[136] | 1 | /*
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[175] | 2 | * TWI/I2C library for Arduino Zero
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| 3 | * Copyright (c) 2015 Arduino LLC. All rights reserved.
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[136] | 4 | *
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| 5 | * This library is free software; you can redistribute it and/or
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| 6 | * modify it under the terms of the GNU Lesser General Public
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| 7 | * License as published by the Free Software Foundation; either
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| 8 | * version 2.1 of the License, or (at your option) any later version.
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| 9 | *
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| 10 | * This library is distributed in the hope that it will be useful,
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| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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| 13 | * Lesser General Public License for more details.
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| 14 | *
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| 15 | * You should have received a copy of the GNU Lesser General Public
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| 16 | * License along with this library; if not, write to the Free Software
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| 17 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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| 18 | */
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| 19 |
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| 20 | extern "C" {
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| 21 | #include <string.h>
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| 22 | }
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| 23 |
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[175] | 24 | #include <Arduino.h>
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| 25 | #include <wiring_private.h>
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| 26 |
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[136] | 27 | #include "Wire.h"
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| 28 |
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[175] | 29 | TwoWire::TwoWire(SERCOM * s, uint8_t pinSDA, uint8_t pinSCL)
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[136] | 30 | {
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[175] | 31 | this->sercom = s;
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| 32 | this->_uc_pinSDA=pinSDA;
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| 33 | this->_uc_pinSCL=pinSCL;
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| 34 | transmissionBegun = false;
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[136] | 35 | }
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| 36 |
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| 37 | void TwoWire::begin(void) {
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[175] | 38 | //Master Mode
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| 39 | sercom->initMasterWIRE(TWI_CLOCK);
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| 40 | sercom->enableWIRE();
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[136] | 41 |
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[175] | 42 | pinPeripheral(_uc_pinSDA, g_APinDescription[_uc_pinSDA].ulPinType);
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| 43 | pinPeripheral(_uc_pinSCL, g_APinDescription[_uc_pinSCL].ulPinType);
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[136] | 44 | }
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| 45 |
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| 46 | void TwoWire::begin(uint8_t address) {
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[175] | 47 | //Slave mode
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| 48 | sercom->initSlaveWIRE(address);
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| 49 | sercom->enableWIRE();
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| 50 |
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| 51 | pinPeripheral(_uc_pinSDA, g_APinDescription[_uc_pinSDA].ulPinType);
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| 52 | pinPeripheral(_uc_pinSCL, g_APinDescription[_uc_pinSCL].ulPinType);
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[136] | 53 | }
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| 54 |
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[175] | 55 | void TwoWire::setClock(uint32_t baudrate) {
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| 56 | sercom->disableWIRE();
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| 57 | sercom->initMasterWIRE(baudrate);
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| 58 | sercom->enableWIRE();
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| 59 | }
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| 60 |
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| 61 | void TwoWire::end() {
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| 62 | sercom->disableWIRE();
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| 63 | }
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| 64 |
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[136] | 65 | uint8_t TwoWire::requestFrom(uint8_t address, size_t quantity, bool stopBit)
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[175] | 66 | {
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[136] | 67 | if(quantity == 0)
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| 68 | {
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| 69 | return 0;
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| 70 | }
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| 71 |
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| 72 | size_t byteRead = 0;
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| 73 |
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| 74 | if(sercom->startTransmissionWIRE(address, WIRE_READ_FLAG))
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| 75 | {
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| 76 | // Read first data
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| 77 | rxBuffer.store_char(sercom->readDataWIRE());
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| 78 |
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| 79 | // Connected to slave
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[175] | 80 | for (byteRead = 1; byteRead < quantity; ++byteRead)
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[136] | 81 | {
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[175] | 82 | sercom->prepareAckBitWIRE(); // Prepare Acknowledge
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| 83 | sercom->prepareCommandBitsWire(WIRE_MASTER_ACT_READ); // Prepare the ACK command for the slave
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| 84 | rxBuffer.store_char(sercom->readDataWIRE()); // Read data and send the ACK
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[136] | 85 | }
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[175] | 86 | sercom->prepareNackBitWIRE(); // Prepare NACK to stop slave transmission
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| 87 | //sercom->readDataWIRE(); // Clear data register to send NACK
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| 88 |
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| 89 | if (stopBit)
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| 90 | {
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| 91 | sercom->prepareCommandBitsWire(WIRE_MASTER_ACT_STOP); // Send Stop
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| 92 | }
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[136] | 93 | }
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| 94 |
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| 95 | return byteRead;
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| 96 | }
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| 97 |
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| 98 | uint8_t TwoWire::requestFrom(uint8_t address, size_t quantity)
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| 99 | {
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[175] | 100 | return requestFrom(address, quantity, true);
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[136] | 101 | }
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| 102 |
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| 103 | void TwoWire::beginTransmission(uint8_t address) {
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[175] | 104 | // save address of target and clear buffer
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| 105 | txAddress = address;
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| 106 | txBuffer.clear();
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[136] | 107 |
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[175] | 108 | transmissionBegun = true;
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[136] | 109 | }
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| 110 |
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| 111 | // Errors:
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[175] | 112 | // 0 : Success
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| 113 | // 1 : Data too long
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| 114 | // 2 : NACK on transmit of address
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| 115 | // 3 : NACK on transmit of data
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| 116 | // 4 : Other error
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[136] | 117 | uint8_t TwoWire::endTransmission(bool stopBit)
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| 118 | {
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[175] | 119 | transmissionBegun = false ;
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[136] | 120 |
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[175] | 121 | // Start I2C transmission
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| 122 | if ( !sercom->startTransmissionWIRE( txAddress, WIRE_WRITE_FLAG ) )
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[136] | 123 | {
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[175] | 124 | sercom->prepareCommandBitsWire(WIRE_MASTER_ACT_STOP);
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| 125 | return 2 ; // Address error
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[136] | 126 | }
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| 127 |
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[175] | 128 | // Send all buffer
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| 129 | while( txBuffer.available() )
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[136] | 130 | {
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[175] | 131 | // Trying to send data
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| 132 | if ( !sercom->sendDataMasterWIRE( txBuffer.read_char() ) )
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[136] | 133 | {
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| 134 | sercom->prepareCommandBitsWire(WIRE_MASTER_ACT_STOP);
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[175] | 135 | return 3 ; // Nack or error
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[136] | 136 | }
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[175] | 137 | }
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| 138 |
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| 139 | if (stopBit)
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| 140 | {
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| 141 | sercom->prepareCommandBitsWire(WIRE_MASTER_ACT_STOP);
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| 142 | }
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[136] | 143 |
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[175] | 144 | return 0;
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[136] | 145 | }
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| 146 |
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| 147 | uint8_t TwoWire::endTransmission()
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| 148 | {
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[175] | 149 | return endTransmission(true);
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[136] | 150 | }
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| 151 |
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| 152 | size_t TwoWire::write(uint8_t ucData)
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| 153 | {
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[175] | 154 | if(sercom->isMasterWIRE())
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| 155 | {
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| 156 | // No writing, without begun transmission or a full buffer
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| 157 | if ( !transmissionBegun || txBuffer.isFull() )
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[136] | 158 | {
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| 159 | return 0 ;
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| 160 | }
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| 161 |
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[175] | 162 | txBuffer.store_char( ucData ) ;
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[136] | 163 |
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[175] | 164 | return 1 ;
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| 165 | }
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| 166 | else
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| 167 | {
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| 168 | if(sercom->sendDataSlaveWIRE( ucData ))
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[136] | 169 | {
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[175] | 170 | return 1;
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[136] | 171 | }
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[175] | 172 | }
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[136] | 173 |
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[175] | 174 | return 0;
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[136] | 175 | }
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| 176 |
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| 177 | size_t TwoWire::write(const uint8_t *data, size_t quantity)
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| 178 | {
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[175] | 179 | //Try to store all data
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| 180 | for(size_t i = 0; i < quantity; ++i)
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| 181 | {
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| 182 | //Return the number of data stored, when the buffer is full (if write return 0)
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| 183 | if(!write(data[i]))
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| 184 | return i;
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| 185 | }
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[136] | 186 |
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[175] | 187 | //All data stored
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| 188 | return quantity;
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[136] | 189 | }
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| 190 |
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| 191 | int TwoWire::available(void)
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| 192 | {
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[175] | 193 | return rxBuffer.available();
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[136] | 194 | }
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| 195 |
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| 196 | int TwoWire::read(void)
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| 197 | {
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[175] | 198 | return rxBuffer.read_char();
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[136] | 199 | }
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| 200 |
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| 201 | int TwoWire::peek(void)
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| 202 | {
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[175] | 203 | return rxBuffer.peek();
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[136] | 204 | }
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| 205 |
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| 206 | void TwoWire::flush(void)
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| 207 | {
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[175] | 208 | // Do nothing, use endTransmission(..) to force
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| 209 | // data transfer.
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[136] | 210 | }
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| 211 |
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| 212 | void TwoWire::onReceive(void(*function)(int))
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| 213 | {
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[175] | 214 | onReceiveCallback = function;
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[136] | 215 | }
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| 216 |
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| 217 | void TwoWire::onRequest(void(*function)(void))
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| 218 | {
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[175] | 219 | onRequestCallback = function;
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[136] | 220 | }
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| 221 |
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| 222 | void TwoWire::onService(void)
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| 223 | {
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[175] | 224 | if ( sercom->isSlaveWIRE() )
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| 225 | {
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| 226 | if(sercom->isStopDetectedWIRE() ||
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| 227 | (sercom->isAddressMatch() && sercom->isRestartDetectedWIRE() && !sercom->isMasterReadOperationWIRE())) //Stop or Restart detected
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| 228 | {
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| 229 | sercom->prepareAckBitWIRE();
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| 230 | sercom->prepareCommandBitsWire(0x03);
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[136] | 231 |
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[175] | 232 | //Calling onReceiveCallback, if exists
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| 233 | if(onReceiveCallback)
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| 234 | {
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| 235 | onReceiveCallback(available());
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| 236 | }
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| 237 |
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| 238 | rxBuffer.clear();
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| 239 | }
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| 240 | else if(sercom->isAddressMatch()) //Address Match
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| 241 | {
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| 242 | sercom->prepareAckBitWIRE();
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| 243 | sercom->prepareCommandBitsWire(0x03);
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[136] | 244 |
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[175] | 245 | if(sercom->isMasterReadOperationWIRE()) //Is a request ?
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| 246 | {
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| 247 | // wait for data ready flag,
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| 248 | // before calling request callback
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| 249 | while(!sercom->isDataReadyWIRE());
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[136] | 250 |
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[175] | 251 | //Calling onRequestCallback, if exists
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| 252 | if(onRequestCallback)
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| 253 | {
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| 254 | onRequestCallback();
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| 255 | }
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| 256 | }
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| 257 | }
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| 258 | else if(sercom->isDataReadyWIRE()) //Received data
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| 259 | {
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| 260 | if (rxBuffer.isFull()) {
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| 261 | sercom->prepareNackBitWIRE();
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| 262 | } else {
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| 263 | //Store data
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| 264 | rxBuffer.store_char(sercom->readDataWIRE());
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[136] | 265 |
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[175] | 266 | sercom->prepareAckBitWIRE();
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| 267 | }
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[136] | 268 |
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[175] | 269 | sercom->prepareCommandBitsWire(0x03);
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| 270 | }
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| 271 | }
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| 272 | }
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[136] | 273 |
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[175] | 274 | #if WIRE_INTERFACES_COUNT > 0
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| 275 | /* In case new variant doesn't define these macros,
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| 276 | * we put here the ones for Arduino Zero.
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| 277 | *
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| 278 | * These values should be different on some variants!
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| 279 | */
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| 280 | #ifndef PERIPH_WIRE
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| 281 | #define PERIPH_WIRE sercom3
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| 282 | #define WIRE_IT_HANDLER SERCOM3_Handler
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| 283 | #endif // PERIPH_WIRE
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| 284 | TwoWire Wire(&PERIPH_WIRE, PIN_WIRE_SDA, PIN_WIRE_SCL);
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[136] | 285 |
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[175] | 286 | void WIRE_IT_HANDLER(void) {
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| 287 | Wire.onService();
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| 288 | }
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| 289 | #endif
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[136] | 290 |
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[175] | 291 | #if WIRE_INTERFACES_COUNT > 1
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| 292 | TwoWire Wire1(&PERIPH_WIRE1, PIN_WIRE1_SDA, PIN_WIRE1_SCL);
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[136] | 293 |
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[175] | 294 | void WIRE1_IT_HANDLER(void) {
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| 295 | Wire1.onService();
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| 296 | }
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| 297 | #endif
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[136] | 298 |
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[175] | 299 | #if WIRE_INTERFACES_COUNT > 2
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| 300 | TwoWire Wire2(&PERIPH_WIRE2, PIN_WIRE2_SDA, PIN_WIRE2_SCL);
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[136] | 301 |
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[175] | 302 | void WIRE2_IT_HANDLER(void) {
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| 303 | Wire2.onService();
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| 304 | }
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| 305 | #endif
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[136] | 306 |
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[175] | 307 | #if WIRE_INTERFACES_COUNT > 3
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| 308 | TwoWire Wire3(&PERIPH_WIRE3, PIN_WIRE3_SDA, PIN_WIRE3_SCL);
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[136] | 309 |
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[175] | 310 | void WIRE3_IT_HANDLER(void) {
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| 311 | Wire3.onService();
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| 312 | }
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| 313 | #endif
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[136] | 314 |
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[175] | 315 | #if WIRE_INTERFACES_COUNT > 4
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| 316 | TwoWire Wire4(&PERIPH_WIRE4, PIN_WIRE4_SDA, PIN_WIRE4_SCL);
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[136] | 317 |
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[175] | 318 | void WIRE4_IT_HANDLER(void) {
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| 319 | Wire4.onService();
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| 320 | }
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| 321 | #endif
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[136] | 322 |
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[175] | 323 | #if WIRE_INTERFACES_COUNT > 5
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| 324 | TwoWire Wire5(&PERIPH_WIRE5, PIN_WIRE5_SDA, PIN_WIRE5_SCL);
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[136] | 325 |
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[175] | 326 | void WIRE5_IT_HANDLER(void) {
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| 327 | Wire5.onService();
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| 328 | }
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| 329 | #endif
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[136] | 330 |
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