Joris Aerts / I2CX

Modified I2C api to work with NRF's dynamic pin asignment.

Dependents:   Seed_Barometer_Sensor_custom_I2C_lib

Note that the only changes are in the constructor. I tried extending the original I2C class, but could not find away to avoid the i2c_init from being called there.

I2CX.cpp@2:9d9fc94594e3, 2014-10-22 (annotated)

Committer:
jaerts
Date:
Wed Oct 22 11:18:05 2014 +0000
Revision:
2:9d9fc94594e3
Parent:
0:3d97d631d8dd 
Reset after changing pins on init

Who changed what in which revision?

UserRevisionLine numberNew contents of line
jaerts 0:3d97d631d8dd 1 /* mbed Microcontroller Library
jaerts 0:3d97d631d8dd 2 * Copyright (c) 2006-2013 ARM Limited
jaerts 0:3d97d631d8dd 3 *
jaerts 0:3d97d631d8dd 4 * Licensed under the Apache License, Version 2.0 (the "License");
jaerts 0:3d97d631d8dd 5 * you may not use this file except in compliance with the License.
jaerts 0:3d97d631d8dd 6 * You may obtain a copy of the License at
jaerts 0:3d97d631d8dd 7 *
jaerts 0:3d97d631d8dd 8 * http://www.apache.org/licenses/LICENSE-2.0
jaerts 0:3d97d631d8dd 9 *
jaerts 0:3d97d631d8dd 10 * Unless required by applicable law or agreed to in writing, software
jaerts 0:3d97d631d8dd 11 * distributed under the License is distributed on an "AS IS" BASIS,
jaerts 0:3d97d631d8dd 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
jaerts 0:3d97d631d8dd 13 * See the License for the specific language governing permissions and
jaerts 0:3d97d631d8dd 14 * limitations under the License.
jaerts 0:3d97d631d8dd 15 */
jaerts 0:3d97d631d8dd 16 #include "I2CX.h"
jaerts 0:3d97d631d8dd 17
jaerts 0:3d97d631d8dd 18 #if DEVICE_I2C
jaerts 0:3d97d631d8dd 19
jaerts 0:3d97d631d8dd 20 namespace mbed {
jaerts 0:3d97d631d8dd 21
jaerts 0:3d97d631d8dd 22 I2CX *I2CX::_owner = NULL;
jaerts 0:3d97d631d8dd 23
jaerts 0:3d97d631d8dd 24 I2CX::I2CX(I2CName peripheral, PinName sda, PinName scl) : _i2c(), _hz(100000) {
jaerts 0:3d97d631d8dd 25
jaerts 0:3d97d631d8dd 26 // Hacky way to get around pin mapping
jaerts 0:3d97d631d8dd 27 if(peripheral == I2C_0) {
jaerts 0:3d97d631d8dd 28 i2c_init(&_i2c, p22, p20);
jaerts 0:3d97d631d8dd 29 }
jaerts 0:3d97d631d8dd 30 else if(peripheral == I2C_1) {
jaerts 0:3d97d631d8dd 31 i2c_init(&_i2c, p13, p15);
jaerts 0:3d97d631d8dd 32 }
jaerts 0:3d97d631d8dd 33 else {
jaerts 0:3d97d631d8dd 34 i2c_init(&_i2c, NC, NC);
jaerts 0:3d97d631d8dd 35 }
jaerts 0:3d97d631d8dd 36
jaerts 0:3d97d631d8dd 37 _i2c.sda = sda;
jaerts 0:3d97d631d8dd 38 _i2c.scl = scl;
jaerts 0:3d97d631d8dd 39
jaerts 2:9d9fc94594e3 40 i2c_reset(&_i2c);
jaerts 2:9d9fc94594e3 41
jaerts 0:3d97d631d8dd 42 // Used to avoid unnecessary frequency updates
jaerts 0:3d97d631d8dd 43 _owner = this;
jaerts 0:3d97d631d8dd 44 }
jaerts 0:3d97d631d8dd 45
jaerts 0:3d97d631d8dd 46 void I2CX::frequency(int hz) {
jaerts 0:3d97d631d8dd 47 _hz = hz;
jaerts 0:3d97d631d8dd 48
jaerts 0:3d97d631d8dd 49 // We want to update the frequency even if we are already the bus owners
jaerts 0:3d97d631d8dd 50 i2c_frequency(&_i2c, _hz);
jaerts 0:3d97d631d8dd 51
jaerts 0:3d97d631d8dd 52 // Updating the frequency of the bus we become the owners of it
jaerts 0:3d97d631d8dd 53 _owner = this;
jaerts 0:3d97d631d8dd 54 }
jaerts 0:3d97d631d8dd 55
jaerts 0:3d97d631d8dd 56 void I2CX::aquire() {
jaerts 0:3d97d631d8dd 57 if (_owner != this) {
jaerts 0:3d97d631d8dd 58 i2c_frequency(&_i2c, _hz);
jaerts 0:3d97d631d8dd 59 _owner = this;
jaerts 0:3d97d631d8dd 60 }
jaerts 0:3d97d631d8dd 61 }
jaerts 0:3d97d631d8dd 62
jaerts 0:3d97d631d8dd 63 // write - Master Transmitter Mode
jaerts 0:3d97d631d8dd 64 int I2CX::write(int address, const char* data, int length, bool repeated) {
jaerts 0:3d97d631d8dd 65 aquire();
jaerts 0:3d97d631d8dd 66
jaerts 0:3d97d631d8dd 67 int stop = (repeated) ? 0 : 1;
jaerts 0:3d97d631d8dd 68 int written = i2c_write(&_i2c, address, data, length, stop);
jaerts 0:3d97d631d8dd 69
jaerts 0:3d97d631d8dd 70 return length != written;
jaerts 0:3d97d631d8dd 71 }
jaerts 0:3d97d631d8dd 72
jaerts 0:3d97d631d8dd 73 int I2CX::write(int data) {
jaerts 0:3d97d631d8dd 74 return i2c_byte_write(&_i2c, data);
jaerts 0:3d97d631d8dd 75 }
jaerts 0:3d97d631d8dd 76
jaerts 0:3d97d631d8dd 77 // read - Master Reciever Mode
jaerts 0:3d97d631d8dd 78 int I2CX::read(int address, char* data, int length, bool repeated) {
jaerts 0:3d97d631d8dd 79 aquire();
jaerts 0:3d97d631d8dd 80
jaerts 0:3d97d631d8dd 81 int stop = (repeated) ? 0 : 1;
jaerts 0:3d97d631d8dd 82 int read = i2c_read(&_i2c, address, data, length, stop);
jaerts 0:3d97d631d8dd 83
jaerts 0:3d97d631d8dd 84 return length != read;
jaerts 0:3d97d631d8dd 85 }
jaerts 0:3d97d631d8dd 86
jaerts 0:3d97d631d8dd 87 int I2CX::read(int ack) {
jaerts 0:3d97d631d8dd 88 if (ack) {
jaerts 0:3d97d631d8dd 89 return i2c_byte_read(&_i2c, 0);
jaerts 0:3d97d631d8dd 90 } else {
jaerts 0:3d97d631d8dd 91 return i2c_byte_read(&_i2c, 1);
jaerts 0:3d97d631d8dd 92 }
jaerts 0:3d97d631d8dd 93 }
jaerts 0:3d97d631d8dd 94
jaerts 0:3d97d631d8dd 95 void I2CX::start(void) {
jaerts 0:3d97d631d8dd 96 i2c_start(&_i2c);
jaerts 0:3d97d631d8dd 97 }
jaerts 0:3d97d631d8dd 98
jaerts 0:3d97d631d8dd 99 void I2CX::stop(void) {
jaerts 0:3d97d631d8dd 100 i2c_stop(&_i2c);
jaerts 0:3d97d631d8dd 101 }
jaerts 0:3d97d631d8dd 102
jaerts 0:3d97d631d8dd 103 } // namespace mbed
jaerts 0:3d97d631d8dd 104
jaerts 0:3d97d631d8dd 105 #endif