Wim Huiskamp / MCP23017

Added support for banked registers

Dependents:   Component_Test_Interface FalconWing MX_Spoile_Test Simple_Power_Distribution ... more

MCP23017.cpp@0:1a9288cc0630, 2010-12-18 (annotated)

Committer:
wim
Date:
Sat Dec 18 18:49:19 2010 +0000
Revision:
0:1a9288cc0630
Child:
1:e2edbd61f4d0
Initial Version

Who changed what in which revision?

UserRevisionLine numberNew contents of line
wim 0:1a9288cc0630 1 /* MCP23017 - drive the Microchip MCP23017 16-bit Port Extender using I2C
wim 0:1a9288cc0630 2 * Copyright (c) 2010 Wim Huiskamp, Romilly Cocking (original version for SPI)
wim 0:1a9288cc0630 3 *
wim 0:1a9288cc0630 4 * Released under the MIT License: http://mbed.org/license/mit
wim 0:1a9288cc0630 5 *
wim 0:1a9288cc0630 6 * version 0.2
wim 0:1a9288cc0630 7 */
wim 0:1a9288cc0630 8
wim 0:1a9288cc0630 9 #include "mbed.h"
wim 0:1a9288cc0630 10 #include "MCP23017.h"
wim 0:1a9288cc0630 11
wim 0:1a9288cc0630 12 MCP23017::MCP23017(I2C &i2c, char deviceAddress) : _i2c(i2c) {
wim 0:1a9288cc0630 13 _writeOpcode = deviceAddress & 0xFE; // low order bit = 0 for write
wim 0:1a9288cc0630 14 _readOpcode = deviceAddress | 0x01; // low order bit = 1 for read
wim 0:1a9288cc0630 15 _init();
wim 0:1a9288cc0630 16 }
wim 0:1a9288cc0630 17
wim 0:1a9288cc0630 18 char MCP23017::_read(char address) {
wim 0:1a9288cc0630 19 char data[2];
wim 0:1a9288cc0630 20 char result;
wim 0:1a9288cc0630 21
wim 0:1a9288cc0630 22 data[0] = address;
wim 0:1a9288cc0630 23 _i2c.write(_writeOpcode, data, 1); // Select Register for reading
wim 0:1a9288cc0630 24 result = _i2c.read(_readOpcode); // Read from selected Register
wim 0:1a9288cc0630 25
wim 0:1a9288cc0630 26 return result;
wim 0:1a9288cc0630 27 }
wim 0:1a9288cc0630 28
wim 0:1a9288cc0630 29
wim 0:1a9288cc0630 30 void MCP23017::_write(char address, char byte) {
wim 0:1a9288cc0630 31 char data[2];
wim 0:1a9288cc0630 32
wim 0:1a9288cc0630 33 data[0] = address;
wim 0:1a9288cc0630 34 data[1] = byte;
wim 0:1a9288cc0630 35 _i2c.write(_writeOpcode, data, 2); // Write data to selected Register
wim 0:1a9288cc0630 36 }
wim 0:1a9288cc0630 37
wim 0:1a9288cc0630 38
wim 0:1a9288cc0630 39 void MCP23017::_init() {
wim 0:1a9288cc0630 40 _write(IOCON, (IOCON_BYTE_MODE | IOCON_HAEN )); // Hardware addressing on, operations toggle between A and B registers
wim 0:1a9288cc0630 41
wim 0:1a9288cc0630 42 }
wim 0:1a9288cc0630 43
wim 0:1a9288cc0630 44 void MCP23017::direction(Port port, char direction) {
wim 0:1a9288cc0630 45 _write(port + IODIRA, direction);
wim 0:1a9288cc0630 46 }
wim 0:1a9288cc0630 47
wim 0:1a9288cc0630 48 void MCP23017::configurePullUps(Port port, char offOrOn) {
wim 0:1a9288cc0630 49 _write(port + GPPUA, offOrOn);
wim 0:1a9288cc0630 50 }
wim 0:1a9288cc0630 51
wim 0:1a9288cc0630 52 void MCP23017::interruptEnable(Port port, char interruptsEnabledMask) {
wim 0:1a9288cc0630 53 _write(port + GPINTENA, interruptsEnabledMask);
wim 0:1a9288cc0630 54 }
wim 0:1a9288cc0630 55
wim 0:1a9288cc0630 56 void MCP23017::mirrorInterrupts(bool mirror) {
wim 0:1a9288cc0630 57 char iocon = _read(IOCON);
wim 0:1a9288cc0630 58 if (mirror) {
wim 0:1a9288cc0630 59 iocon = iocon | INTERRUPT_MIRROR_BIT;
wim 0:1a9288cc0630 60 } else {
wim 0:1a9288cc0630 61 iocon = iocon & ~INTERRUPT_MIRROR_BIT;
wim 0:1a9288cc0630 62 }
wim 0:1a9288cc0630 63 _write(IOCON, iocon);
wim 0:1a9288cc0630 64
wim 0:1a9288cc0630 65 }
wim 0:1a9288cc0630 66
wim 0:1a9288cc0630 67 void MCP23017::interruptPolarity(Polarity polarity) {
wim 0:1a9288cc0630 68 char iocon = _read(IOCON);
wim 0:1a9288cc0630 69 if (polarity == ACTIVE_LOW) {
wim 0:1a9288cc0630 70 iocon = iocon & ~INTERRUPT_POLARITY_BIT;
wim 0:1a9288cc0630 71 } else {
wim 0:1a9288cc0630 72 iocon = iocon | INTERRUPT_POLARITY_BIT;
wim 0:1a9288cc0630 73 }
wim 0:1a9288cc0630 74 _write(IOCON, iocon);
wim 0:1a9288cc0630 75 }
wim 0:1a9288cc0630 76
wim 0:1a9288cc0630 77 void MCP23017::defaultValue(Port port, char valuesToCompare) {
wim 0:1a9288cc0630 78 _write(port + DEFVALA, valuesToCompare);
wim 0:1a9288cc0630 79 }
wim 0:1a9288cc0630 80
wim 0:1a9288cc0630 81 void MCP23017::interruptControl(Port port, char interruptControlBits) {
wim 0:1a9288cc0630 82 _write(port + INTCONA, interruptControlBits);
wim 0:1a9288cc0630 83 }
wim 0:1a9288cc0630 84
wim 0:1a9288cc0630 85 void MCP23017::write(Port port, char byte) {
wim 0:1a9288cc0630 86 _write(port + OLATA, byte);
wim 0:1a9288cc0630 87
wim 0:1a9288cc0630 88 //faster (56 sec for lcd init)
wim 0:1a9288cc0630 89 // char data[2];
wim 0:1a9288cc0630 90 //
wim 0:1a9288cc0630 91 // data[0] = OLATA + port;
wim 0:1a9288cc0630 92 // data[1] = byte;
wim 0:1a9288cc0630 93 // _i2c.write(_writeOpcode, data, 2); // Write data to selected Register
wim 0:1a9288cc0630 94
wim 0:1a9288cc0630 95 //faster 47 sec for complete init
wim 0:1a9288cc0630 96 // _i2c.start();
wim 0:1a9288cc0630 97 // _i2c.write(_writeOpcode); // Select Device
wim 0:1a9288cc0630 98 // _i2c.write(OLATA + port); // Select Register
wim 0:1a9288cc0630 99 // _i2c.write(byte); // Write data to selected Register
wim 0:1a9288cc0630 100 // _i2c.stop();
wim 0:1a9288cc0630 101 }
wim 0:1a9288cc0630 102
wim 0:1a9288cc0630 103
wim 0:1a9288cc0630 104 char MCP23017::read(Port port) {
wim 0:1a9288cc0630 105 return _read(port + GPIOA);
wim 0:1a9288cc0630 106 }
wim 0:1a9288cc0630 107
wim 0:1a9288cc0630 108 // Optimised Databus write operation for Graphics LCD.
wim 0:1a9288cc0630 109 // Port A is used as databus, Port B is used as controlbus.
wim 0:1a9288cc0630 110 //
wim 0:1a9288cc0630 111 void MCP23017::databus_write(char data, char ctrl_1, char ctrl_2, char ctrl_3, char ctrl_4) {
wim 0:1a9288cc0630 112
wim 0:1a9288cc0630 113 _i2c.start();
wim 0:1a9288cc0630 114 _i2c.write(_writeOpcode); // Select Device
wim 0:1a9288cc0630 115 _i2c.write(OLATA); // Select Register A
wim 0:1a9288cc0630 116
wim 0:1a9288cc0630 117 //Remove separate CS Low, to speed up
wim 0:1a9288cc0630 118 // _i2c.write(data); // Write data to Port A Register and Auto-incr to Register B
wim 0:1a9288cc0630 119 // _i2c.write(ctrl_1); // Write control to Port B and Auto-incr to Register A
wim 0:1a9288cc0630 120
wim 0:1a9288cc0630 121 _i2c.write(data); // Write data to Port A Register and Auto-incr to Register B
wim 0:1a9288cc0630 122 _i2c.write(ctrl_2); // Write control to Port B and Auto-incr to Register A
wim 0:1a9288cc0630 123
wim 0:1a9288cc0630 124 _i2c.write(data); // Write data to Port A Register and Auto-incr to Register B
wim 0:1a9288cc0630 125 _i2c.write(ctrl_3); // Write control to Port B and Auto-incr to Register A
wim 0:1a9288cc0630 126
wim 0:1a9288cc0630 127 //Remove separate CS High, to speed up
wim 0:1a9288cc0630 128 // _i2c.write(data); // Write data to Port A Register and Auto-incr to Register B
wim 0:1a9288cc0630 129 // _i2c.write(ctrl_4); // Write control to Port B and Auto-incr to Register A
wim 0:1a9288cc0630 130
wim 0:1a9288cc0630 131 _i2c.stop();
wim 0:1a9288cc0630 132 }