StandardFirmata \ Learning \ Wiring ALPHA 1.0
Author: Hernando Barragán
Description: Wiring is an electronic sketchbook and hardware electronics for developing ideas. It is a context for learning fundamentals of computer programming and prototyping with electronics within the context of the electronic arts.
Keywords: Wiring, Processing, Interactive Media, Electronic Arts, Programming, C, C++, Hernando Barragán

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This example is for Wiring version 0023+. If you have a previous version, use the examples included with your software. If you see any errors or have comments, please let us know.

Copyright (C) 2006-2008 Hans-Christoph Steiner. All rights reserved.
This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version.
See file LICENSE.txt for further informations on licensing terms.
formatted using the GNU C formatting and indenting

    /*
     * TODO: use Program Control to load stored profiles from EEPROM
     */

    #include <Firmata.h>
    #include <Servo.h>

    /*==============================================================================
     * GLOBAL VARIABLES
     *============================================================================*/

    /* analog inputs */
    int analogInputsToReport = 0; // bitwise array to store pin reporting
    int analogPin = 0; // counter for reading analog pins

    /* digital pins */
    byte reportPINs[TOTAL_PORTS];   // PIN == input port
    byte previousPINs[TOTAL_PORTS]; // PIN == input port
    byte pinStatus[TOTAL_DIGITAL_PINS]; // store pin status, default OUTPUT
    byte portStatus[TOTAL_PORTS];

    /* timer variables */
    unsigned long currentMillis;     // store the current value from millis()
    unsigned long nextExecuteMillis; // for comparison with currentMillis
    int samplingInterval = 19;      // how often to run the main loop (in ms)

    Servo servos[MAX_SERVOS];

    /*==============================================================================
     * FUNCTIONS
     *============================================================================*/

    void outputPort(byte portNumber, byte portValue)
    {
      portValue = portValue &~ portStatus[portNumber];
      if(previousPINs[portNumber] != portValue) {
        Firmata.sendDigitalPort(portNumber, portValue);
        previousPINs[portNumber] = portValue;
        Firmata.sendDigitalPort(portNumber, portValue);
      }
    }

    /* -----------------------------------------------------------------------------
     * check all the active digital inputs for change of state, then add any events
     * to the Serial output queue using Serial.print() */
    void checkDigitalInputs(void)
    {
      byte i, tmp;
      for(i=0; i < TOTAL_PORTS; i++) {
        if(reportPINs[i]) {
          switch(i) {
          case 0:
            outputPort(0, PIND &~ B00000011); // ignore Rx/Tx 0/1
            break;
          case 1:
            outputPort(1, PINB);
            break;
          case ANALOG_PORT:
            outputPort(ANALOG_PORT, PINC);
            break;
          }
        }
      }
    }

    // -----------------------------------------------------------------------------
    /* sets the pin mode to the correct state and sets the relevant bits in the
     * two bit-arrays that track Digital I/O and PWM status
     */
    void setPinModeCallback(byte pin, int mode) {
      byte port = 0;
      byte offset = 0;

      // TODO: abstract for different boards
      if (pin < 8) {
        port = 0;
        offset = 0;
      } else if (pin < 14) {
        port = 1;
        offset = 8;
      } else if (pin < 22) {
        port = 2;
        offset = 14;
      }

      if(pin > 1) { // ignore RxTx (pins 0 and 1)
        if (isServoSupportedPin(pin) && mode != SERVO)
          if (servos[pin - FIRST_SERVO_PIN].attached())
            servos[pin - FIRST_SERVO_PIN].detach();
        if(pin > 13)
          reportAnalogCallback(pin - 14, mode == ANALOG ? 1 : 0); // turn on/off reporting
        switch(mode) {
        case ANALOG:
          digitalWrite(pin, LOW); // disable internal pull-ups and fall thru to 'case INPUT:'
        case INPUT:
          pinStatus[pin] = mode;
          pinMode(pin, INPUT);
          portStatus[port] = portStatus[port] &~ (1 << (pin - offset));
          break;
        case OUTPUT:
          digitalWrite(pin, LOW); // disable PWM and fall thru to 'case PWM:'
        case PWM:
          pinStatus[pin] = mode;
          pinMode(pin, OUTPUT);
          portStatus[port] = portStatus[port] | (1 << (pin - offset));
          break;
        case SERVO:
          // TODO: Support Arduino Mega
          if (isServoSupportedPin(pin)) {
            pinStatus[pin] = mode;
            if (!servos[pin - FIRST_SERVO_PIN].attached())
              servos[pin - FIRST_SERVO_PIN].attach(pin);
          } else
            Firmata.sendString("Servo only on pins from 2 to 13");
          break;
        case I2C:
          pinStatus[pin] = mode;
          Firmata.sendString("I2C mode not yet supported");
          break;
        default:
          Firmata.sendString("Unknown pin mode"); // TODO: put error msgs in EEPROM
        }
        // TODO: save status to EEPROM here, if changed
      }
    }

    void analogWriteCallback(byte pin, int value)
    {
      switch(pinStatus[pin]) {
      case SERVO:
        if (isServoSupportedPin(pin))
          servos[pin - FIRST_SERVO_PIN].write(value);
        break;
      case PWM:
        analogWrite(pin, value);
        break;
      }
    }

    void digitalWriteCallback(byte port, int value)
    {
      switch(port) {
      case 0: // pins 2-7 (don't change Rx/Tx, pins 0 and 1)
        // 0xFF03 == B1111111100000011    0x03 == B00000011
        PORTD = (value &~ 0xFF03) | (PORTD & 0x03);
        break;
      case 1: // pins 8-13 (14,15 are disabled for the crystal)
        PORTB = (byte)value;
        break;
      case 2: // analog pins used as digital
        byte pin;
        byte pinModeMask;
        for(pin=0; pin<8; pin++)
          if(pinStatus[pin] == OUTPUT)
            pinModeMask += 1 << pin;
        PORTC = (byte)value & pinModeMask;
        break;
      }
    }

    // -----------------------------------------------------------------------------
    /* sets bits in a bit array (int) to toggle the reporting of the analogIns
     */
    //void FirmataClass::setAnalogPinReporting(byte pin, byte state) {
    //}
    void reportAnalogCallback(byte pin, int value)
    {
      if(value == 0) {
        analogInputsToReport = analogInputsToReport &~ (1 << pin);
      }
      else { // everything but 0 enables reporting of that pin
        analogInputsToReport = analogInputsToReport | (1 << pin);
      }
      // TODO: save status to EEPROM here, if changed
    }

    void reportDigitalCallback(byte port, int value)
    {
      reportPINs[port] = (byte)value;
      if(port == ANALOG_PORT) // turn off analog reporting when used as digital
        analogInputsToReport = 0;
    }

    /*==============================================================================
     * SYSEX-BASED commands
     *============================================================================*/

    void sysexCallback(byte command, byte argc, byte *argv)
    {
      switch(command) {
      case SERVO_CONFIG:
        if(argc > 4) {
          // these vars are here for clarity, they'll optimized away by the compiler
          byte pin = argv[0];
          int minPulse = argv[1] + (argv[2] << 7);
          int maxPulse = argv[3] + (argv[4] << 7);

          if (isServoSupportedPin(pin)) {
            // servos are pins from 2 to 13, so offset for array
            if (servos[pin - FIRST_SERVO_PIN].attached())
              servos[pin - FIRST_SERVO_PIN].detach();
            servos[pin - FIRST_SERVO_PIN].attach(pin, minPulse, maxPulse);
            setPinModeCallback(pin, SERVO);
          }
        }
        break;
      case SAMPLING_INTERVAL:
        if (argc > 1)
          samplingInterval = argv[0] + (argv[1] << 7);
        else
          Firmata.sendString("Not enough data");
        break;
      }
    }

    boolean isServoSupportedPin(byte pin)
    {
      return ((FIRST_SERVO_PIN <= pin) && (pin <= (FIRST_SERVO_PIN + MAX_SERVOS)));
    }

    /*==============================================================================
     * SETUP()
     *============================================================================*/
    void setup()
    {
      byte i;

      Firmata.setFirmwareVersion(2, 1);

      Firmata.attach(ANALOG_MESSAGE, analogWriteCallback);
      Firmata.attach(DIGITAL_MESSAGE, digitalWriteCallback);
      Firmata.attach(REPORT_ANALOG, reportAnalogCallback);
      Firmata.attach(REPORT_DIGITAL, reportDigitalCallback);
      Firmata.attach(SET_PIN_MODE, setPinModeCallback);
      Firmata.attach(START_SYSEX, sysexCallback);

      portStatus[0] = B00000011;  // ignore Tx/RX pins
      portStatus[1] = B11000000;  // ignore 14/15 pins
      portStatus[2] = B00000000;

      for(i=0; i < FIRST_ANALOG_PIN; ++i) {
        setPinModeCallback(i,OUTPUT);
      }
      // set all outputs to 0 to make sure internal pull-up resistors are off
      PORTB = 0; // pins 8-15
      PORTC = 0; // analog port
      PORTD = 0; // pins 0-7

      // TODO rethink the init, perhaps it should report analog on default
      for(i=0; i<TOTAL_PORTS; ++i) {
        reportPINs[i] = false;
      }
      // TODO: load state from EEPROM here

      /* send digital inputs here, if enabled, to set the initial state on the
       * host computer, since once in the loop(), this firmware will only send
       * digital data on change. */
      if(reportPINs[0]) outputPort(0, PIND &~ B00000011); // ignore Rx/Tx 0/1
      if(reportPINs[1]) outputPort(1, PINB);
      if(reportPINs[ANALOG_PORT]) outputPort(ANALOG_PORT, PINC);

      Firmata.begin(57600);
    }

    /*==============================================================================
     * LOOP()
     *============================================================================*/
    void loop()
    {
      /* DIGITALREAD - as fast as possible, check for changes and output them to the
       * FTDI buffer using Serial.print()  */
      checkDigitalInputs();
      currentMillis = millis();
      if(currentMillis > nextExecuteMillis) {
        nextExecuteMillis = currentMillis + samplingInterval;
        /* SERIALREAD - Serial.read() uses a 128 byte circular buffer, so handle
         * all serialReads at once, i.e. empty the buffer */
        while(Firmata.available())
          Firmata.processInput();
        /* SEND FTDI WRITE BUFFER - make sure that the FTDI buffer doesn't go over
         * 60 bytes. use a timer to sending an event character every 4 ms to
         * trigger the buffer to dump. */

        /* ANALOGREAD - right after the event character, do all of the
         * analogReads().  These only need to be done every 4ms. */
        for(analogPin=0;analogPin<TOTAL_ANALOG_PINS;analogPin++) {
          if( analogInputsToReport & (1 << analogPin) ) {
            Firmata.sendAnalog(analogPin, analogRead(analogPin));
          }
        }
      }
    }