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soundanalogoussoundanalogous
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initial prototype of SPI implementation
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‎examples/StandardFirmataPlus/StandardFirmataPlus.ino

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@@ -52,6 +52,8 @@
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// Arduino IDE v1.6.6 or higher. Hardware serial should work back to Arduino 1.0.
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#include "utility/SerialFirmata.h"
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#include "utility/SPIFirmata.h"
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#define I2C_WRITE B00000000
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#define I2C_READ B00001000
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#define I2C_READ_CONTINUOUSLY B00010000
@@ -76,6 +78,10 @@
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SerialFirmata serialFeature;
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#endif
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#ifdef FIRMATA_SPI_FEATURE
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SPIFirmata spiFeature;
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#endif
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/* analog inputs */
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int analogInputsToReport = 0; // bitwise array to store pin reporting
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@@ -378,6 +384,11 @@ void setPinModeCallback(byte pin, int mode)
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case PIN_MODE_SERIAL:
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#ifdef FIRMATA_SERIAL_FEATURE
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serialFeature.handlePinMode(pin, PIN_MODE_SERIAL);
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#endif
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break;
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case PIN_MODE_SPI:
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#ifdef FIRMATA_SPI_FEATURE
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spiFeature.handlePinMode(pin, PIN_MODE_SPI);
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#endif
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break;
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default:
@@ -684,6 +695,9 @@ void sysexCallback(byte command, byte argc, byte *argv)
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}
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#ifdef FIRMATA_SERIAL_FEATURE
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serialFeature.handleCapability(pin);
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#endif
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#ifdef FIRMATA_SPI_FEATURE
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spiFeature.handleCapability(pin);
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#endif
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Firmata.write(127);
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}
@@ -716,6 +730,12 @@ void sysexCallback(byte command, byte argc, byte *argv)
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case SERIAL_MESSAGE:
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#ifdef FIRMATA_SERIAL_FEATURE
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serialFeature.handleSysex(command, argc, argv);
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#endif
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break;
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case SPI_DATA:
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#ifdef FIRMATA_SPI_FEATURE
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spiFeature.handleSysex(command, argc, argv);
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#endif
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break;
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}
@@ -736,6 +756,10 @@ void systemResetCallback()
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serialFeature.reset();
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#endif
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#ifdef FIRMATA_SPI_FEATURE
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spiFeature.reset();
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#endif
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if (isI2CEnabled) {
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disableI2CPins();
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}

‎utility/SPIFirmata.cpp

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/*
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SPIFirmata.cpp
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Copyright (C) 2017 Jeff Hoefs. All rights reserved.
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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See file LICENSE.txt for further informations on licensing terms.
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Last updated January 3rd, 2017
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*/
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#include "SPIFirmata.h"
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SPIFirmata::SPIFirmata()
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{
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mDeviceId = 0;
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mCsPin = -1;
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}
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boolean SPIFirmata::handlePinMode(byte pin, int mode)
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{
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// ignore SS pin for now
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if (mode == PIN_MODE_SPI && pin != SS) {
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Firmata.setPinMode(pin, PIN_MODE_SPI);
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return true;
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}
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return false;
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}
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void SPIFirmata::handleCapability(byte pin)
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{
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// ignore SS pin for now
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if (IS_PIN_SPI(pin) && pin != SS) {
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Firmata.write(PIN_MODE_SPI);
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// would actually use a value that corresponds to a specific pin (MOSI, MISO, SCK)
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// for now, just set to 1
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Firmata.write(1);
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}
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}
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boolean SPIFirmata::handleSysex(byte command, byte argc, byte *argv)
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{
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if (command == SPI_DATA) {
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byte mode = argv[0];
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// not using channel yet
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byte channel = argv[1] & SPI_CHANNEL_MASK;
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switch (mode) {
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case SPI_CONFIG:
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SPI.begin();
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break;
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case SPI_BEGIN_TRANSACTION:
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{
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mDeviceId = argv[1] >> 2;
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byte bitOrder = argv[2] & SPI_BIT_ORDER_MASK;
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byte dataMode = argv[2] >> 1;
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long clockSpeed = (long)argv[3] | ((long)argv[4] << 7) | ((long)argv[5] << 14) |
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((long)argv[6] << 21) | ((long)argv[7] << 28);
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if (argc > 8) {
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mCsPin = argv[8];
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pinMode(mCsPin, OUTPUT);
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// protect the CS pin
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Firmata.setPinMode(mCsPin, PIN_MODE_SPI);
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}
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SPISettings settings(clockSpeed, bitOrder, dataMode);
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SPI.beginTransaction(settings);
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break;
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}
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case SPI_END_TRANSACTION:
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SPI.endTransaction();
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break;
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case SPI_TRANSFER:
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{
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byte transferOptions = argv[2] & SPI_TRANSFER_OPTS_MASK;
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byte numBytes = argv[3];
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boolean csIsActive = false;
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byte csStartVal = LOW;
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byte csEndVal = HIGH;
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boolean csStartOnly = false;
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boolean csEndOnly = false;
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//boolean csToggle = false;
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if (mCsPin >= 0) {
90+
if (argv[2] & SPI_CS_ACTIVE_MASK) {
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csIsActive = true;
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if (argv[2] & SPI_CS_START_ONLY_MASK) csStartOnly = true;
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if (argv[2] & SPI_CS_END_ONLY_MASK) csEndOnly = true;
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// TODO - handle csToggle
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// if (argv[2] & SPI_CS_TOGGLE_MASK) csToggle = true;
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if (argv[2] & SPI_CS_INVERT_VAL_MASK) {
97+
csStartVal = HIGH;
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csStartVal = LOW;
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}
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}
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}
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if ((csIsActive || csStartOnly) && !csEndOnly) {
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digitalWrite(mCsPin, csStartVal);
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}
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if (transferOptions == SPI_READ_WRITE) {
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readWrite(channel, numBytes, argc, argv);
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} else if (transferOptions == SPI_READ_ONLY) {
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readOnly(channel, numBytes);
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} else if (transferOptions == SPI_WRITE_ONLY) {
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writeOnly(channel, numBytes, argc, argv);
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} else {
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// TODO - handle error
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Firmata.sendString("No transferOptions set");
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}
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if ((csIsActive || csEndOnly) && !csStartOnly) {
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digitalWrite(mCsPin, csEndVal);
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}
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break; // SPI_TRANSFER
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}
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case SPI_END:
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SPI.end();
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break;
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} // end switch
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return true;
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}
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return false;
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}
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void SPIFirmata::reset()
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{
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mCsPin = -1;
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mDeviceId = 0;
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}
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void SPIFirmata::readWrite(byte channel, byte numBytes, byte argc, byte *argv)
139+
{
140+
Firmata.sendString("readWrite");
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byte offset = 4; // mode + channel + opts + numBytes
142+
if (numBytes * 2 != argc - offset) {
143+
// TODO - handle error
144+
Firmata.sendString("fails numBytes test");
145+
}
146+
byte buffer[numBytes];
147+
byte bufferIndex = 0;
148+
for (byte i = 0; i < numBytes * 2; i += 2) {
149+
bufferIndex = (i + 1) / 2;
150+
buffer[bufferIndex] = argv[i + offset + 1] << 7 | argv[i + offset];
151+
}
152+
SPI.transfer(buffer, numBytes);
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reply(channel, numBytes, buffer);
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}
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157+
// TODO - eliminate duplication between readWrite and writeOnly
158+
void SPIFirmata::writeOnly(byte channel, byte numBytes, byte argc, byte *argv)
159+
{
160+
Firmata.sendString("writeOnly");
161+
byte offset = 4;
162+
if (numBytes * 2 != argc - offset) {
163+
// TODO - handle error
164+
Firmata.sendString("fails numBytes test");
165+
}
166+
167+
byte buffer[numBytes];
168+
byte bufferIndex = 0;
169+
for (byte i = 0; i < numBytes * 2; i += 2) {
170+
bufferIndex = (i + 1) / 2;
171+
buffer[bufferIndex] = argv[i + offset + 1] << 7 | argv[i + offset];
172+
}
173+
SPI.transfer(buffer, numBytes);
174+
}
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176+
// TODO - combine readWrite and readOnly by sending zero for each byte read
177+
// in read-only mode.
178+
// That leaves us with read and writeOnly
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void SPIFirmata::readOnly(byte channel, byte numBytes)
180+
{
181+
Firmata.sendString("readOnly");
182+
byte buffer[numBytes];
183+
for (byte i = 0; i < numBytes; i++) {
184+
buffer[i] = 0;
185+
}
186+
SPI.transfer(buffer, numBytes);
187+
188+
reply(channel, numBytes, buffer);
189+
}
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void SPIFirmata::reply(byte channel, byte numBytes, byte *buffer)
192+
{
193+
Firmata.write(START_SYSEX);
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Firmata.write(SPI_DATA);
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Firmata.write(SPI_REPLY);
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Firmata.write(mDeviceId << 2 | channel);
197+
Firmata.write(numBytes);
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199+
for (byte i = 0; i < numBytes; i++) {
200+
Firmata.write(buffer[i] & 0x7F);
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Firmata.write(buffer[i] >> 7 & 0x7F);
202+
}
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204+
Firmata.write(END_SYSEX);
205+
}

‎utility/SPIFirmata.h

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Original file line numberDiff line numberDiff line change
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/*
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SPIFirmata.h
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Copyright (C) 2017 Jeff Hoefs. All rights reserved.
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5+
This library is free software; you can redistribute it and/or
6+
modify it under the terms of the GNU Lesser General Public
7+
License as published by the Free Software Foundation; either
8+
version 2.1 of the License, or (at your option) any later version.
9+
10+
See file LICENSE.txt for further informations on licensing terms.
11+
12+
Last updated January 3rd, 2017
13+
*/
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15+
#ifndef SPIFirmata_h
16+
#define SPIFirmata_h
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18+
#include <Firmata.h>
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#include "FirmataFeature.h"
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#include <SPI.h>
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#define FIRMATA_SPI_FEATURE
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24+
// following 2 defines belong in FirmataConstants.h, but declaring them here
25+
// since this implementation is still a prototype
26+
#define SPI_DATA 0x68
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#define PIN_MODE_SPI 0x0C
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// SPI mode bytes
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#define SPI_CONFIG 0x00
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#define SPI_BEGIN_TRANSACTION 0x01
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#define SPI_END_TRANSACTION 0x02
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#define SPI_TRANSFER 0x03
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#define SPI_REPLY 0x04
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#define SPI_END 0x05
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// transfer options
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#define SPI_TRANSFER_OPTS_MASK 0x03
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#define SPI_READ_WRITE 0x00
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#define SPI_READ_ONLY 0x01
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#define SPI_WRITE_ONLY 0x02
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// pinOptions
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#define SPI_CS_ACTIVE_MASK 0x04
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#define SPI_CS_INVERT_VAL_MASK 0x08
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#define SPI_CS_START_ONLY_MASK 0x10
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#define SPI_CS_END_ONLY_MASK 0x20
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#define SPI_CS_TOGGLE_MASK 0x40
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#define SPI_CHANNEL_MASK 0x03
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#define SPI_DEVICE_ID_MASK 0x7C
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#define SPI_BIT_ORDER_MASK 0x01
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class SPIFirmata: public FirmataFeature
56+
{
57+
public:
58+
SPIFirmata();
59+
boolean handlePinMode(byte pin, int mode);
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void handleCapability(byte pin);
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boolean handleSysex(byte command, byte argc, byte *argv);
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void reset();
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private:
65+
signed char mCsPin;
66+
byte mDeviceId;
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void readWrite(byte channel, byte numBytes, byte argc, byte *argv);
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void readOnly(byte channel, byte numBytes);
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void writeOnly(byte channel, byte numBytes, byte argc, byte *argv);
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void reply(byte channel, byte numBytes, byte *buffer);
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};
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#endif /* SPIFirmata_h */

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