Wim Huiskamp
Added support for banked registers
Dependents: Component_Test_Interface FalconWing MX_Spoile_Test Simple_Power_Distribution ... more
MCP23017.cpp@5:5696b886a895, 2012-02-13 (annotated)
- Committer:
- wim
- Date:
- Mon Feb 13 22:14:51 2012 +0000
- Revision:
- 5:5696b886a895
- Parent:
- 4:868db61f5f4e
Who changed what in which revision?
| User | Revision | Line number | New 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 | 1:e2edbd61f4d0 | 6 | * version 0.2 Initial Release |
| wim | 1:e2edbd61f4d0 | 7 | * version 0.3 Cleaned up |
| wim | 3:72da9cd002bd | 8 | * version 0.4 Fixed problem with _read method |
| wim | 4:868db61f5f4e | 9 | * version 0.5 Added support for 'Banked' access to registers |
| wim | 0:1a9288cc0630 | 10 | */ |
| wim | 0:1a9288cc0630 | 11 | |
| wim | 0:1a9288cc0630 | 12 | #include "mbed.h" |
| wim | 0:1a9288cc0630 | 13 | #include "MCP23017.h" |
| wim | 0:1a9288cc0630 | 14 | |
| wim | 1:e2edbd61f4d0 | 15 | /** Create an MCP23017 object connected to the specified I2C object and using the specified deviceAddress |
| wim | 1:e2edbd61f4d0 | 16 | * |
| wim | 1:e2edbd61f4d0 | 17 | * @param I2C &i2c the I2C port to connect to |
| wim | 3:72da9cd002bd | 18 | * @param char deviceAddress the address of the MCP23017 |
| wim | 1:e2edbd61f4d0 | 19 | */ |
| wim | 0:1a9288cc0630 | 20 | MCP23017::MCP23017(I2C &i2c, char deviceAddress) : _i2c(i2c) { |
| wim | 0:1a9288cc0630 | 21 | _writeOpcode = deviceAddress & 0xFE; // low order bit = 0 for write |
| wim | 0:1a9288cc0630 | 22 | _readOpcode = deviceAddress | 0x01; // low order bit = 1 for read |
| wim | 0:1a9288cc0630 | 23 | _init(); |
| wim | 0:1a9288cc0630 | 24 | } |
| wim | 0:1a9288cc0630 | 25 | |
| wim | 1:e2edbd61f4d0 | 26 | /** Read from specified MCP23017 register |
| wim | 1:e2edbd61f4d0 | 27 | * |
| wim | 3:72da9cd002bd | 28 | * @param char address the internal registeraddress of the MCP23017 |
| wim | 1:e2edbd61f4d0 | 29 | * @returns data from register |
| wim | 1:e2edbd61f4d0 | 30 | */ |
| wim | 0:1a9288cc0630 | 31 | char MCP23017::_read(char address) { |
| wim | 0:1a9288cc0630 | 32 | char data[2]; |
| wim | 0:1a9288cc0630 | 33 | |
| wim | 0:1a9288cc0630 | 34 | data[0] = address; |
| wim | 3:72da9cd002bd | 35 | _i2c.write(_writeOpcode, data, 1); // Select Register for reading |
| wim | 3:72da9cd002bd | 36 | _i2c.read(_readOpcode, data, 1); // Read from selected Register |
| wim | 0:1a9288cc0630 | 37 | |
| wim | 3:72da9cd002bd | 38 | return data[0]; |
| wim | 0:1a9288cc0630 | 39 | } |
| wim | 0:1a9288cc0630 | 40 | |
| wim | 0:1a9288cc0630 | 41 | |
| wim | 1:e2edbd61f4d0 | 42 | /** Write to specified MCP23017 register |
| wim | 1:e2edbd61f4d0 | 43 | * |
| wim | 3:72da9cd002bd | 44 | * @param char address the internal registeraddress of the MCP23017 |
| wim | 1:e2edbd61f4d0 | 45 | */ |
| wim | 0:1a9288cc0630 | 46 | void MCP23017::_write(char address, char byte) { |
| wim | 0:1a9288cc0630 | 47 | char data[2]; |
| wim | 0:1a9288cc0630 | 48 | |
| wim | 0:1a9288cc0630 | 49 | data[0] = address; |
| wim | 0:1a9288cc0630 | 50 | data[1] = byte; |
| wim | 0:1a9288cc0630 | 51 | _i2c.write(_writeOpcode, data, 2); // Write data to selected Register |
| wim | 0:1a9288cc0630 | 52 | } |
| wim | 0:1a9288cc0630 | 53 | |
| wim | 0:1a9288cc0630 | 54 | |
| wim | 1:e2edbd61f4d0 | 55 | /** Init MCP23017 |
| wim | 1:e2edbd61f4d0 | 56 | * |
| wim | 1:e2edbd61f4d0 | 57 | * @param |
| wim | 1:e2edbd61f4d0 | 58 | * @returns |
| wim | 1:e2edbd61f4d0 | 59 | */ |
| wim | 0:1a9288cc0630 | 60 | void MCP23017::_init() { |
| wim | 4:868db61f5f4e | 61 | |
| wim | 4:868db61f5f4e | 62 | _bankMode = NOT_BNK; // This may not be true after software reset without hardware reset !!! |
| wim | 4:868db61f5f4e | 63 | |
| wim | 4:868db61f5f4e | 64 | _write(IOCON_AB[_bankMode][PORT_A], (IOCON_BYTE_MODE | IOCON_HAEN )); // Hardware addressing on, no-autoincrement, 16 bit mode (operations toggle between A and B registers) |
| wim | 0:1a9288cc0630 | 65 | |
| wim | 0:1a9288cc0630 | 66 | } |
| wim | 0:1a9288cc0630 | 67 | |
| wim | 1:e2edbd61f4d0 | 68 | /** Set I/O direction of specified MCP23017 Port |
| wim | 1:e2edbd61f4d0 | 69 | * |
| wim | 1:e2edbd61f4d0 | 70 | * @param Port Port address (Port_A or Port_B) |
| wim | 1:e2edbd61f4d0 | 71 | * @param char direction pin direction (0 = output, 1 = input) |
| wim | 1:e2edbd61f4d0 | 72 | */ |
| wim | 0:1a9288cc0630 | 73 | void MCP23017::direction(Port port, char direction) { |
| wim | 4:868db61f5f4e | 74 | _write(IODIR_AB[_bankMode][port], direction); |
| wim | 0:1a9288cc0630 | 75 | } |
| wim | 0:1a9288cc0630 | 76 | |
| wim | 1:e2edbd61f4d0 | 77 | /** Set Pull-Up Resistors on specified MCP23017 Port |
| wim | 1:e2edbd61f4d0 | 78 | * |
| wim | 1:e2edbd61f4d0 | 79 | * @param Port Port address (Port_A or Port_B) |
| wim | 1:e2edbd61f4d0 | 80 | * @param char offOrOn per pin (0 = off, 1 = on) |
| wim | 1:e2edbd61f4d0 | 81 | */ |
| wim | 0:1a9288cc0630 | 82 | void MCP23017::configurePullUps(Port port, char offOrOn) { |
| wim | 4:868db61f5f4e | 83 | |
| wim | 4:868db61f5f4e | 84 | _write(GPPU_AB[_bankMode][port], offOrOn); |
| wim | 0:1a9288cc0630 | 85 | } |
| wim | 0:1a9288cc0630 | 86 | |
| wim | 4:868db61f5f4e | 87 | /** Configere the Banked or Non-Banked mode |
| wim | 4:868db61f5f4e | 88 | * |
| wim | 4:868db61f5f4e | 89 | * @param Bank bankMode |
| wim | 4:868db61f5f4e | 90 | * @param char offOrOn per pin (0 = off, 1 = on) |
| wim | 4:868db61f5f4e | 91 | */ |
| wim | 4:868db61f5f4e | 92 | void MCP23017::configureBanked(Bank bankMode) { |
| wim | 4:868db61f5f4e | 93 | |
| wim | 4:868db61f5f4e | 94 | if (bankMode == NOT_BNK) { |
| wim | 4:868db61f5f4e | 95 | // Non-Banked sequential registers (default POR) |
| wim | 4:868db61f5f4e | 96 | // Hardware addressing on, , no-autoincrement, 16 bit mode (operations do toggle between A and B registers) |
| wim | 4:868db61f5f4e | 97 | _write(IOCON_AB[_bankMode][PORT_A], (IOCON_BYTE_MODE | IOCON_HAEN )); |
| wim | 4:868db61f5f4e | 98 | _bankMode = NOT_BNK; |
| wim | 4:868db61f5f4e | 99 | } |
| wim | 4:868db61f5f4e | 100 | else { |
| wim | 4:868db61f5f4e | 101 | // Banked registers |
| wim | 4:868db61f5f4e | 102 | // Hardware addressing on, no-autoincrement, 8 bit mode |
| wim | 4:868db61f5f4e | 103 | _write(IOCON_AB[_bankMode][PORT_A], (IOCON_BANK | IOCON_BYTE_MODE | IOCON_HAEN )); |
| wim | 4:868db61f5f4e | 104 | _bankMode = BNK; |
| wim | 4:868db61f5f4e | 105 | } |
| wim | 4:868db61f5f4e | 106 | } |
| wim | 4:868db61f5f4e | 107 | |
| wim | 4:868db61f5f4e | 108 | |
| wim | 0:1a9288cc0630 | 109 | void MCP23017::interruptEnable(Port port, char interruptsEnabledMask) { |
| wim | 4:868db61f5f4e | 110 | |
| wim | 4:868db61f5f4e | 111 | _write(GPINTEN_AB[_bankMode][port], interruptsEnabledMask); |
| wim | 4:868db61f5f4e | 112 | |
| wim | 0:1a9288cc0630 | 113 | } |
| wim | 0:1a9288cc0630 | 114 | |
| wim | 0:1a9288cc0630 | 115 | void MCP23017::mirrorInterrupts(bool mirror) { |
| wim | 4:868db61f5f4e | 116 | char iocon = _read(IOCON_AB[_bankMode][PORT_A]); |
| wim | 4:868db61f5f4e | 117 | |
| wim | 4:868db61f5f4e | 118 | if (mirror) { |
| wim | 4:868db61f5f4e | 119 | iocon = iocon | INTERRUPT_MIRROR_BIT; |
| wim | 4:868db61f5f4e | 120 | } |
| wim | 4:868db61f5f4e | 121 | else { |
| wim | 4:868db61f5f4e | 122 | iocon = iocon & ~INTERRUPT_MIRROR_BIT; |
| wim | 4:868db61f5f4e | 123 | } |
| wim | 4:868db61f5f4e | 124 | |
| wim | 4:868db61f5f4e | 125 | _write(IOCON_AB[_bankMode][PORT_A], iocon); |
| wim | 0:1a9288cc0630 | 126 | |
| wim | 0:1a9288cc0630 | 127 | } |
| wim | 0:1a9288cc0630 | 128 | |
| wim | 0:1a9288cc0630 | 129 | void MCP23017::interruptPolarity(Polarity polarity) { |
| wim | 4:868db61f5f4e | 130 | char iocon = _read(IOCON_AB[_bankMode][PORT_A]); |
| wim | 4:868db61f5f4e | 131 | |
| wim | 0:1a9288cc0630 | 132 | if (polarity == ACTIVE_LOW) { |
| wim | 0:1a9288cc0630 | 133 | iocon = iocon & ~INTERRUPT_POLARITY_BIT; |
| wim | 0:1a9288cc0630 | 134 | } else { |
| wim | 0:1a9288cc0630 | 135 | iocon = iocon | INTERRUPT_POLARITY_BIT; |
| wim | 0:1a9288cc0630 | 136 | } |
| wim | 4:868db61f5f4e | 137 | _write(IOCON_AB[_bankMode][PORT_A], iocon); |
| wim | 0:1a9288cc0630 | 138 | } |
| wim | 0:1a9288cc0630 | 139 | |
| wim | 0:1a9288cc0630 | 140 | void MCP23017::defaultValue(Port port, char valuesToCompare) { |
| wim | 4:868db61f5f4e | 141 | |
| wim | 4:868db61f5f4e | 142 | _write(DEFVAL_AB[_bankMode][port], valuesToCompare); |
| wim | 4:868db61f5f4e | 143 | |
| wim | 0:1a9288cc0630 | 144 | } |
| wim | 0:1a9288cc0630 | 145 | |
| wim | 0:1a9288cc0630 | 146 | void MCP23017::interruptControl(Port port, char interruptControlBits) { |
| wim | 4:868db61f5f4e | 147 | |
| wim | 4:868db61f5f4e | 148 | _write(INTCON_AB[_bankMode][port], interruptControlBits); |
| wim | 4:868db61f5f4e | 149 | |
| wim | 0:1a9288cc0630 | 150 | } |
| wim | 0:1a9288cc0630 | 151 | |
| wim | 1:e2edbd61f4d0 | 152 | /** Write to specified MCP23017 Port |
| wim | 1:e2edbd61f4d0 | 153 | * |
| wim | 1:e2edbd61f4d0 | 154 | * @param Port Port address (Port_A or Port_B) |
| wim | 1:e2edbd61f4d0 | 155 | * @param char byte data to write |
| wim | 1:e2edbd61f4d0 | 156 | */ |
| wim | 0:1a9288cc0630 | 157 | void MCP23017::write(Port port, char byte) { |
| wim | 4:868db61f5f4e | 158 | _write(OLAT_AB[_bankMode][port], byte); |
| wim | 0:1a9288cc0630 | 159 | } |
| wim | 0:1a9288cc0630 | 160 | |
| wim | 1:e2edbd61f4d0 | 161 | /** Read from specified MCP23017 Port |
| wim | 1:e2edbd61f4d0 | 162 | * |
| wim | 1:e2edbd61f4d0 | 163 | * @param Port Port address (Port_A or Port_B) |
| wim | 1:e2edbd61f4d0 | 164 | * @returns data from Port |
| wim | 1:e2edbd61f4d0 | 165 | */ |
| wim | 0:1a9288cc0630 | 166 | char MCP23017::read(Port port) { |
| wim | 4:868db61f5f4e | 167 | return _read(GPIO_AB[_bankMode][port]); |
| wim | 0:1a9288cc0630 | 168 | } |
| wim | 0:1a9288cc0630 | 169 |
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Repository details
| Type: | Library |
|---|---|
| Created: | 18 Dec 2010 |
| Imports: | 271 |
| Forks: | 0 |
| Commits: | 6 |
| Dependents: | 8 |
| Dependencies: | 0 |
| Followers: | 11 |
The code in this repository is Apache licensed.
Components
MCP2317 I2C 16 bit I/O expander