Merge pull request #8355 from tcm0116/2.0.x-TwoWire
[2.0.x] Master-only TwoWire (I2C) class for LPC17682.0.x
Scott Lahteine
7 years ago
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GitHub
commit
45cfb16424
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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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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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#ifdef TARGET_LPC1768
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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 <lpc17xx_i2c.h>
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#include <lpc17xx_pinsel.h>
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#include <lpc17xx_libcfg_default.h>
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}
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#include "Wire.h"
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#define USEDI2CDEV_M 1
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#if (USEDI2CDEV_M == 0)
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#define I2CDEV_M LPC_I2C0
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#elif (USEDI2CDEV_M == 1)
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#define I2CDEV_M LPC_I2C1
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#elif (USEDI2CDEV_M == 2)
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#define I2CDEV_M LPC_I2C2
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#else
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#error "Master I2C device not defined!"
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#endif
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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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// Constructors ////////////////////////////////////////////////////////////////
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TwoWire::TwoWire() {
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}
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// Public Methods //////////////////////////////////////////////////////////////
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void TwoWire::begin(void) {
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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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/*
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* Init I2C pin connect
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*/
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PINSEL_CFG_Type PinCfg;
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PinCfg.OpenDrain = 0;
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PinCfg.Pinmode = 0;
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#if ((USEDI2CDEV_M == 0))
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PinCfg.Funcnum = 1;
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PinCfg.Pinnum = 27;
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PinCfg.Portnum = 0;
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PINSEL_ConfigPin(&PinCfg); // SDA0 / D57 AUX-1
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PinCfg.Pinnum = 28;
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PINSEL_ConfigPin(&PinCfg); // SCL0 / D58 AUX-1
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#endif
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#if ((USEDI2CDEV_M == 1))
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PinCfg.Funcnum = 3;
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PinCfg.Pinnum = 0;
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PinCfg.Portnum = 0;
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PINSEL_ConfigPin(&PinCfg); // SDA1 / D20 SCA
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PinCfg.Pinnum = 1;
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PINSEL_ConfigPin(&PinCfg); // SCL1 / D21 SCL
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#endif
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#if ((USEDI2CDEV_M == 2))
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PinCfg.Funcnum = 2;
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PinCfg.Pinnum = 10;
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PinCfg.Portnum = 0;
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PINSEL_ConfigPin(&PinCfg); // SDA2 / D38 X_ENABLE_PIN
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PinCfg.Pinnum = 11;
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PINSEL_ConfigPin(&PinCfg); // SCL2 / D55 X_DIR_PIN
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#endif
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// Initialize I2C peripheral
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I2C_Init(I2CDEV_M, 100000);
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// Enable Master I2C operation
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I2C_Cmd(I2CDEV_M, I2C_MASTER_MODE, ENABLE);
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}
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uint8_t TwoWire::requestFrom(uint8_t address, uint8_t quantity) {
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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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I2C_M_SETUP_Type transferMCfg;
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transferMCfg.sl_addr7bit = address >> 1; // not sure about the right shift
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transferMCfg.tx_data = NULL;
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transferMCfg.tx_length = 0;
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transferMCfg.rx_data = rxBuffer;
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transferMCfg.rx_length = quantity;
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transferMCfg.retransmissions_max = 3;
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I2C_MasterTransferData(I2CDEV_M, &transferMCfg, I2C_TRANSFER_POLLING);
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// set rx buffer iterator vars
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rxBufferIndex = 0;
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rxBufferLength = transferMCfg.rx_count;
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return transferMCfg.rx_count;
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}
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uint8_t TwoWire::requestFrom(int address, int quantity) {
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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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// 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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beginTransmission((uint8_t)address);
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}
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uint8_t TwoWire::endTransmission(void) {
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// transmit buffer (blocking)
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I2C_M_SETUP_Type transferMCfg;
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transferMCfg.sl_addr7bit = txAddress >> 1; // not sure about the right shift
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transferMCfg.tx_data = txBuffer;
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transferMCfg.tx_length = txBufferLength;
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transferMCfg.rx_data = NULL;
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transferMCfg.rx_length = 0;
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transferMCfg.retransmissions_max = 3;
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Status status = I2C_MasterTransferData(I2CDEV_M, &transferMCfg, I2C_TRANSFER_POLLING);
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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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if (status == SUCCESS)
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return 0; // success
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else
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return 4; // other error
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}
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// must be called after beginTransmission(address)
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size_t TwoWire::write(uint8_t data) {
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if (transmitting) {
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// don't bother if buffer is full
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if (txBufferLength >= BUFFER_LENGTH) {
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return 0;
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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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}
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return 1;
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}
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// must be called after beginTransmission(address)
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size_t TwoWire::write(const uint8_t *data, size_t quantity) {
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size_t sent = 0;
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if (transmitting)
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for(sent = 0; sent < quantity; ++sent)
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if (!write(data[sent]))
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break;
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return sent;
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}
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// must be called after requestFrom(address, numBytes)
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int TwoWire::available(void) {
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return rxBufferLength - rxBufferIndex;
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}
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// must be called after requestFrom(address, numBytes)
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int TwoWire::read(void) {
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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 after requestFrom(address, numBytes)
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int TwoWire::peek(void) {
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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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// Preinstantiate Objects //////////////////////////////////////////////////////
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TwoWire Wire = TwoWire();
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#endif // TARGET_LPC1768
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