Nurbol Nurdaulet
/
MCP23017
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Dependents: state_machine_modes_1_12_11 state_machine_modes_1_12_11_11h
MCP23017.cpp@0:69c047b34ca6, 2011-11-09 (annotated)
- Committer:
- Nurbol
- Date:
- Wed Nov 09 17:09:31 2011 +0000
- Revision:
- 0:69c047b34ca6
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| Nurbol | 0:69c047b34ca6 | 1 | /* MCP23017 library for Arduino |
| Nurbol | 0:69c047b34ca6 | 2 | Copyright (C) 2009 David Pye <davidmpye@gmail.com |
| Nurbol | 0:69c047b34ca6 | 3 | Modified for use on the MBED ARM platform |
| Nurbol | 0:69c047b34ca6 | 4 | |
| Nurbol | 0:69c047b34ca6 | 5 | This program is free software: you can redistribute it and/or modify |
| Nurbol | 0:69c047b34ca6 | 6 | it under the terms of the GNU General Public License as published by |
| Nurbol | 0:69c047b34ca6 | 7 | the Free Software Foundation, either version 3 of the License, or |
| Nurbol | 0:69c047b34ca6 | 8 | (at your option) any later version. |
| Nurbol | 0:69c047b34ca6 | 9 | |
| Nurbol | 0:69c047b34ca6 | 10 | This program is distributed in the hope that it will be useful, |
| Nurbol | 0:69c047b34ca6 | 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| Nurbol | 0:69c047b34ca6 | 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| Nurbol | 0:69c047b34ca6 | 13 | GNU General Public License for more details. |
| Nurbol | 0:69c047b34ca6 | 14 | |
| Nurbol | 0:69c047b34ca6 | 15 | You should have received a copy of the GNU General Public License |
| Nurbol | 0:69c047b34ca6 | 16 | along with this program. If not, see <http://www.gnu.org/licenses/>. |
| Nurbol | 0:69c047b34ca6 | 17 | */ |
| Nurbol | 0:69c047b34ca6 | 18 | |
| Nurbol | 0:69c047b34ca6 | 19 | #include "MCP23017.h" |
| Nurbol | 0:69c047b34ca6 | 20 | #include "mbed.h" |
| Nurbol | 0:69c047b34ca6 | 21 | |
| Nurbol | 0:69c047b34ca6 | 22 | union { |
| Nurbol | 0:69c047b34ca6 | 23 | uint8_t value8[2]; |
| Nurbol | 0:69c047b34ca6 | 24 | uint16_t value16; |
| Nurbol | 0:69c047b34ca6 | 25 | } tmp_data; |
| Nurbol | 0:69c047b34ca6 | 26 | |
| Nurbol | 0:69c047b34ca6 | 27 | /*----------------------------------------------------------------------------- |
| Nurbol | 0:69c047b34ca6 | 28 | * |
| Nurbol | 0:69c047b34ca6 | 29 | */ |
| Nurbol | 0:69c047b34ca6 | 30 | MCP23017::MCP23017(PinName sda, PinName scl, int i2cAddress) : _i2c(sda, scl) { |
| Nurbol | 0:69c047b34ca6 | 31 | MCP23017_i2cAddress = i2cAddress; |
| Nurbol | 0:69c047b34ca6 | 32 | reset(); // initialise chip to power-on condition |
| Nurbol | 0:69c047b34ca6 | 33 | } |
| Nurbol | 0:69c047b34ca6 | 34 | |
| Nurbol | 0:69c047b34ca6 | 35 | /*----------------------------------------------------------------------------- |
| Nurbol | 0:69c047b34ca6 | 36 | * reset |
| Nurbol | 0:69c047b34ca6 | 37 | * Set configuration (IOCON) and direction(IODIR) registers to initial state |
| Nurbol | 0:69c047b34ca6 | 38 | */ |
| Nurbol | 0:69c047b34ca6 | 39 | void MCP23017::reset() { |
| Nurbol | 0:69c047b34ca6 | 40 | // |
| Nurbol | 0:69c047b34ca6 | 41 | // First make sure that the device is in BANK=0 mode |
| Nurbol | 0:69c047b34ca6 | 42 | // |
| Nurbol | 0:69c047b34ca6 | 43 | writeRegister(0x05, (unsigned char)0x00); |
| Nurbol | 0:69c047b34ca6 | 44 | // |
| Nurbol | 0:69c047b34ca6 | 45 | // set direction registers to inputs |
| Nurbol | 0:69c047b34ca6 | 46 | // |
| Nurbol | 0:69c047b34ca6 | 47 | writeRegister(IODIR, (unsigned short)0xFFFF); |
| Nurbol | 0:69c047b34ca6 | 48 | // |
| Nurbol | 0:69c047b34ca6 | 49 | // set all other registers to zero (last of 10 registers is OLAT) |
| Nurbol | 0:69c047b34ca6 | 50 | // |
| Nurbol | 0:69c047b34ca6 | 51 | for (int reg_addr = 2 ; reg_addr <= OLAT ; reg_addr+=2) { |
| Nurbol | 0:69c047b34ca6 | 52 | writeRegister(reg_addr, (unsigned short)0x0000); |
| Nurbol | 0:69c047b34ca6 | 53 | } |
| Nurbol | 0:69c047b34ca6 | 54 | // |
| Nurbol | 0:69c047b34ca6 | 55 | // Set the shadow registers to power-on state |
| Nurbol | 0:69c047b34ca6 | 56 | // |
| Nurbol | 0:69c047b34ca6 | 57 | shadow_IODIR = 0xFFFF; |
| Nurbol | 0:69c047b34ca6 | 58 | shadow_GPIO = 0; |
| Nurbol | 0:69c047b34ca6 | 59 | shadow_GPPU = 0; |
| Nurbol | 0:69c047b34ca6 | 60 | shadow_IPOL = 0; |
| Nurbol | 0:69c047b34ca6 | 61 | } |
| Nurbol | 0:69c047b34ca6 | 62 | |
| Nurbol | 0:69c047b34ca6 | 63 | /*----------------------------------------------------------------------------- |
| Nurbol | 0:69c047b34ca6 | 64 | * write_bit |
| Nurbol | 0:69c047b34ca6 | 65 | * Write a 1/0 to a single bit of the 16-bit port |
| Nurbol | 0:69c047b34ca6 | 66 | */ |
| Nurbol | 0:69c047b34ca6 | 67 | void MCP23017::write_bit(int value, int bit_number) { |
| Nurbol | 0:69c047b34ca6 | 68 | if (value == 0) { |
| Nurbol | 0:69c047b34ca6 | 69 | shadow_GPIO &= ~(1 << bit_number); |
| Nurbol | 0:69c047b34ca6 | 70 | } else { |
| Nurbol | 0:69c047b34ca6 | 71 | shadow_GPIO |= 1 << bit_number; |
| Nurbol | 0:69c047b34ca6 | 72 | } |
| Nurbol | 0:69c047b34ca6 | 73 | writeRegister(GPIO, (unsigned short)shadow_GPIO); |
| Nurbol | 0:69c047b34ca6 | 74 | } |
| Nurbol | 0:69c047b34ca6 | 75 | |
| Nurbol | 0:69c047b34ca6 | 76 | /*----------------------------------------------------------------------------- |
| Nurbol | 0:69c047b34ca6 | 77 | * Write a combination of bits to the 16-bit port |
| Nurbol | 0:69c047b34ca6 | 78 | */ |
| Nurbol | 0:69c047b34ca6 | 79 | void MCP23017::write_mask(unsigned short data, unsigned short mask) { |
| Nurbol | 0:69c047b34ca6 | 80 | shadow_GPIO = (shadow_GPIO & ~mask) | data; |
| Nurbol | 0:69c047b34ca6 | 81 | writeRegister(GPIO, (unsigned short)shadow_GPIO); |
| Nurbol | 0:69c047b34ca6 | 82 | } |
| Nurbol | 0:69c047b34ca6 | 83 | |
| Nurbol | 0:69c047b34ca6 | 84 | /*----------------------------------------------------------------------------- |
| Nurbol | 0:69c047b34ca6 | 85 | * read_bit |
| Nurbol | 0:69c047b34ca6 | 86 | * Read a single bit from the 16-bit port |
| Nurbol | 0:69c047b34ca6 | 87 | */ |
| Nurbol | 0:69c047b34ca6 | 88 | int MCP23017::read_bit(int bit_number) { |
| Nurbol | 0:69c047b34ca6 | 89 | shadow_GPIO = readRegister(GPIO); |
| Nurbol | 0:69c047b34ca6 | 90 | return ((shadow_GPIO >> bit_number) & 0x0001); |
| Nurbol | 0:69c047b34ca6 | 91 | } |
| Nurbol | 0:69c047b34ca6 | 92 | |
| Nurbol | 0:69c047b34ca6 | 93 | /*----------------------------------------------------------------------------- |
| Nurbol | 0:69c047b34ca6 | 94 | * read_mask |
| Nurbol | 0:69c047b34ca6 | 95 | */ |
| Nurbol | 0:69c047b34ca6 | 96 | int MCP23017::read_mask(unsigned short mask) { |
| Nurbol | 0:69c047b34ca6 | 97 | shadow_GPIO = readRegister(GPIO); |
| Nurbol | 0:69c047b34ca6 | 98 | return (shadow_GPIO & mask); |
| Nurbol | 0:69c047b34ca6 | 99 | } |
| Nurbol | 0:69c047b34ca6 | 100 | |
| Nurbol | 0:69c047b34ca6 | 101 | /*----------------------------------------------------------------------------- |
| Nurbol | 0:69c047b34ca6 | 102 | * Config |
| Nurbol | 0:69c047b34ca6 | 103 | * set direction and pull-up registers |
| Nurbol | 0:69c047b34ca6 | 104 | */ |
| Nurbol | 0:69c047b34ca6 | 105 | void MCP23017::config(unsigned short dir_config, unsigned short pullup_config, unsigned short polarity_config) { |
| Nurbol | 0:69c047b34ca6 | 106 | shadow_IODIR = dir_config; |
| Nurbol | 0:69c047b34ca6 | 107 | writeRegister(IODIR, (unsigned short)shadow_IODIR); |
| Nurbol | 0:69c047b34ca6 | 108 | shadow_GPPU = pullup_config; |
| Nurbol | 0:69c047b34ca6 | 109 | writeRegister(GPPU, (unsigned short)shadow_GPPU); |
| Nurbol | 0:69c047b34ca6 | 110 | shadow_IPOL = polarity_config; |
| Nurbol | 0:69c047b34ca6 | 111 | writeRegister(IPOL, (unsigned short)shadow_IPOL); |
| Nurbol | 0:69c047b34ca6 | 112 | } |
| Nurbol | 0:69c047b34ca6 | 113 | |
| Nurbol | 0:69c047b34ca6 | 114 | /*----------------------------------------------------------------------------- |
| Nurbol | 0:69c047b34ca6 | 115 | * writeRegister |
| Nurbol | 0:69c047b34ca6 | 116 | * write a byte |
| Nurbol | 0:69c047b34ca6 | 117 | */ |
| Nurbol | 0:69c047b34ca6 | 118 | void MCP23017::writeRegister(int regAddress, unsigned char data) { |
| Nurbol | 0:69c047b34ca6 | 119 | char buffer[2]; |
| Nurbol | 0:69c047b34ca6 | 120 | |
| Nurbol | 0:69c047b34ca6 | 121 | buffer[0] = regAddress; |
| Nurbol | 0:69c047b34ca6 | 122 | buffer[1] = data; |
| Nurbol | 0:69c047b34ca6 | 123 | _i2c.write(MCP23017_i2cAddress, buffer, 2); |
| Nurbol | 0:69c047b34ca6 | 124 | } |
| Nurbol | 0:69c047b34ca6 | 125 | |
| Nurbol | 0:69c047b34ca6 | 126 | /*---------------------------------------------------------------------------- |
| Nurbol | 0:69c047b34ca6 | 127 | * write Register |
| Nurbol | 0:69c047b34ca6 | 128 | * write two bytes |
| Nurbol | 0:69c047b34ca6 | 129 | */ |
| Nurbol | 0:69c047b34ca6 | 130 | void MCP23017::writeRegister(int regAddress, unsigned short data) { |
| Nurbol | 0:69c047b34ca6 | 131 | char buffer[3]; |
| Nurbol | 0:69c047b34ca6 | 132 | |
| Nurbol | 0:69c047b34ca6 | 133 | buffer[0] = regAddress; |
| Nurbol | 0:69c047b34ca6 | 134 | tmp_data.value16 = data; |
| Nurbol | 0:69c047b34ca6 | 135 | buffer[1] = tmp_data.value8[0]; |
| Nurbol | 0:69c047b34ca6 | 136 | buffer[2] = tmp_data.value8[1]; |
| Nurbol | 0:69c047b34ca6 | 137 | |
| Nurbol | 0:69c047b34ca6 | 138 | _i2c.write(MCP23017_i2cAddress, buffer, 3); |
| Nurbol | 0:69c047b34ca6 | 139 | } |
| Nurbol | 0:69c047b34ca6 | 140 | |
| Nurbol | 0:69c047b34ca6 | 141 | /*----------------------------------------------------------------------------- |
| Nurbol | 0:69c047b34ca6 | 142 | * readRegister |
| Nurbol | 0:69c047b34ca6 | 143 | */ |
| Nurbol | 0:69c047b34ca6 | 144 | int MCP23017::readRegister(int regAddress) { |
| Nurbol | 0:69c047b34ca6 | 145 | char buffer[2]; |
| Nurbol | 0:69c047b34ca6 | 146 | |
| Nurbol | 0:69c047b34ca6 | 147 | buffer[0] = regAddress; |
| Nurbol | 0:69c047b34ca6 | 148 | _i2c.write(MCP23017_i2cAddress, buffer, 1); |
| Nurbol | 0:69c047b34ca6 | 149 | _i2c.read(MCP23017_i2cAddress, buffer, 2); |
| Nurbol | 0:69c047b34ca6 | 150 | |
| Nurbol | 0:69c047b34ca6 | 151 | return ((int)(buffer[0] + (buffer[1]<<8))); |
| Nurbol | 0:69c047b34ca6 | 152 | } |
| Nurbol | 0:69c047b34ca6 | 153 | |
| Nurbol | 0:69c047b34ca6 | 154 | /*----------------------------------------------------------------------------- |
| Nurbol | 0:69c047b34ca6 | 155 | * pinMode |
| Nurbol | 0:69c047b34ca6 | 156 | */ |
| Nurbol | 0:69c047b34ca6 | 157 | void MCP23017::pinMode(int pin, int mode) { |
| Nurbol | 0:69c047b34ca6 | 158 | if (DIR_INPUT) { |
| Nurbol | 0:69c047b34ca6 | 159 | shadow_IODIR |= 1 << pin; |
| Nurbol | 0:69c047b34ca6 | 160 | } else { |
| Nurbol | 0:69c047b34ca6 | 161 | shadow_IODIR &= ~(1 << pin); |
| Nurbol | 0:69c047b34ca6 | 162 | } |
| Nurbol | 0:69c047b34ca6 | 163 | writeRegister(IODIR, (unsigned short)shadow_IODIR); |
| Nurbol | 0:69c047b34ca6 | 164 | } |
| Nurbol | 0:69c047b34ca6 | 165 | |
| Nurbol | 0:69c047b34ca6 | 166 | /*----------------------------------------------------------------------------- |
| Nurbol | 0:69c047b34ca6 | 167 | * digitalRead |
| Nurbol | 0:69c047b34ca6 | 168 | */ |
| Nurbol | 0:69c047b34ca6 | 169 | int MCP23017::digitalRead(int pin) { |
| Nurbol | 0:69c047b34ca6 | 170 | shadow_GPIO = readRegister(GPIO); |
| Nurbol | 0:69c047b34ca6 | 171 | if ( shadow_GPIO & (1 << pin)) { |
| Nurbol | 0:69c047b34ca6 | 172 | return 1; |
| Nurbol | 0:69c047b34ca6 | 173 | } else { |
| Nurbol | 0:69c047b34ca6 | 174 | return 0; |
| Nurbol | 0:69c047b34ca6 | 175 | } |
| Nurbol | 0:69c047b34ca6 | 176 | } |
| Nurbol | 0:69c047b34ca6 | 177 | |
| Nurbol | 0:69c047b34ca6 | 178 | /*----------------------------------------------------------------------------- |
| Nurbol | 0:69c047b34ca6 | 179 | * digitalWrite |
| Nurbol | 0:69c047b34ca6 | 180 | */ |
| Nurbol | 0:69c047b34ca6 | 181 | void MCP23017::digitalWrite(int pin, int val) { |
| Nurbol | 0:69c047b34ca6 | 182 | //If this pin is an INPUT pin, a write here will |
| Nurbol | 0:69c047b34ca6 | 183 | //enable the internal pullup |
| Nurbol | 0:69c047b34ca6 | 184 | //otherwise, it will set the OUTPUT voltage |
| Nurbol | 0:69c047b34ca6 | 185 | //as appropriate. |
| Nurbol | 0:69c047b34ca6 | 186 | bool isOutput = !(shadow_IODIR & 1<<pin); |
| Nurbol | 0:69c047b34ca6 | 187 | |
| Nurbol | 0:69c047b34ca6 | 188 | if (isOutput) { |
| Nurbol | 0:69c047b34ca6 | 189 | //This is an output pin so just write the value |
| Nurbol | 0:69c047b34ca6 | 190 | if (val) shadow_GPIO |= 1 << pin; |
| Nurbol | 0:69c047b34ca6 | 191 | else shadow_GPIO &= ~(1 << pin); |
| Nurbol | 0:69c047b34ca6 | 192 | writeRegister(GPIO, (unsigned short)shadow_GPIO); |
| Nurbol | 0:69c047b34ca6 | 193 | } else { |
| Nurbol | 0:69c047b34ca6 | 194 | //This is an input pin, so we need to enable the pullup |
| Nurbol | 0:69c047b34ca6 | 195 | if (val) { |
| Nurbol | 0:69c047b34ca6 | 196 | shadow_GPPU |= 1 << pin; |
| Nurbol | 0:69c047b34ca6 | 197 | } else { |
| Nurbol | 0:69c047b34ca6 | 198 | shadow_GPPU &= ~(1 << pin); |
| Nurbol | 0:69c047b34ca6 | 199 | } |
| Nurbol | 0:69c047b34ca6 | 200 | writeRegister(GPPU, (unsigned short)shadow_GPPU); |
| Nurbol | 0:69c047b34ca6 | 201 | } |
| Nurbol | 0:69c047b34ca6 | 202 | } |
| Nurbol | 0:69c047b34ca6 | 203 | |
| Nurbol | 0:69c047b34ca6 | 204 | /*----------------------------------------------------------------------------- |
| Nurbol | 0:69c047b34ca6 | 205 | * digitalWordRead |
| Nurbol | 0:69c047b34ca6 | 206 | */ |
| Nurbol | 0:69c047b34ca6 | 207 | unsigned short MCP23017::digitalWordRead() { |
| Nurbol | 0:69c047b34ca6 | 208 | shadow_GPIO = readRegister(GPIO); |
| Nurbol | 0:69c047b34ca6 | 209 | return shadow_GPIO; |
| Nurbol | 0:69c047b34ca6 | 210 | } |
| Nurbol | 0:69c047b34ca6 | 211 | |
| Nurbol | 0:69c047b34ca6 | 212 | /*----------------------------------------------------------------------------- |
| Nurbol | 0:69c047b34ca6 | 213 | * digitalWordWrite |
| Nurbol | 0:69c047b34ca6 | 214 | */ |
| Nurbol | 0:69c047b34ca6 | 215 | void MCP23017::digitalWordWrite(unsigned short w) { |
| Nurbol | 0:69c047b34ca6 | 216 | shadow_GPIO = w; |
| Nurbol | 0:69c047b34ca6 | 217 | writeRegister(GPIO, (unsigned short)shadow_GPIO); |
| Nurbol | 0:69c047b34ca6 | 218 | } |
| Nurbol | 0:69c047b34ca6 | 219 | |
| Nurbol | 0:69c047b34ca6 | 220 | /*----------------------------------------------------------------------------- |
| Nurbol | 0:69c047b34ca6 | 221 | * inputPolarityMask |
| Nurbol | 0:69c047b34ca6 | 222 | */ |
| Nurbol | 0:69c047b34ca6 | 223 | void MCP23017::inputPolarityMask(unsigned short mask) { |
| Nurbol | 0:69c047b34ca6 | 224 | writeRegister(IPOL, mask); |
| Nurbol | 0:69c047b34ca6 | 225 | } |
| Nurbol | 0:69c047b34ca6 | 226 | |
| Nurbol | 0:69c047b34ca6 | 227 | /*----------------------------------------------------------------------------- |
| Nurbol | 0:69c047b34ca6 | 228 | * inputoutputMask |
| Nurbol | 0:69c047b34ca6 | 229 | */ |
| Nurbol | 0:69c047b34ca6 | 230 | void MCP23017::inputOutputMask(unsigned short mask) { |
| Nurbol | 0:69c047b34ca6 | 231 | shadow_IODIR = mask; |
| Nurbol | 0:69c047b34ca6 | 232 | writeRegister(IODIR, (unsigned short)shadow_IODIR); |
| Nurbol | 0:69c047b34ca6 | 233 | } |
| Nurbol | 0:69c047b34ca6 | 234 | |
| Nurbol | 0:69c047b34ca6 | 235 | /*----------------------------------------------------------------------------- |
| Nurbol | 0:69c047b34ca6 | 236 | * internalPullupMask |
| Nurbol | 0:69c047b34ca6 | 237 | */ |
| Nurbol | 0:69c047b34ca6 | 238 | void MCP23017::internalPullupMask(unsigned short mask) { |
| Nurbol | 0:69c047b34ca6 | 239 | shadow_GPPU = mask; |
| Nurbol | 0:69c047b34ca6 | 240 | writeRegister(GPPU, (unsigned short)shadow_GPPU); |
| Nurbol | 0:69c047b34ca6 | 241 | } |
| Nurbol | 0:69c047b34ca6 | 242 |