistor divider chain connected to the external reference voltage with 256 taps and selection switches. The tap-decoder switches one of these taps to the DAC output line (see Fig.6).
+
The third byte sent to a PCF8591 device is stored in the DAC data register and is converted to the corresponding analog voltage using the on-chip D/A converter. This D/A converter consists of a resistor divider chain connected to the external reference voltage with 256 taps and selection switches. The tap-decoder switches one of these taps to the DAC output line (see Fig.6).<br>
The analog output voltage is buffered by an auto-zeroed unity gain amplifier. This buffer amplifier may be switched on or off by setting the analog output enable flag of thecontrol register. In the active state the output voltage is held until a further data byte is sent.
+
The analog output voltage is buffered by an auto-zeroed unity gain amplifier. This buffer amplifier may be switched on or off by setting the analog output enable flag of thecontrol register. In the active state the output voltage is held until a further data byte is sent.<br>
The on-chip D/A converter is also used for successive approximation A/D conversion. In order to release the DAC for an A/D conversion cycle the unity gain amplifier is equippedwithatrackandholdcircuit.Thiscircuitholdsthe output voltage while executing the A/D conversion.
+
The on-chip D/A converter is also used for successive approximation A/D conversion. In order to release the DAC for an A/D conversion cycle the unity gain amplifier is equippedwithatrackandholdcircuit.Thiscircuitholdsthe output voltage while executing the A/D conversion.<br>
 
The output voltage supplied to the analog output AOUT is given by the formula shown in Fig.7. The waveforms of a D/A conversion sequence are shown in Fig.8.
 
The output voltage supplied to the analog output AOUT is given by the formula shown in Fig.7. The waveforms of a D/A conversion sequence are shown in Fig.8.
 +
{| border="1" class="wikitable"
 +
|-
 +
! scope="col" | Pin
 +
! scope="col" | Name
 +
! scope="col" | Function and Note
 +
|-
 +
| 1
 +
| Reset
 +
| A switch that would reset the SeeeduinoMega
 +
|-
 +
| 2
 +
| 3.3V
 +
| 3.3V Source
 +
|-
 +
| 3
 +
| 5V
 +
| 5V Source
 +
|-
 +
| 4
 +
| Gnd
 +
| Ground
 +
|-
 +
| 5<br>
 +
| Vin<br>
 +
| A connection to the main source, this is used when the shield's supply is to be taken from the main power source
 +
|-
 +
| 0~7
 +
| ADC / GPIO:PF0-PF7
 +
| Analog to Digital channels multiplexed with Port-F, used to interface with analog sensors like potentiometers, voltage , current, temperature, pressure, humidity sensors as well as analog gyroscopes and accelerometers
 +
|-
 +
| 8~9
 +
| GPIO:PH5-PH6
 +
| General Purpose Input Output Pins<br>
 +
|-
 +
| 10~13<br>
 +
| GPIO:PB4-PB7<br>
 +
| General Purpose Input Output Pins<br>
 +
|-
 +
| 14<br>
 +
| GND<br>
 +
| A connection to the ground<br>
 +
|-
 +
| 15<br>
 +
| AREF<br>
 +
| The analog reference used as reference for the Seeeduino Mega’s ADC channels, Analog reference is decoupled to the ground using a capacitor for stability purposes.<br>
 +
|-
 +
| 0<br>
 +
| GPIO:PE0/RX0<br>
 +
| Receive channel for USART0<br>
 +
|-
 +
| 1<br>
 +
| GPIO:PE1/TX0<br>
 +
| Transmit channel for USART0<br>
 +
|-
 +
| 2~3<br>
 +
| GPIO:PE4-PE5<br>
 +
| General Purpose Input Output Pins<br>
 +
|-
 +
| 4<br>
 +
| GPIO:PG5<br>
 +
| General Purpose Input Output Pin<br>
 +
|-
 +
| 5<br>
 +
| GPIO:PE3<br>
 +
| General Purpose Input Output Pin<br>
 +
|-
 +
| 6~7<br>
 +
| GPIO:PH3-PH4<br>
 +
| General Purpose Input Output Pins<br>
 +
|-
 +
| <br>
 +
| ICSP<br>
 +
| <br>
 +
|-
 +
| 8~15<br>
 +
| ADC / GPIO:PK0-PK7<br>
 +
| 8 Analog to Digital channels multiplexed with Port-K<br><br>
 +
|-
 +
| 1<br>
 +
| RXD1 / GPIO:PD2<br>
 +
| Receive channel for USART1<br>
 +
|-
 +
| 2<br>
 +
| TXD1 / GPIO:PD3 <br>
 +
| Transmit channel for USART1<br>
 +
|-
 +
| 3<br>
 +
| RXD2 / GPIO:PH0<br>
 +
| Receive channel for USART2<br>
 +
|-
 +
| 4<br>
 +
| TXD2 / GPIO:PH1<br>
 +
| Transmit channel for USART2<br>
 +
|-
 +
| 5<br>
 +
| RXD3 / GPIO:PJ0 <br>
 +
| Receive channel for USART3<br>
 +
|-
 +
| 6<br>
 +
| TXD3 / GPIO:PJ1<br>
 +
| Transmit channel for USART3<br>
 +
|-
 +
| I2C<br>
 +
| <br>
 +
| Also known as the Two Wire Interface, I2C is an industry standard communication protocol that is used to communicate with ADCs, EEPROMs, DACs, sensors, and microcontrollers.<br>
 +
|-
 +
| 1<br>
 +
| Vcc<br>
 +
| <br>
 +
|-
 +
| 2<br>
 +
| GND<br>
 +
| <br>
 +
|-
 +
| 3<br>
 +
| SCL / GPIO:PD0<br>
 +
| I2C-Clock<br>
 +
|-
 +
| 4<br>
 +
| SDA / GPIO:PD1<br>
 +
| I2C-Serial Data<br>
 +
|-
 +
| 22~29<br>
 +
| GPIO:PA0-PA7<br>
 +
| General Purpose Input Output Pins <br>
 +
|-
 +
| 30-37<br>
 +
| GPIO:PC0-PC7<br>
 +
| General Purpose Input Output Pins <br>
 +
|-
 +
| 38<br>
 +
| GPIO:PD7<br>
 +
| General Purpose Input Output Pin<br>
 +
|-
 +
| 39~41<br>
 +
| GPIO:PG2 - PG0<br>
 +
| General Purpose Input Output Pins <br>
 +
|-
 +
| 42~45<br>
 +
| GPIO:PL7 - PL4<br>
 +
| General Purpose Input Output Pins <br>
 +
|-
 +
| 46~49<br>
 +
| GPIO:PL3 - PL0<br>
 +
| General Purpose Input Output Pins <br>
 +
|-
 +
| SPI<br>
 +
| <br>
 +
| <br>
 +
|-
 +
| 50&nbsp; <br>
 +
| MISO / GPIO:PB3<br>
 +
| SPI - Master In Slave Out<br>
 +
|-
 +
| 51<br>
 +
| MOSI / GPIO:PB2<br>
 +
| SPI - Master Out Slave In<br>
 +
|-
 +
| 52<br>
 +
| SCK / GPIO:PB1<br>
 +
| SPI - Clock<br>
 +
|-
 +
| 53<br>
 +
| GPIO:PB0<br>
 +
| General Purpose Input Output Pin<br>
 +
|-
 +
| PH2<br>
 +
| GPIO:PH2<br>
 +
| General Purpose Input Output Pin
 +
|-
 +
| PH7<br>
 +
| GPIO:PH7<br>
 +
| General Purpose Input Output Pin<br>
 +
|-
 +
| PJ2~PJ7<br>
 +
| GPIO:PJ2-PJ7<br>
 +
| General Purpose Input Output Pins <br>
 +
|-
 +
| PD4~PD6<br>
 +
| GPIO:PD4-PD6<br>
 +
| General Purpose Input Output Pins <br>
 +
|-
 +
| PG4~PG3<br>
 +
| GPIO:PG4-PG3<br>
 +
| General Purpose Input Output Pins <br>
 +
|-
 +
| PE7<br>
 +
| GPIO:PE7<br>
 +
| General Purpose Input Output Pin<br>
 +
|-
 +
| PE6<br>
 +
| GPIO:PE6<br>
 +
| General Purpose Input Output Pin<br>
 +
|-
 +
| PE2<br>
 +
| GPIO:PE2<br>
 +
| General Purpose Input Output Pin<br>
 +
|}
  
 
*Fig.6
 
*Fig.6
Line 1,402: Line 221:
  
 
***Fig.8
 
***Fig.8
The A/D converter makes use of the successive approximation conversion technique. The on-chip D/A converter and a high-gain comparator are used temporarily during an A/D conversion cycle.
+
The A/D converter makes use of the successive approximation conversion technique. The on-chip D/A converter and a high-gain comparator are used temporarily during an A/D conversion cycle.<br>
An A/D conversion cycle is always started after sending a valid read mode address to a PCF8591 device. The A/D conversion cycle is triggered at the trailing edge of the acknowledge clock pulse and is executed while transmitting the result of the previous conversion (see Fig.9).
+
An A/D conversion cycle is always started after sending a valid read mode address to a PCF8591 device. The A/D conversion cycle is triggered at the trailing edge of the acknowledge clock pulse and is executed while transmitting the result of the previous conversion (see Fig.9).<br>
Once a conversion cycle is triggered an input voltage sample of the selected channel is stored on the chip and is converted to the corresponding 8-bit binary code.Samples picked up from differential inputs are converted to an 8-bit twos complement code (see Figs 10 and 11).
+
Once a conversion cycle is triggered an input voltage sample of the selected channel is stored on the chip and is converted to the corresponding 8-bit binary code.Samples picked up from differential inputs are converted to an 8-bit twos complement code (see Figs 10 and 11).<br>
The conversion result is stored in the ADC data register and awaits transmission. If the auto-increment flag is set the next channel is selected.
+
The conversion result is stored in the ADC data register and awaits transmission. If the auto-increment flag is set the next channel is selected.<br>
The first byte transmitted in a read cycle contains the conversion result code of the previous read cycle. After a Power-on reset condition the first byte read is a hexadecimal 80. The maximum A/D conversion rate is given by the actual speed of the I 2 C-bus.
+
The first byte transmitted in a read cycle contains the conversion result code of the previous read cycle. After a Power-on reset condition the first byte read is a hexadecimal 80. The maximum A/D conversion rate is given by the actual speed of the I 2 C-bus.<br>
  
 
#Fig.9
 
#Fig.9
Line 1,418: Line 237:
  
 
===Oscillator===
 
===Oscillator===
An on-chip oscillator generates the clock signal required for the A/D conversion cycle and for refreshing the auto-zeroed buffer amplifier. When using this oscillator the EXT pin has to be connected to V SS . At the OSC pin the oscillator frequency is available. If the EXT pin is connected to V DD the oscillator output OSC is switched to a high-impedance state allowing the user to feed an external clock signal to OSC.
+
<pre>//Turns on and off a LED ,when pressings button attach to pin12
 +
/**********************************/
 +
const int keyPin = 12; //the number of the key pin
 +
const int ledPin = 13;//the number of the led pin
 +
/**********************************/
 +
void setup()
 +
{
 +
  pinMode(keyPin,INPUT);//initialize the key pin as input
 +
  pinMode(ledPin,OUTPUT);//initialize the led pin as output
 +
}
 +
/**********************************/
 +
void loop()
 +
{
 +
  //read the state of the key value
 +
  //and check if the kye is pressed
 +
  //if it is,the state is HIGH
 +
  if(digitalRead(keyPin) ==HIGH )
 +
  {
 +
    digitalWrite(ledPin,HIGH);//turn on the led
 +
  }
 +
  else
 +
  {
 +
    digitalWrite(ledPin,LOW);//turn off the led
 +
  }
 +
}
 +
/************************************/</pre>
 +
[[Getting Started:Arduino]]
 +
[[Getting Started:Getting Started with Seeeduino]]
 +
[[Category:Arduino Compatible]]
 +
[[Category:MicroControllers]]

Latest revision as of 03:47, 7 November 2015

Addressing

EachPCF8591deviceinanI 2 C-bussystemisactivatedby sending a valid address to the device. The address consists of a fixed part and a programmable part. The programmable part must be set according to the address pins A0, A1 and A2. The address always has to be sent as the first byte after the start condition in the I 2 C-bus protocol. The last bit of the address byte is the read/write-bit which sets the direction of the following data transfer (see Figs 4). lianjie

  • Figs 4

https://www.arduino.cc/en/Main/Software

Control byte=

The second byte sent to a PCF8591 device will be stored in its control register and is required to control the device function.Theuppernibbleofthecontrolregisterisusedfor enabling the analog output, and for programming the analog inputs as single-ended or differential inputs.The lower nibble selects one of the analog input channels defined by the upper nibble (see Fig.5).If the auto-increment flag is set, the channel number is incremented automatically after each A/D conversion.
If the auto-increment mode is desired in applications where the internal oscillator is used, the analog output enable flag in the control byte (bit 6) should be set. This allows the internal oscillator to run continuously, thereby preventing conversion errors resulting from oscillator start-up delay. The analog output enable flag may be reset at other times to reduce quiescent power consumption.
The selection of a non-existing input channel results in the highest available channel number being allocated. Therefore, if the auto-increment flag is set, the next selected channel will be always channel 0. The most significant bits of both nibbles are reserved for future functions and have to be set to logic 0. After a Power-on reset condition all bits of the control register are reset to logic 0. The D/A converter and the oscillator are disabled for power saving. The analog output is switched to a high-impedance state.

  • Fig.5

D/A conversion

The third byte sent to a PCF8591 device is stored in the DAC data register and is converted to the corresponding analog voltage using the on-chip D/A converter. This D/A converter consists of a resistor divider chain connected to the external reference voltage with 256 taps and selection switches. The tap-decoder switches one of these taps to the DAC output line (see Fig.6).
The analog output voltage is buffered by an auto-zeroed unity gain amplifier. This buffer amplifier may be switched on or off by setting the analog output enable flag of thecontrol register. In the active state the output voltage is held until a further data byte is sent.
The on-chip D/A converter is also used for successive approximation A/D conversion. In order to release the DAC for an A/D conversion cycle the unity gain amplifier is equippedwithatrackandholdcircuit.Thiscircuitholdsthe output voltage while executing the A/D conversion.
The output voltage supplied to the analog output AOUT is given by the formula shown in Fig.7. The waveforms of a D/A conversion sequence are shown in Fig.8.

Pin Name Function and Note
1 Reset A switch that would reset the SeeeduinoMega
2 3.3V 3.3V Source
3 5V 5V Source
4 Gnd Ground
5
Vin
A connection to the main source, this is used when the shield's supply is to be taken from the main power source
0~7 ADC / GPIO:PF0-PF7 Analog to Digital channels multiplexed with Port-F, used to interface with analog sensors like potentiometers, voltage , current, temperature, pressure, humidity sensors as well as analog gyroscopes and accelerometers
8~9 GPIO:PH5-PH6 General Purpose Input Output Pins
10~13
GPIO:PB4-PB7
General Purpose Input Output Pins
14
GND
A connection to the ground
15
AREF
The analog reference used as reference for the Seeeduino Mega’s ADC channels, Analog reference is decoupled to the ground using a capacitor for stability purposes.
0
GPIO:PE0/RX0
Receive channel for USART0
1
GPIO:PE1/TX0
Transmit channel for USART0
2~3
GPIO:PE4-PE5
General Purpose Input Output Pins
4
GPIO:PG5
General Purpose Input Output Pin
5
GPIO:PE3
General Purpose Input Output Pin
6~7
GPIO:PH3-PH4
General Purpose Input Output Pins

ICSP

8~15
ADC / GPIO:PK0-PK7
8 Analog to Digital channels multiplexed with Port-K

1
RXD1 / GPIO:PD2
Receive channel for USART1
2
TXD1 / GPIO:PD3
Transmit channel for USART1
3
RXD2 / GPIO:PH0
Receive channel for USART2
4
TXD2 / GPIO:PH1
Transmit channel for USART2
5
RXD3 / GPIO:PJ0
Receive channel for USART3
6
TXD3 / GPIO:PJ1
Transmit channel for USART3
I2C

Also known as the Two Wire Interface, I2C is an industry standard communication protocol that is used to communicate with ADCs, EEPROMs, DACs, sensors, and microcontrollers.
1
Vcc

2
GND

3
SCL / GPIO:PD0
I2C-Clock
4
SDA / GPIO:PD1
I2C-Serial Data
22~29
GPIO:PA0-PA7
General Purpose Input Output Pins
30-37
GPIO:PC0-PC7
General Purpose Input Output Pins
38
GPIO:PD7
General Purpose Input Output Pin
39~41
GPIO:PG2 - PG0
General Purpose Input Output Pins
42~45
GPIO:PL7 - PL4
General Purpose Input Output Pins
46~49
GPIO:PL3 - PL0
General Purpose Input Output Pins
SPI


50 
MISO / GPIO:PB3
SPI - Master In Slave Out
51
MOSI / GPIO:PB2
SPI - Master Out Slave In
52
SCK / GPIO:PB1
SPI - Clock
53
GPIO:PB0
General Purpose Input Output Pin
PH2
GPIO:PH2
General Purpose Input Output Pin
PH7
GPIO:PH7
General Purpose Input Output Pin
PJ2~PJ7
GPIO:PJ2-PJ7
General Purpose Input Output Pins
PD4~PD6
GPIO:PD4-PD6
General Purpose Input Output Pins
PG4~PG3
GPIO:PG4-PG3
General Purpose Input Output Pins
PE7
GPIO:PE7
General Purpose Input Output Pin
PE6
GPIO:PE6
General Purpose Input Output Pin
PE2
GPIO:PE2
General Purpose Input Output Pin
  • Fig.6
    • Fig.7
      • Fig.8

The A/D converter makes use of the successive approximation conversion technique. The on-chip D/A converter and a high-gain comparator are used temporarily during an A/D conversion cycle.
An A/D conversion cycle is always started after sending a valid read mode address to a PCF8591 device. The A/D conversion cycle is triggered at the trailing edge of the acknowledge clock pulse and is executed while transmitting the result of the previous conversion (see Fig.9).
Once a conversion cycle is triggered an input voltage sample of the selected channel is stored on the chip and is converted to the corresponding 8-bit binary code.Samples picked up from differential inputs are converted to an 8-bit twos complement code (see Figs 10 and 11).
The conversion result is stored in the ADC data register and awaits transmission. If the auto-increment flag is set the next channel is selected.
The first byte transmitted in a read cycle contains the conversion result code of the previous read cycle. After a Power-on reset condition the first byte read is a hexadecimal 80. The maximum A/D conversion rate is given by the actual speed of the I 2 C-bus.

  1. Fig.9
    • Fig.10
    • Fig.11
Reference voltage
For the D/A and A/D conversion either a stable external voltage reference or the supply voltage has to be applied to the resistor divider chain (pins V REF and AGND). The AGND pin has to be connected to the system analog ground and may have a DC off-set with reference to V SS . A low frequency may be applied to the V REF and AGND pins. This allows the use of the D/A converter as a one-quadrant multiplier; see Chapter 15 and Fig.7. The A/D converter may also be used as a one or two quadrant analog divider. The analog input voltage is divided by the reference voltage. The result is converted to a binary code. In this application the user has to keep the reference voltage stable during the conversion cycle.

Oscillator

//Turns on and off a LED ,when pressings button attach to pin12
/**********************************/
const int keyPin = 12; //the number of the key pin
const int ledPin = 13;//the number of the led pin
/**********************************/
void setup()
{
  pinMode(keyPin,INPUT);//initialize the key pin as input 
  pinMode(ledPin,OUTPUT);//initialize the led pin as output
}
/**********************************/
void loop()
{
  //read the state of the key value
  //and check if the kye is pressed
  //if it is,the state is HIGH 
  if(digitalRead(keyPin) ==HIGH )
  {
    digitalWrite(ledPin,HIGH);//turn on the led
  }
  else
  {
    digitalWrite(ledPin,LOW);//turn off the led
  }
}
/************************************/

Getting Started:Arduino Getting Started:Getting Started with Seeeduino