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Diffstat (limited to 'libraries/Firmata/examples/I2CFirmata')
| -rw-r--r-- | libraries/Firmata/examples/I2CFirmata/I2CFirmata.pde | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/libraries/Firmata/examples/I2CFirmata/I2CFirmata.pde b/libraries/Firmata/examples/I2CFirmata/I2CFirmata.pde new file mode 100644 index 0000000..11202e9 --- /dev/null +++ b/libraries/Firmata/examples/I2CFirmata/I2CFirmata.pde @@ -0,0 +1,217 @@ +/* + Copyright (C) 2009 Jeff Hoefs. All rights reserved. + Copyright (C) 2009 Shigeru Kobayashi. 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. + */ + +#include <Wire.h> +#include <Firmata.h> + + +#define I2C_WRITE B00000000 +#define I2C_READ B00001000 +#define I2C_READ_CONTINUOUSLY B00010000 +#define I2C_STOP_READING B00011000 +#define I2C_READ_WRITE_MODE_MASK B00011000 + +#define MAX_QUERIES 8 + +unsigned long currentMillis; // store the current value from millis() +unsigned long previousMillis; // for comparison with currentMillis +unsigned int samplingInterval = 32; // default sampling interval is 33ms +unsigned int i2cReadDelayTime = 0; // default delay time between i2c read request and Wire.requestFrom() +unsigned int powerPinsEnabled = 0; // use as boolean to prevent enablePowerPins from being called more than once + +#define MINIMUM_SAMPLING_INTERVAL 10 + +#define REGISTER_NOT_SPECIFIED -1 + +struct i2c_device_info { + byte addr; + byte reg; + byte bytes; +}; + +i2c_device_info query[MAX_QUERIES]; + +byte i2cRxData[32]; +boolean readingContinuously = false; +byte queryIndex = 0; + +void readAndReportData(byte address, int theRegister, byte numBytes) +{ + if (theRegister != REGISTER_NOT_SPECIFIED) { + Wire.beginTransmission(address); + Wire.send((byte)theRegister); + Wire.endTransmission(); + delayMicroseconds(i2cReadDelayTime); // delay is necessary for some devices such as WiiNunchuck + } + else { + theRegister = 0; // fill the register with a dummy value + } + + Wire.requestFrom(address, numBytes); + + // check to be sure correct number of bytes were returned by slave + if(numBytes == Wire.available()) { + i2cRxData[0] = address; + i2cRxData[1] = theRegister; + for (int i = 0; i < numBytes; i++) { + i2cRxData[2 + i] = Wire.receive(); + } + // send slave address, register and received bytes + Firmata.sendSysex(I2C_REPLY, numBytes + 2, i2cRxData); + } + else { + if(numBytes > Wire.available()) { + Firmata.sendString("I2C Read Error: Too many bytes received"); + } else { + Firmata.sendString("I2C Read Error: Too few bytes received"); + } + } + +} + +void sysexCallback(byte command, byte argc, byte *argv) +{ + byte mode; + byte slaveAddress; + byte slaveRegister; + byte data; + int delayTime; + + if (command == I2C_REQUEST) { + mode = argv[1] & I2C_READ_WRITE_MODE_MASK; + slaveAddress = argv[0]; + + switch(mode) { + case I2C_WRITE: + Wire.beginTransmission(slaveAddress); + for (byte i = 2; i < argc; i += 2) { + data = argv[i] + (argv[i + 1] << 7); + Wire.send(data); + } + Wire.endTransmission(); + delayMicroseconds(70); // TODO is this needed? + break; + case I2C_READ: + if (argc == 6) { + // a slave register is specified + slaveRegister = argv[2] + (argv[3] << 7); + data = argv[4] + (argv[5] << 7); // bytes to read + readAndReportData(slaveAddress, (int)slaveRegister, data); + } + else { + // a slave register is NOT specified + data = argv[2] + (argv[3] << 7); // bytes to read + readAndReportData(slaveAddress, (int)REGISTER_NOT_SPECIFIED, data); + } + break; + case I2C_READ_CONTINUOUSLY: + if ((queryIndex + 1) >= MAX_QUERIES) { + // too many queries, just ignore + Firmata.sendString("too many queries"); + break; + } + query[queryIndex].addr = slaveAddress; + query[queryIndex].reg = argv[2] + (argv[3] << 7); + query[queryIndex].bytes = argv[4] + (argv[5] << 7); + readingContinuously = true; + queryIndex++; + break; + case I2C_STOP_READING: + readingContinuously = false; + queryIndex = 0; + break; + default: + break; + } + } + else if (command == SAMPLING_INTERVAL) { + samplingInterval = argv[0] + (argv[1] << 7); + + if (samplingInterval < MINIMUM_SAMPLING_INTERVAL) { + samplingInterval = MINIMUM_SAMPLING_INTERVAL; + } + + samplingInterval -= 1; + Firmata.sendString("sampling interval"); + } + + else if (command == I2C_CONFIG) { + delayTime = (argv[4] + (argv[5] << 7)); // MSB + delayTime = (delayTime << 8) + (argv[2] + (argv[3] << 7)); // add LSB + + if((argv[0] + (argv[1] << 7)) > 0) { + enablePowerPins(PORTC3, PORTC2); + } + + if(delayTime > 0) { + i2cReadDelayTime = delayTime; + } + + if(argc > 6) { + // If you extend I2C_Config, handle your data here + } + + } +} + +void systemResetCallback() +{ + readingContinuously = false; + queryIndex = 0; +} + +/* reference: BlinkM_funcs.h by Tod E. Kurt, ThingM, http://thingm.com/ */ +// Enables Pins A2 and A3 to be used as GND and Power +// so that I2C devices can be plugged directly +// into Arduino header (pins A2 - A5) +static void enablePowerPins(byte pwrpin, byte gndpin) +{ + if(powerPinsEnabled == 0) { + DDRC |= _BV(pwrpin) | _BV(gndpin); + PORTC &=~ _BV(gndpin); + PORTC |= _BV(pwrpin); + powerPinsEnabled = 1; + Firmata.sendString("Power pins enabled"); + delay(100); + } +} + +void setup() +{ + Firmata.setFirmwareVersion(2, 0); + + Firmata.attach(START_SYSEX, sysexCallback); + Firmata.attach(SYSTEM_RESET, systemResetCallback); + + for (int i = 0; i < TOTAL_PINS; ++i) { + pinMode(i, OUTPUT); + } + + Firmata.begin(57600); + Wire.begin(); +} + +void loop() +{ + while (Firmata.available()) { + Firmata.processInput(); + } + + currentMillis = millis(); + if (currentMillis - previousMillis > samplingInterval) { + previousMillis += samplingInterval; + + for (byte i = 0; i < queryIndex; i++) { + readAndReportData(query[i].addr, query[i].reg, query[i].bytes); + } + } +} |