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Removed Wire lib for AVR
This commit is contained in:
Cristian Maglie
parent
7684a2fe85
commit
278976a587
@ -1,270 +0,0 @@
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/*
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TwoWire.cpp - TWI/I2C library for Wiring & Arduino
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Copyright (c) 2006 Nicholas Zambetti. All right 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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||||
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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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||||
Lesser General Public License for more details.
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||||
|
||||
You should have received a copy of the GNU Lesser General Public
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||||
License along with this library; if not, write to the Free Software
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||||
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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extern "C" {
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#include <stdlib.h>
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#include <string.h>
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#include <inttypes.h>
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#include "twi.h"
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}
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#include "Wire.h"
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// Initialize Class Variables //////////////////////////////////////////////////
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uint8_t TwoWire::rxBuffer[BUFFER_LENGTH];
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uint8_t TwoWire::rxBufferIndex = 0;
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uint8_t TwoWire::rxBufferLength = 0;
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uint8_t TwoWire::txAddress = 0;
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uint8_t TwoWire::txBuffer[BUFFER_LENGTH];
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uint8_t TwoWire::txBufferIndex = 0;
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uint8_t TwoWire::txBufferLength = 0;
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uint8_t TwoWire::transmitting = 0;
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void (*TwoWire::user_onRequest)(void);
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void (*TwoWire::user_onReceive)(int);
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// Constructors ////////////////////////////////////////////////////////////////
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TwoWire::TwoWire()
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{
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}
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// Public Methods //////////////////////////////////////////////////////////////
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void TwoWire::begin(void)
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{
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rxBufferIndex = 0;
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rxBufferLength = 0;
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txBufferIndex = 0;
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txBufferLength = 0;
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twi_init();
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}
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void TwoWire::begin(uint8_t address)
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{
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twi_setAddress(address);
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twi_attachSlaveTxEvent(onRequestService);
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twi_attachSlaveRxEvent(onReceiveService);
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begin();
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}
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void TwoWire::begin(int address)
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{
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begin((uint8_t)address);
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}
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uint8_t TwoWire::requestFrom(uint8_t address, uint8_t quantity)
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{
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// clamp to buffer length
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if(quantity > BUFFER_LENGTH){
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quantity = BUFFER_LENGTH;
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}
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// perform blocking read into buffer
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uint8_t read = twi_readFrom(address, rxBuffer, quantity);
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// set rx buffer iterator vars
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rxBufferIndex = 0;
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rxBufferLength = read;
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return read;
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}
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uint8_t TwoWire::requestFrom(int address, int quantity)
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{
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return requestFrom((uint8_t)address, (uint8_t)quantity);
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}
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void TwoWire::beginTransmission(uint8_t address)
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{
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// indicate that we are transmitting
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transmitting = 1;
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// set address of targeted slave
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txAddress = address;
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// reset tx buffer iterator vars
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txBufferIndex = 0;
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txBufferLength = 0;
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}
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void TwoWire::beginTransmission(int address)
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{
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beginTransmission((uint8_t)address);
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}
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uint8_t TwoWire::endTransmission(void)
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{
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// transmit buffer (blocking)
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int8_t ret = twi_writeTo(txAddress, txBuffer, txBufferLength, 1);
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// reset tx buffer iterator vars
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txBufferIndex = 0;
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txBufferLength = 0;
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// indicate that we are done transmitting
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transmitting = 0;
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return ret;
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}
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// must be called in:
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// slave tx event callback
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// or after beginTransmission(address)
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void TwoWire::write(uint8_t data)
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{
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if(transmitting){
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// in master transmitter mode
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// don't bother if buffer is full
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if(txBufferLength >= BUFFER_LENGTH){
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return;
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}
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// put byte in tx buffer
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txBuffer[txBufferIndex] = data;
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++txBufferIndex;
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// update amount in buffer
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txBufferLength = txBufferIndex;
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}else{
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// in slave send mode
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// reply to master
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twi_transmit(&data, 1);
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}
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}
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// must be called in:
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// slave tx event callback
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// or after beginTransmission(address)
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void TwoWire::write(const uint8_t *data, size_t quantity)
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{
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if(transmitting){
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// in master transmitter mode
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for(size_t i = 0; i < quantity; ++i){
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write(data[i]);
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}
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}else{
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// in slave send mode
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// reply to master
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twi_transmit(data, quantity);
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}
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}
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// must be called in:
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// slave tx event callback
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// or after beginTransmission(address)
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void TwoWire::write(const char *data)
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{
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write((uint8_t*)data, strlen(data));
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}
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// must be called in:
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// slave rx event callback
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// or after requestFrom(address, numBytes)
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int TwoWire::available(void)
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{
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return rxBufferLength - rxBufferIndex;
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}
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// must be called in:
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// slave rx event callback
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// or after requestFrom(address, numBytes)
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int TwoWire::read(void)
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{
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int value = -1;
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// get each successive byte on each call
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if(rxBufferIndex < rxBufferLength){
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value = rxBuffer[rxBufferIndex];
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++rxBufferIndex;
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}
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return value;
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}
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// must be called in:
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// slave rx event callback
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// or after requestFrom(address, numBytes)
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int TwoWire::peek(void)
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{
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int value = -1;
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if(rxBufferIndex < rxBufferLength){
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value = rxBuffer[rxBufferIndex];
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}
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return value;
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}
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void TwoWire::flush(void)
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{
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// XXX: to be implemented.
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}
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// behind the scenes function that is called when data is received
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void TwoWire::onReceiveService(uint8_t* inBytes, int numBytes)
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{
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// don't bother if user hasn't registered a callback
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if(!user_onReceive){
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return;
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}
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// don't bother if rx buffer is in use by a master requestFrom() op
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// i know this drops data, but it allows for slight stupidity
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// meaning, they may not have read all the master requestFrom() data yet
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if(rxBufferIndex < rxBufferLength){
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return;
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}
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// copy twi rx buffer into local read buffer
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// this enables new reads to happen in parallel
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for(uint8_t i = 0; i < numBytes; ++i){
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rxBuffer[i] = inBytes[i];
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}
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// set rx iterator vars
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rxBufferIndex = 0;
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rxBufferLength = numBytes;
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// alert user program
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user_onReceive(numBytes);
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}
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// behind the scenes function that is called when data is requested
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void TwoWire::onRequestService(void)
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{
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// don't bother if user hasn't registered a callback
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if(!user_onRequest){
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return;
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}
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// reset tx buffer iterator vars
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// !!! this will kill any pending pre-master sendTo() activity
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txBufferIndex = 0;
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txBufferLength = 0;
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// alert user program
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user_onRequest();
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}
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// sets function called on slave write
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void TwoWire::onReceive( void (*function)(int) )
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{
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user_onReceive = function;
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}
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// sets function called on slave read
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void TwoWire::onRequest( void (*function)(void) )
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{
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user_onRequest = function;
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}
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// Preinstantiate Objects //////////////////////////////////////////////////////
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TwoWire Wire = TwoWire();
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@ -1,69 +0,0 @@
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/*
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TwoWire.h - TWI/I2C library for Arduino & Wiring
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Copyright (c) 2006 Nicholas Zambetti. All right 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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||||
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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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||||
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You should have received a copy of the GNU Lesser General Public
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||||
License along with this library; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#ifndef TwoWire_h
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#define TwoWire_h
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#include <inttypes.h>
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#include "Stream.h"
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#define BUFFER_LENGTH 32
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class TwoWire : public Stream
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{
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private:
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static uint8_t rxBuffer[];
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static uint8_t rxBufferIndex;
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static uint8_t rxBufferLength;
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static uint8_t txAddress;
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static uint8_t txBuffer[];
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static uint8_t txBufferIndex;
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static uint8_t txBufferLength;
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static uint8_t transmitting;
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static void (*user_onRequest)(void);
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static void (*user_onReceive)(int);
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static void onRequestService(void);
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static void onReceiveService(uint8_t*, int);
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public:
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TwoWire();
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void begin();
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void begin(uint8_t);
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void begin(int);
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void beginTransmission(uint8_t);
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void beginTransmission(int);
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uint8_t endTransmission(void);
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uint8_t requestFrom(uint8_t, uint8_t);
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uint8_t requestFrom(int, int);
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virtual void write(uint8_t);
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virtual void write(const char *);
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virtual void write(const uint8_t *, size_t);
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virtual int available(void);
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virtual int read(void);
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virtual int peek(void);
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virtual void flush(void);
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void onReceive( void (*)(int) );
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void onRequest( void (*)(void) );
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};
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extern TwoWire Wire;
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#endif
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@ -1,476 +0,0 @@
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/*
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twi.c - TWI/I2C library for Wiring & Arduino
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Copyright (c) 2006 Nicholas Zambetti. All right 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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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
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Lesser General Public License for more details.
|
||||
|
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You should have received a copy of the GNU Lesser General Public
|
||||
License along with this library; if not, write to the Free Software
|
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <math.h>
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#include <stdlib.h>
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#include <inttypes.h>
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#include <avr/io.h>
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#include <avr/interrupt.h>
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#include <compat/twi.h>
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#ifndef cbi
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#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
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#endif
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#ifndef sbi
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#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))
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#endif
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#include "twi.h"
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static volatile uint8_t twi_state;
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static uint8_t twi_slarw;
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static void (*twi_onSlaveTransmit)(void);
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static void (*twi_onSlaveReceive)(uint8_t*, int);
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static uint8_t twi_masterBuffer[TWI_BUFFER_LENGTH];
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static volatile uint8_t twi_masterBufferIndex;
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static uint8_t twi_masterBufferLength;
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static uint8_t twi_txBuffer[TWI_BUFFER_LENGTH];
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static volatile uint8_t twi_txBufferIndex;
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static volatile uint8_t twi_txBufferLength;
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static uint8_t twi_rxBuffer[TWI_BUFFER_LENGTH];
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static volatile uint8_t twi_rxBufferIndex;
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static volatile uint8_t twi_error;
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/*
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* Function twi_init
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* Desc readys twi pins and sets twi bitrate
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* Input none
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* Output none
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*/
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void twi_init(void)
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{
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// initialize state
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twi_state = TWI_READY;
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#if defined(__AVR_ATmega168__) || defined(__AVR_ATmega8__) || defined(__AVR_ATmega328P__)
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// activate internal pull-ups for twi
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// as per note from atmega8 manual pg167
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sbi(PORTC, 4);
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sbi(PORTC, 5);
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#else
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// activate internal pull-ups for twi
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// as per note from atmega128 manual pg204
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sbi(PORTD, 0);
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sbi(PORTD, 1);
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#endif
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// initialize twi prescaler and bit rate
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cbi(TWSR, TWPS0);
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cbi(TWSR, TWPS1);
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TWBR = ((F_CPU / TWI_FREQ) - 16) / 2;
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/* twi bit rate formula from atmega128 manual pg 204
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SCL Frequency = CPU Clock Frequency / (16 + (2 * TWBR))
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note: TWBR should be 10 or higher for master mode
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It is 72 for a 16mhz Wiring board with 100kHz TWI */
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// enable twi module, acks, and twi interrupt
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TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWEA);
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}
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/*
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* Function twi_slaveInit
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* Desc sets slave address and enables interrupt
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* Input none
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* Output none
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*/
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void twi_setAddress(uint8_t address)
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{
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// set twi slave address (skip over TWGCE bit)
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TWAR = address << 1;
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}
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/*
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* Function twi_readFrom
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* Desc attempts to become twi bus master and read a
|
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* series of bytes from a device on the bus
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* Input address: 7bit i2c device address
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* data: pointer to byte array
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* length: number of bytes to read into array
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* Output number of bytes read
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*/
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uint8_t twi_readFrom(uint8_t address, uint8_t* data, uint8_t length)
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{
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uint8_t i;
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// ensure data will fit into buffer
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if(TWI_BUFFER_LENGTH < length){
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return 0;
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}
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// wait until twi is ready, become master receiver
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while(TWI_READY != twi_state){
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continue;
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}
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twi_state = TWI_MRX;
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// reset error state (0xFF.. no error occured)
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twi_error = 0xFF;
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// initialize buffer iteration vars
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twi_masterBufferIndex = 0;
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twi_masterBufferLength = length-1; // This is not intuitive, read on...
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// On receive, the previously configured ACK/NACK setting is transmitted in
|
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// response to the received byte before the interrupt is signalled.
|
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// Therefor we must actually set NACK when the _next_ to last byte is
|
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// received, causing that NACK to be sent in response to receiving the last
|
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// expected byte of data.
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|
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// build sla+w, slave device address + w bit
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twi_slarw = TW_READ;
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twi_slarw |= address << 1;
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// send start condition
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TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWEA) | _BV(TWINT) | _BV(TWSTA);
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// wait for read operation to complete
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while(TWI_MRX == twi_state){
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continue;
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}
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if (twi_masterBufferIndex < length)
|
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length = twi_masterBufferIndex;
|
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|
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// copy twi buffer to data
|
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for(i = 0; i < length; ++i){
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data[i] = twi_masterBuffer[i];
|
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}
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|
||||
return length;
|
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}
|
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/*
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* Function twi_writeTo
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* Desc attempts to become twi bus master and write a
|
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* series of bytes to a device on the bus
|
||||
* Input address: 7bit i2c device address
|
||||
* data: pointer to byte array
|
||||
* length: number of bytes in array
|
||||
* wait: boolean indicating to wait for write or not
|
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* Output 0 .. success
|
||||
* 1 .. length to long for buffer
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||||
* 2 .. address send, NACK received
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* 3 .. data send, NACK received
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||||
* 4 .. other twi error (lost bus arbitration, bus error, ..)
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||||
*/
|
||||
uint8_t twi_writeTo(uint8_t address, uint8_t* data, uint8_t length, uint8_t wait)
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{
|
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uint8_t i;
|
||||
|
||||
// ensure data will fit into buffer
|
||||
if(TWI_BUFFER_LENGTH < length){
|
||||
return 1;
|
||||
}
|
||||
|
||||
// wait until twi is ready, become master transmitter
|
||||
while(TWI_READY != twi_state){
|
||||
continue;
|
||||
}
|
||||
twi_state = TWI_MTX;
|
||||
// reset error state (0xFF.. no error occured)
|
||||
twi_error = 0xFF;
|
||||
|
||||
// initialize buffer iteration vars
|
||||
twi_masterBufferIndex = 0;
|
||||
twi_masterBufferLength = length;
|
||||
|
||||
// copy data to twi buffer
|
||||
for(i = 0; i < length; ++i){
|
||||
twi_masterBuffer[i] = data[i];
|
||||
}
|
||||
|
||||
// build sla+w, slave device address + w bit
|
||||
twi_slarw = TW_WRITE;
|
||||
twi_slarw |= address << 1;
|
||||
|
||||
// send start condition
|
||||
TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWEA) | _BV(TWINT) | _BV(TWSTA);
|
||||
|
||||
// wait for write operation to complete
|
||||
while(wait && (TWI_MTX == twi_state)){
|
||||
continue;
|
||||
}
|
||||
|
||||
if (twi_error == 0xFF)
|
||||
return 0; // success
|
||||
else if (twi_error == TW_MT_SLA_NACK)
|
||||
return 2; // error: address send, nack received
|
||||
else if (twi_error == TW_MT_DATA_NACK)
|
||||
return 3; // error: data send, nack received
|
||||
else
|
||||
return 4; // other twi error
|
||||
}
|
||||
|
||||
/*
|
||||
* Function twi_transmit
|
||||
* Desc fills slave tx buffer with data
|
||||
* must be called in slave tx event callback
|
||||
* Input data: pointer to byte array
|
||||
* length: number of bytes in array
|
||||
* Output 1 length too long for buffer
|
||||
* 2 not slave transmitter
|
||||
* 0 ok
|
||||
*/
|
||||
uint8_t twi_transmit(const uint8_t* data, uint8_t length)
|
||||
{
|
||||
uint8_t i;
|
||||
|
||||
// ensure data will fit into buffer
|
||||
if(TWI_BUFFER_LENGTH < length){
|
||||
return 1;
|
||||
}
|
||||
|
||||
// ensure we are currently a slave transmitter
|
||||
if(TWI_STX != twi_state){
|
||||
return 2;
|
||||
}
|
||||
|
||||
// set length and copy data into tx buffer
|
||||
twi_txBufferLength = length;
|
||||
for(i = 0; i < length; ++i){
|
||||
twi_txBuffer[i] = data[i];
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* Function twi_attachSlaveRxEvent
|
||||
* Desc sets function called before a slave read operation
|
||||
* Input function: callback function to use
|
||||
* Output none
|
||||
*/
|
||||
void twi_attachSlaveRxEvent( void (*function)(uint8_t*, int) )
|
||||
{
|
||||
twi_onSlaveReceive = function;
|
||||
}
|
||||
|
||||
/*
|
||||
* Function twi_attachSlaveTxEvent
|
||||
* Desc sets function called before a slave write operation
|
||||
* Input function: callback function to use
|
||||
* Output none
|
||||
*/
|
||||
void twi_attachSlaveTxEvent( void (*function)(void) )
|
||||
{
|
||||
twi_onSlaveTransmit = function;
|
||||
}
|
||||
|
||||
/*
|
||||
* Function twi_reply
|
||||
* Desc sends byte or readys receive line
|
||||
* Input ack: byte indicating to ack or to nack
|
||||
* Output none
|
||||
*/
|
||||
void twi_reply(uint8_t ack)
|
||||
{
|
||||
// transmit master read ready signal, with or without ack
|
||||
if(ack){
|
||||
TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWINT) | _BV(TWEA);
|
||||
}else{
|
||||
TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWINT);
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* Function twi_stop
|
||||
* Desc relinquishes bus master status
|
||||
* Input none
|
||||
* Output none
|
||||
*/
|
||||
void twi_stop(void)
|
||||
{
|
||||
// send stop condition
|
||||
TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWEA) | _BV(TWINT) | _BV(TWSTO);
|
||||
|
||||
// wait for stop condition to be exectued on bus
|
||||
// TWINT is not set after a stop condition!
|
||||
while(TWCR & _BV(TWSTO)){
|
||||
continue;
|
||||
}
|
||||
|
||||
// update twi state
|
||||
twi_state = TWI_READY;
|
||||
}
|
||||
|
||||
/*
|
||||
* Function twi_releaseBus
|
||||
* Desc releases bus control
|
||||
* Input none
|
||||
* Output none
|
||||
*/
|
||||
void twi_releaseBus(void)
|
||||
{
|
||||
// release bus
|
||||
TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWEA) | _BV(TWINT);
|
||||
|
||||
// update twi state
|
||||
twi_state = TWI_READY;
|
||||
}
|
||||
|
||||
SIGNAL(TWI_vect)
|
||||
{
|
||||
switch(TW_STATUS){
|
||||
// All Master
|
||||
case TW_START: // sent start condition
|
||||
case TW_REP_START: // sent repeated start condition
|
||||
// copy device address and r/w bit to output register and ack
|
||||
TWDR = twi_slarw;
|
||||
twi_reply(1);
|
||||
break;
|
||||
|
||||
// Master Transmitter
|
||||
case TW_MT_SLA_ACK: // slave receiver acked address
|
||||
case TW_MT_DATA_ACK: // slave receiver acked data
|
||||
// if there is data to send, send it, otherwise stop
|
||||
if(twi_masterBufferIndex < twi_masterBufferLength){
|
||||
// copy data to output register and ack
|
||||
TWDR = twi_masterBuffer[twi_masterBufferIndex++];
|
||||
twi_reply(1);
|
||||
}else{
|
||||
twi_stop();
|
||||
}
|
||||
break;
|
||||
case TW_MT_SLA_NACK: // address sent, nack received
|
||||
twi_error = TW_MT_SLA_NACK;
|
||||
twi_stop();
|
||||
break;
|
||||
case TW_MT_DATA_NACK: // data sent, nack received
|
||||
twi_error = TW_MT_DATA_NACK;
|
||||
twi_stop();
|
||||
break;
|
||||
case TW_MT_ARB_LOST: // lost bus arbitration
|
||||
twi_error = TW_MT_ARB_LOST;
|
||||
twi_releaseBus();
|
||||
break;
|
||||
|
||||
// Master Receiver
|
||||
case TW_MR_DATA_ACK: // data received, ack sent
|
||||
// put byte into buffer
|
||||
twi_masterBuffer[twi_masterBufferIndex++] = TWDR;
|
||||
case TW_MR_SLA_ACK: // address sent, ack received
|
||||
// ack if more bytes are expected, otherwise nack
|
||||
if(twi_masterBufferIndex < twi_masterBufferLength){
|
||||
twi_reply(1);
|
||||
}else{
|
||||
twi_reply(0);
|
||||
}
|
||||
break;
|
||||
case TW_MR_DATA_NACK: // data received, nack sent
|
||||
// put final byte into buffer
|
||||
twi_masterBuffer[twi_masterBufferIndex++] = TWDR;
|
||||
case TW_MR_SLA_NACK: // address sent, nack received
|
||||
twi_stop();
|
||||
break;
|
||||
// TW_MR_ARB_LOST handled by TW_MT_ARB_LOST case
|
||||
|
||||
// Slave Receiver
|
||||
case TW_SR_SLA_ACK: // addressed, returned ack
|
||||
case TW_SR_GCALL_ACK: // addressed generally, returned ack
|
||||
case TW_SR_ARB_LOST_SLA_ACK: // lost arbitration, returned ack
|
||||
case TW_SR_ARB_LOST_GCALL_ACK: // lost arbitration, returned ack
|
||||
// enter slave receiver mode
|
||||
twi_state = TWI_SRX;
|
||||
// indicate that rx buffer can be overwritten and ack
|
||||
twi_rxBufferIndex = 0;
|
||||
twi_reply(1);
|
||||
break;
|
||||
case TW_SR_DATA_ACK: // data received, returned ack
|
||||
case TW_SR_GCALL_DATA_ACK: // data received generally, returned ack
|
||||
// if there is still room in the rx buffer
|
||||
if(twi_rxBufferIndex < TWI_BUFFER_LENGTH){
|
||||
// put byte in buffer and ack
|
||||
twi_rxBuffer[twi_rxBufferIndex++] = TWDR;
|
||||
twi_reply(1);
|
||||
}else{
|
||||
// otherwise nack
|
||||
twi_reply(0);
|
||||
}
|
||||
break;
|
||||
case TW_SR_STOP: // stop or repeated start condition received
|
||||
// put a null char after data if there's room
|
||||
if(twi_rxBufferIndex < TWI_BUFFER_LENGTH){
|
||||
twi_rxBuffer[twi_rxBufferIndex] = '\0';
|
||||
}
|
||||
// sends ack and stops interface for clock stretching
|
||||
twi_stop();
|
||||
// callback to user defined callback
|
||||
twi_onSlaveReceive(twi_rxBuffer, twi_rxBufferIndex);
|
||||
// since we submit rx buffer to "wire" library, we can reset it
|
||||
twi_rxBufferIndex = 0;
|
||||
// ack future responses and leave slave receiver state
|
||||
twi_releaseBus();
|
||||
break;
|
||||
case TW_SR_DATA_NACK: // data received, returned nack
|
||||
case TW_SR_GCALL_DATA_NACK: // data received generally, returned nack
|
||||
// nack back at master
|
||||
twi_reply(0);
|
||||
break;
|
||||
|
||||
// Slave Transmitter
|
||||
case TW_ST_SLA_ACK: // addressed, returned ack
|
||||
case TW_ST_ARB_LOST_SLA_ACK: // arbitration lost, returned ack
|
||||
// enter slave transmitter mode
|
||||
twi_state = TWI_STX;
|
||||
// ready the tx buffer index for iteration
|
||||
twi_txBufferIndex = 0;
|
||||
// set tx buffer length to be zero, to verify if user changes it
|
||||
twi_txBufferLength = 0;
|
||||
// request for txBuffer to be filled and length to be set
|
||||
// note: user must call twi_transmit(bytes, length) to do this
|
||||
twi_onSlaveTransmit();
|
||||
// if they didn't change buffer & length, initialize it
|
||||
if(0 == twi_txBufferLength){
|
||||
twi_txBufferLength = 1;
|
||||
twi_txBuffer[0] = 0x00;
|
||||
}
|
||||
// transmit first byte from buffer, fall
|
||||
case TW_ST_DATA_ACK: // byte sent, ack returned
|
||||
// copy data to output register
|
||||
TWDR = twi_txBuffer[twi_txBufferIndex++];
|
||||
// if there is more to send, ack, otherwise nack
|
||||
if(twi_txBufferIndex < twi_txBufferLength){
|
||||
twi_reply(1);
|
||||
}else{
|
||||
twi_reply(0);
|
||||
}
|
||||
break;
|
||||
case TW_ST_DATA_NACK: // received nack, we are done
|
||||
case TW_ST_LAST_DATA: // received ack, but we are done already!
|
||||
// ack future responses
|
||||
twi_reply(1);
|
||||
// leave slave receiver state
|
||||
twi_state = TWI_READY;
|
||||
break;
|
||||
|
||||
// All
|
||||
case TW_NO_INFO: // no state information
|
||||
break;
|
||||
case TW_BUS_ERROR: // bus error, illegal stop/start
|
||||
twi_error = TW_BUS_ERROR;
|
||||
twi_stop();
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
@ -1,53 +0,0 @@
|
||||
/*
|
||||
twi.h - TWI/I2C library for Wiring & Arduino
|
||||
Copyright (c) 2006 Nicholas Zambetti. All right 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.
|
||||
|
||||
This library is distributed in the hope that it will be useful,
|
||||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||||
Lesser General Public License for more details.
|
||||
|
||||
You should have received a copy of the GNU Lesser General Public
|
||||
License along with this library; if not, write to the Free Software
|
||||
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
||||
*/
|
||||
|
||||
#ifndef twi_h
|
||||
#define twi_h
|
||||
|
||||
#include <inttypes.h>
|
||||
|
||||
//#define ATMEGA8
|
||||
|
||||
#ifndef TWI_FREQ
|
||||
#define TWI_FREQ 100000L
|
||||
#endif
|
||||
|
||||
#ifndef TWI_BUFFER_LENGTH
|
||||
#define TWI_BUFFER_LENGTH 32
|
||||
#endif
|
||||
|
||||
#define TWI_READY 0
|
||||
#define TWI_MRX 1
|
||||
#define TWI_MTX 2
|
||||
#define TWI_SRX 3
|
||||
#define TWI_STX 4
|
||||
|
||||
void twi_init(void);
|
||||
void twi_setAddress(uint8_t);
|
||||
uint8_t twi_readFrom(uint8_t, uint8_t*, uint8_t);
|
||||
uint8_t twi_writeTo(uint8_t, uint8_t*, uint8_t, uint8_t);
|
||||
uint8_t twi_transmit(const uint8_t*, uint8_t);
|
||||
void twi_attachSlaveRxEvent( void (*)(uint8_t*, int) );
|
||||
void twi_attachSlaveTxEvent( void (*)(void) );
|
||||
void twi_reply(uint8_t);
|
||||
void twi_stop(void);
|
||||
void twi_releaseBus(void);
|
||||
|
||||
#endif
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user