speeduino-personal/speeduino/sensors.ino

/*
Speeduino - Simple engine management for the Arduino Mega 2560 platform
Copyright (C) Josh Stewart
A full copy of the license may be found in the projects root directory
*/
#include "sensors.h"

void initialiseADC()
{
#if defined(__AVR_ATmega1280__) || defined(__AVR_ATmega1281__) || defined(__AVR_ATmega2560__) || defined(__AVR_ATmega2561__) //AVR chips use the ISR for this

  #if defined(ANALOG_ISR)
    //This sets the ADC (Analog to Digitial Converter) to run at 250KHz, greatly reducing analog read times (MAP/TPS)
    //the code on ISR run each conversion every 25 ADC clock, conversion run about 100KHz effectively
    //making a 6250 conversions/s on 16 channels and 12500 on 8 channels devices.
    noInterrupts(); //Interrupts should be turned off when playing with any of these registers

    ADCSRB = 0x00; //ADC Auto Trigger Source is in Free Running mode
    ADMUX = 0x40;  //Select AREF as reference, ADC Left Adjust Result, Starting at channel 0

    //All of the below is the longhand version of: ADCSRA = 0xEE;
    #define ADFR 5 //Why the HELL isn't this defined in the same place as everything else (wiring.h)?!?!
    BIT_SET(ADCSRA,ADFR); //Set free running mode
    BIT_SET(ADCSRA,ADIE); //Set ADC interrupt enabled
    BIT_CLEAR(ADCSRA,ADIF); //Clear interrupt flag

    // Set ADC clock to 125KHz (Prescaler = 128)
    BIT_SET(ADCSRA,ADPS2);
    BIT_SET(ADCSRA,ADPS1);
    BIT_SET(ADCSRA,ADPS0);

    BIT_SET(ADCSRA,ADEN); //Enable ADC

    interrupts();
    BIT_SET(ADCSRA,ADSC); //Start conversion

  #else
    //This sets the ADC (Analog to Digitial Converter) to run at 1Mhz, greatly reducing analog read times (MAP/TPS) when using the standard analogRead() function
    //1Mhz is the fastest speed permitted by the CPU without affecting accuracy
    //Please see chapter 11 of 'Practical Arduino' (http://books.google.com.au/books?id=HsTxON1L6D4C&printsec=frontcover#v=onepage&q&f=false) for more detail
     BIT_SET(ADCSRA,ADPS2);
     BIT_CLEAR(ADCSRA,ADPS1);
     BIT_CLEAR(ADCSRA,ADPS0);
  #endif
#elif defined(ARDUINO_ARCH_STM32) //STM32GENERIC lib
  analogReadResolution(10); //use 10bits for analog
#endif
  MAPcurRev = 0;
  MAPcount = 0;
  MAPrunningValue = 0;
}

static inline void instanteneousMAPReading()
{
  unsigned int tempReading;
  //Instantaneous MAP readings
  #if defined(ANALOG_ISR_MAP)
    tempReading = AnChannel[pinMAP-A0];
  #else
    tempReading = analogRead(pinMAP);
    tempReading = analogRead(pinMAP);
  #endif
  //Error checking
  if( (tempReading >= VALID_MAP_MAX) || (tempReading <= VALID_MAP_MIN) ) { mapErrorCount += 1; }
  else { mapErrorCount = 0; }

  //During startup a call is made here to get the baro reading. In this case, we can't apply the ADC filter
  if(initialisationComplete == true) { currentStatus.mapADC = ADC_FILTER(tempReading, ADCFILTER_MAP, currentStatus.mapADC); } //Very weak filter
  else { currentStatus.mapADC = tempReading; } //Baro reading (No filter)

  currentStatus.MAP = fastMap10Bit(currentStatus.mapADC, configPage2.mapMin, configPage2.mapMax); //Get the current MAP value
  if(currentStatus.MAP < 0) { currentStatus.MAP = 0; } //Sanity check

}

static inline void readMAP()
{
  unsigned int tempReading;
  //MAP Sampling system
  switch(configPage2.mapSample)
  {
    case 0:
      //Instantaneous MAP readings
      instanteneousMAPReading();
      break;

    case 1:
      //Average of a cycle

      if ( (currentStatus.RPM > 0) && (currentStatus.hasSync == true) ) //If the engine isn't running, fall back to instantaneous reads
      {
        if( (MAPcurRev == currentStatus.startRevolutions) || (MAPcurRev == (currentStatus.startRevolutions+1)) ) //2 revolutions are looked at for 4 stroke. 2 stroke not currently catered for.
        {
          #if defined(ANALOG_ISR_MAP)
            tempReading = AnChannel[pinMAP-A0];
          #else
            tempReading = analogRead(pinMAP);
            tempReading = analogRead(pinMAP);
          #endif

          //Error check
          if( (tempReading < VALID_MAP_MAX) && (tempReading > VALID_MAP_MIN) )
          {
            currentStatus.mapADC = ADC_FILTER(tempReading, ADCFILTER_MAP, currentStatus.mapADC);
            MAPrunningValue += currentStatus.mapADC; //Add the current reading onto the total
            MAPcount++;
          }
          else { mapErrorCount += 1; }

          //Repeat for EMAP if it's enabled
          if(configPage6.useEMAP == true)
          {
            tempReading = analogRead(pinEMAP);
            tempReading = analogRead(pinEMAP);

            //Error check
            if( (tempReading < VALID_MAP_MAX) && (tempReading > VALID_MAP_MIN) )
            {
              currentStatus.EMAPADC = ADC_FILTER(tempReading, ADCFILTER_MAP, currentStatus.EMAPADC);
              EMAPrunningValue += currentStatus.EMAPADC; //Add the current reading onto the total
            }
            else { mapErrorCount += 1; }
          }
        }
        else
        {
          //Reaching here means that the last cylce has completed and the MAP value should be calculated
          //Sanity check
          if( (MAPrunningValue != 0) && (MAPcount != 0) )
          {
            currentStatus.mapADC = ldiv(MAPrunningValue, MAPcount).quot;
            currentStatus.MAP = fastMap10Bit(currentStatus.mapADC, configPage2.mapMin, configPage2.mapMax); //Get the current MAP value
            if(currentStatus.MAP < 0) { currentStatus.MAP = 0; } //Sanity check

            //If EMAP is enabled, the process is identical to the above
            if(configPage6.useEMAP == true)
            {
              currentStatus.EMAPADC = ldiv(EMAPrunningValue, MAPcount).quot; //Note that the MAP count can be reused here as it will always be the same count.
              currentStatus.EMAP = fastMap10Bit(currentStatus.EMAPADC, configPage2.EMAPMin, configPage2.EMAPMax);
              if(currentStatus.EMAP < 0) { currentStatus.EMAP = 0; } //Sanity check
            }
          }
          else { instanteneousMAPReading(); }
          MAPcurRev = currentStatus.startRevolutions; //Reset the current rev count
          MAPrunningValue = 0;
          EMAPrunningValue = 0; //Can reset this even if EMAP not used
          MAPcount = 0;
        }
      }
      else {  instanteneousMAPReading(); }
      break;

    case 2:
      //Minimum reading in a cycle
      if (currentStatus.RPM > 0 ) //If the engine isn't running, fall back to instantaneous reads
      {
        if( (MAPcurRev == currentStatus.startRevolutions) || (MAPcurRev == (currentStatus.startRevolutions+1)) ) //2 revolutions are looked at for 4 stroke. 2 stroke not currently catered for.
        {
          #if defined(ANALOG_ISR_MAP)
            tempReading = AnChannel[pinMAP-A0];
          #else
            tempReading = analogRead(pinMAP);
            tempReading = analogRead(pinMAP);
          #endif
          //Error check
          if( (tempReading < VALID_MAP_MAX) && (tempReading > VALID_MAP_MIN) )
          {
            if( (unsigned long)tempReading < MAPrunningValue ) { MAPrunningValue = (unsigned long)tempReading; } //Check whether the current reading is lower than the running minimum
          }
          else { mapErrorCount += 1; }
        }
        else
        {
          //Reaching here means that the last cylce has completed and the MAP value should be calculated
          currentStatus.mapADC = MAPrunningValue;
          currentStatus.MAP = fastMap10Bit(currentStatus.mapADC, configPage2.mapMin, configPage2.mapMax); //Get the current MAP value
          if(currentStatus.MAP < 0) { currentStatus.MAP = 0; } //Sanity check
          MAPcurRev = currentStatus.startRevolutions; //Reset the current rev count
          MAPrunningValue = 1023; //Reset the latest value so the next reading will always be lower
        }
      }
      else { instanteneousMAPReading(); }
      break;

    default:
    //Instantaneous MAP readings (Just in case)
    instanteneousMAPReading();
    break;
  }
}

void readTPS()
{
  currentStatus.TPSlast = currentStatus.TPS;
  currentStatus.TPSlast_time = currentStatus.TPS_time;
  #if defined(ANALOG_ISR)
    byte tempTPS = fastMap1023toX(AnChannel[pinTPS-A0], 255); //Get the current raw TPS ADC value and map it into a byte
  #else
    analogRead(pinTPS);
    byte tempTPS = fastMap1023toX(analogRead(pinTPS), 255); //Get the current raw TPS ADC value and map it into a byte
  #endif
  currentStatus.tpsADC = ADC_FILTER(tempTPS, ADCFILTER_TPS, currentStatus.tpsADC);
  byte tempADC = currentStatus.tpsADC; //The tempADC value is used in order to allow TunerStudio to recover and redo the TPS calibration if this somehow gets corrupted

  if(configPage2.tpsMax > configPage2.tpsMin)
  {
    //Check that the ADC values fall within the min and max ranges (Should always be the case, but noise can cause these to fluctuate outside the defined range).
    if (currentStatus.tpsADC < configPage2.tpsMin) { tempADC = configPage2.tpsMin; }
    else if(currentStatus.tpsADC > configPage2.tpsMax) { tempADC = configPage2.tpsMax; }
    currentStatus.TPS = map(tempADC, configPage2.tpsMin, configPage2.tpsMax, 0, 100); //Take the raw TPS ADC value and convert it into a TPS% based on the calibrated values
  }
  else
  {
    //This case occurs when the TPS +5v and gnd are wired backwards, but the user wishes to retain this configuration.
    //In such a case, tpsMin will be greater then tpsMax and hence checks and mapping needs to be reversed

    tempADC = 255 - currentStatus.tpsADC; //Reverse the ADC values

    //All checks below are reversed from the standard case above
    if (tempADC > configPage2.tpsMin) { tempADC = configPage2.tpsMin; }
    else if(tempADC < configPage2.tpsMax) { tempADC = configPage2.tpsMax; }
    currentStatus.TPS = map(tempADC, configPage2.tpsMax, configPage2.tpsMin, 0, 100);
  }

  currentStatus.TPS_time = currentLoopTime;
}

void readCLT()
{
  unsigned int tempReading;
  #if defined(ANALOG_ISR)
    tempReading = fastMap1023toX(AnChannel[pinCLT-A0], 511); //Get the current raw CLT value
  #else
    tempReading = analogRead(pinCLT);
    tempReading = fastMap1023toX(analogRead(pinCLT), 511); //Get the current raw CLT value
  #endif
  currentStatus.cltADC = ADC_FILTER(tempReading, ADCFILTER_CLT, currentStatus.cltADC);
  currentStatus.coolant = cltCalibrationTable[currentStatus.cltADC] - CALIBRATION_TEMPERATURE_OFFSET; //Temperature calibration values are stored as positive bytes. We subtract 40 from them to allow for negative temperatures
}

void readIAT()
{
  unsigned int tempReading;
  #if defined(ANALOG_ISR)
    tempReading = fastMap1023toX(AnChannel[pinIAT-A0], 511); //Get the current raw IAT value
  #else
    tempReading = analogRead(pinIAT);
    tempReading = fastMap1023toX(analogRead(pinIAT), 511); //Get the current raw IAT value
  #endif
  currentStatus.iatADC = ADC_FILTER(tempReading, ADCFILTER_IAT, currentStatus.iatADC);
  currentStatus.IAT = iatCalibrationTable[currentStatus.iatADC] - CALIBRATION_TEMPERATURE_OFFSET;
}

void readBaro()
{
  if ( configPage6.useExtBaro != 0 )
  {
    int tempReading;
    // readings
    #if defined(ANALOG_ISR_MAP)
      tempReading = AnChannel[pinBaro-A0];
    #else
      tempReading = analogRead(pinBaro);
      tempReading = analogRead(pinBaro);
    #endif

    currentStatus.baroADC = ADC_FILTER(tempReading, ADCFILTER_BARO, currentStatus.baroADC); //Very weak filter

    currentStatus.baro = fastMap10Bit(currentStatus.baroADC, configPage2.baroMin, configPage2.baroMax); //Get the current MAP value
  }
}

void readO2()
{
  unsigned int tempReading;
  #if defined(ANALOG_ISR)
    tempReading = fastMap1023toX(AnChannel[pinO2-A0], 511); //Get the current O2 value.
  #else
    tempReading = analogRead(pinO2);
    tempReading = fastMap1023toX(analogRead(pinO2), 511); //Get the current O2 value.
  #endif
  currentStatus.O2ADC = ADC_FILTER(tempReading, ADCFILTER_O2, currentStatus.O2ADC);
  currentStatus.O2 = o2CalibrationTable[currentStatus.O2ADC];
}

void readO2_2()
{
  //Second O2 currently disabled as its not being used
  //Get the current O2 value.
  unsigned int tempReading;
  #if defined(ANALOG_ISR)
    tempReading = fastMap1023toX(AnChannel[pinO2_2-A0], 511); //Get the current O2 value.
  #else
    tempReading = analogRead(pinO2_2);
    tempReading = fastMap1023toX(analogRead(pinO2_2), 511); //Get the current O2 value.
  #endif
  currentStatus.O2_2ADC = ADC_FILTER(tempReading, ADCFILTER_O2, currentStatus.O2_2ADC);
  currentStatus.O2_2 = o2CalibrationTable[currentStatus.O2_2ADC];
}

void readBat()
{
  unsigned int tempReading;
  #if defined(ANALOG_ISR)
    tempReading = fastMap1023toX(AnChannel[pinBat-A0], 245); //Get the current raw Battery value. Permissible values are from 0v to 24.5v (245)
  #else
    tempReading = analogRead(pinBat);
    tempReading = fastMap1023toX(analogRead(pinBat), 245); //Get the current raw Battery value. Permissible values are from 0v to 24.5v (245)
  #endif
  currentStatus.battery10 = ADC_FILTER(tempReading, ADCFILTER_BAT, currentStatus.battery10);
}

/*
 * The interrupt function for reading the flex sensor frequency
 * This value is incremented with every pulse and reset back to 0 once per second
 */
void flexPulse()
 {
   ++flexCounter;
 }