Basic library of routines to interface to a Microchip MCP23017 16-bit I/O expander using an I2C interface.
Dependents: acd52832_beep_buzzer_ints
Fork of MCP23017 by
MCP23017.cpp@14:2e65b7f39273, 2016-09-23 (annotated)
- Committer:
- jurica238814
- Date:
- Fri Sep 23 12:12:24 2016 +0000
- Revision:
- 14:2e65b7f39273
- Parent:
- 12:6d9d2b277f26
IO expander ints done.
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
jimherd | 0:a6a5d942b58f | 1 | /* MCP23017 library for Arduino |
jimherd | 0:a6a5d942b58f | 2 | Copyright (C) 2009 David Pye <davidmpye@gmail.com |
jimherd | 12:6d9d2b277f26 | 3 | Modified for use on the MBED ARM platform |
jimherd | 0:a6a5d942b58f | 4 | |
jimherd | 0:a6a5d942b58f | 5 | This program is free software: you can redistribute it and/or modify |
jimherd | 0:a6a5d942b58f | 6 | it under the terms of the GNU General Public License as published by |
jimherd | 0:a6a5d942b58f | 7 | the Free Software Foundation, either version 3 of the License, or |
jimherd | 0:a6a5d942b58f | 8 | (at your option) any later version. |
jimherd | 0:a6a5d942b58f | 9 | |
jimherd | 0:a6a5d942b58f | 10 | This program is distributed in the hope that it will be useful, |
jimherd | 0:a6a5d942b58f | 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
jimherd | 0:a6a5d942b58f | 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
jimherd | 0:a6a5d942b58f | 13 | GNU General Public License for more details. |
jimherd | 0:a6a5d942b58f | 14 | |
jimherd | 0:a6a5d942b58f | 15 | You should have received a copy of the GNU General Public License |
jimherd | 0:a6a5d942b58f | 16 | along with this program. If not, see <http://www.gnu.org/licenses/>. |
jimherd | 0:a6a5d942b58f | 17 | */ |
jimherd | 4:32fd6ee97dff | 18 | |
jimherd | 4:32fd6ee97dff | 19 | #include "MCP23017.h" |
jimherd | 2:2a17f52c550a | 20 | #include "mbed.h" |
jimherd | 0:a6a5d942b58f | 21 | |
jurica238814 | 14:2e65b7f39273 | 22 | bool interrupt = 0; |
jurica238814 | 14:2e65b7f39273 | 23 | |
jurica238814 | 14:2e65b7f39273 | 24 | void setInt(){ |
jurica238814 | 14:2e65b7f39273 | 25 | interrupt = 1; |
jurica238814 | 14:2e65b7f39273 | 26 | } |
jurica238814 | 14:2e65b7f39273 | 27 | void clearInt(){ |
jurica238814 | 14:2e65b7f39273 | 28 | interrupt = 0; |
jurica238814 | 14:2e65b7f39273 | 29 | } |
jurica238814 | 14:2e65b7f39273 | 30 | bool getInt(){ |
jurica238814 | 14:2e65b7f39273 | 31 | return interrupt; |
jurica238814 | 14:2e65b7f39273 | 32 | } |
jurica238814 | 14:2e65b7f39273 | 33 | |
jimherd | 0:a6a5d942b58f | 34 | union { |
jimherd | 0:a6a5d942b58f | 35 | uint8_t value8[2]; |
jimherd | 0:a6a5d942b58f | 36 | uint16_t value16; |
jimherd | 0:a6a5d942b58f | 37 | } tmp_data; |
jimherd | 0:a6a5d942b58f | 38 | |
jimherd | 12:6d9d2b277f26 | 39 | /*----------------------------------------------------------------------------- |
jimherd | 0:a6a5d942b58f | 40 | * |
jimherd | 0:a6a5d942b58f | 41 | */ |
jimherd | 0:a6a5d942b58f | 42 | MCP23017::MCP23017(PinName sda, PinName scl, int i2cAddress) : _i2c(sda, scl) { |
jimherd | 0:a6a5d942b58f | 43 | MCP23017_i2cAddress = i2cAddress; |
jimherd | 0:a6a5d942b58f | 44 | reset(); // initialise chip to power-on condition |
jimherd | 0:a6a5d942b58f | 45 | } |
jimherd | 0:a6a5d942b58f | 46 | |
jimherd | 12:6d9d2b277f26 | 47 | /*----------------------------------------------------------------------------- |
jimherd | 0:a6a5d942b58f | 48 | * reset |
jimherd | 0:a6a5d942b58f | 49 | * Set configuration (IOCON) and direction(IODIR) registers to initial state |
jimherd | 0:a6a5d942b58f | 50 | */ |
jimherd | 0:a6a5d942b58f | 51 | void MCP23017::reset() { |
jimherd | 0:a6a5d942b58f | 52 | // |
jimherd | 0:a6a5d942b58f | 53 | // First make sure that the device is in BANK=0 mode |
jimherd | 0:a6a5d942b58f | 54 | // |
jimherd | 0:a6a5d942b58f | 55 | writeRegister(0x05, (unsigned char)0x00); |
jimherd | 0:a6a5d942b58f | 56 | // |
jimherd | 0:a6a5d942b58f | 57 | // set direction registers to inputs |
jimherd | 0:a6a5d942b58f | 58 | // |
jimherd | 0:a6a5d942b58f | 59 | writeRegister(IODIR, (unsigned short)0xFFFF); |
jimherd | 0:a6a5d942b58f | 60 | // |
jimherd | 9:e08c29541bc4 | 61 | // set all other registers to zero (last of 10 registers is OLAT) |
jimherd | 0:a6a5d942b58f | 62 | // |
jimherd | 0:a6a5d942b58f | 63 | for (int reg_addr = 2 ; reg_addr <= OLAT ; reg_addr+=2) { |
jimherd | 0:a6a5d942b58f | 64 | writeRegister(reg_addr, (unsigned short)0x0000); |
jimherd | 0:a6a5d942b58f | 65 | } |
jimherd | 0:a6a5d942b58f | 66 | // |
jimherd | 0:a6a5d942b58f | 67 | // Set the shadow registers to power-on state |
jimherd | 0:a6a5d942b58f | 68 | // |
jimherd | 0:a6a5d942b58f | 69 | shadow_IODIR = 0xFFFF; |
jimherd | 0:a6a5d942b58f | 70 | shadow_GPIO = 0; |
jimherd | 0:a6a5d942b58f | 71 | shadow_GPPU = 0; |
jimherd | 0:a6a5d942b58f | 72 | shadow_IPOL = 0; |
jimherd | 0:a6a5d942b58f | 73 | } |
jimherd | 0:a6a5d942b58f | 74 | |
jimherd | 12:6d9d2b277f26 | 75 | /*----------------------------------------------------------------------------- |
jimherd | 0:a6a5d942b58f | 76 | * write_bit |
jimherd | 0:a6a5d942b58f | 77 | * Write a 1/0 to a single bit of the 16-bit port |
jimherd | 0:a6a5d942b58f | 78 | */ |
jimherd | 0:a6a5d942b58f | 79 | void MCP23017::write_bit(int value, int bit_number) { |
jimherd | 0:a6a5d942b58f | 80 | if (value == 0) { |
jimherd | 0:a6a5d942b58f | 81 | shadow_GPIO &= ~(1 << bit_number); |
jimherd | 0:a6a5d942b58f | 82 | } else { |
jimherd | 0:a6a5d942b58f | 83 | shadow_GPIO |= 1 << bit_number; |
jimherd | 0:a6a5d942b58f | 84 | } |
jimherd | 0:a6a5d942b58f | 85 | writeRegister(GPIO, (unsigned short)shadow_GPIO); |
jimherd | 0:a6a5d942b58f | 86 | } |
jimherd | 0:a6a5d942b58f | 87 | |
jimherd | 12:6d9d2b277f26 | 88 | /*----------------------------------------------------------------------------- |
jimherd | 0:a6a5d942b58f | 89 | * Write a combination of bits to the 16-bit port |
jimherd | 0:a6a5d942b58f | 90 | */ |
jimherd | 0:a6a5d942b58f | 91 | void MCP23017::write_mask(unsigned short data, unsigned short mask) { |
jimherd | 0:a6a5d942b58f | 92 | shadow_GPIO = (shadow_GPIO & ~mask) | data; |
jimherd | 0:a6a5d942b58f | 93 | writeRegister(GPIO, (unsigned short)shadow_GPIO); |
jimherd | 0:a6a5d942b58f | 94 | } |
jimherd | 0:a6a5d942b58f | 95 | |
jimherd | 12:6d9d2b277f26 | 96 | /*----------------------------------------------------------------------------- |
jimherd | 0:a6a5d942b58f | 97 | * read_bit |
jimherd | 0:a6a5d942b58f | 98 | * Read a single bit from the 16-bit port |
jimherd | 0:a6a5d942b58f | 99 | */ |
jimherd | 0:a6a5d942b58f | 100 | int MCP23017::read_bit(int bit_number) { |
jimherd | 0:a6a5d942b58f | 101 | shadow_GPIO = readRegister(GPIO); |
jimherd | 0:a6a5d942b58f | 102 | return ((shadow_GPIO >> bit_number) & 0x0001); |
jimherd | 0:a6a5d942b58f | 103 | } |
jimherd | 0:a6a5d942b58f | 104 | |
jimherd | 12:6d9d2b277f26 | 105 | /*----------------------------------------------------------------------------- |
jimherd | 0:a6a5d942b58f | 106 | * read_mask |
jimherd | 0:a6a5d942b58f | 107 | */ |
jimherd | 0:a6a5d942b58f | 108 | int MCP23017::read_mask(unsigned short mask) { |
jimherd | 0:a6a5d942b58f | 109 | shadow_GPIO = readRegister(GPIO); |
jimherd | 0:a6a5d942b58f | 110 | return (shadow_GPIO & mask); |
jimherd | 0:a6a5d942b58f | 111 | } |
jimherd | 0:a6a5d942b58f | 112 | |
jimherd | 12:6d9d2b277f26 | 113 | /*----------------------------------------------------------------------------- |
jimherd | 0:a6a5d942b58f | 114 | * Config |
jimherd | 0:a6a5d942b58f | 115 | * set direction and pull-up registers |
jimherd | 0:a6a5d942b58f | 116 | */ |
jimherd | 0:a6a5d942b58f | 117 | void MCP23017::config(unsigned short dir_config, unsigned short pullup_config, unsigned short polarity_config) { |
jimherd | 0:a6a5d942b58f | 118 | shadow_IODIR = dir_config; |
jimherd | 0:a6a5d942b58f | 119 | writeRegister(IODIR, (unsigned short)shadow_IODIR); |
jimherd | 0:a6a5d942b58f | 120 | shadow_GPPU = pullup_config; |
jimherd | 0:a6a5d942b58f | 121 | writeRegister(GPPU, (unsigned short)shadow_GPPU); |
jimherd | 0:a6a5d942b58f | 122 | shadow_IPOL = polarity_config; |
jimherd | 0:a6a5d942b58f | 123 | writeRegister(IPOL, (unsigned short)shadow_IPOL); |
jimherd | 0:a6a5d942b58f | 124 | } |
jimherd | 0:a6a5d942b58f | 125 | |
jimherd | 12:6d9d2b277f26 | 126 | /*----------------------------------------------------------------------------- |
jimherd | 12:6d9d2b277f26 | 127 | * writeRegister |
jimherd | 12:6d9d2b277f26 | 128 | * write a byte |
jimherd | 12:6d9d2b277f26 | 129 | */ |
jimherd | 12:6d9d2b277f26 | 130 | void MCP23017::writeRegister(int regAddress, unsigned char data) { |
jimherd | 12:6d9d2b277f26 | 131 | char buffer[2]; |
jimherd | 12:6d9d2b277f26 | 132 | |
jimherd | 12:6d9d2b277f26 | 133 | buffer[0] = regAddress; |
jimherd | 12:6d9d2b277f26 | 134 | buffer[1] = data; |
jimherd | 12:6d9d2b277f26 | 135 | _i2c.write(MCP23017_i2cAddress, buffer, 2); |
jimherd | 12:6d9d2b277f26 | 136 | } |
jimherd | 12:6d9d2b277f26 | 137 | |
jimherd | 12:6d9d2b277f26 | 138 | /*---------------------------------------------------------------------------- |
jimherd | 12:6d9d2b277f26 | 139 | * write Register |
jimherd | 12:6d9d2b277f26 | 140 | * write two bytes |
jimherd | 12:6d9d2b277f26 | 141 | */ |
jimherd | 12:6d9d2b277f26 | 142 | void MCP23017::writeRegister(int regAddress, unsigned short data) { |
jimherd | 12:6d9d2b277f26 | 143 | char buffer[3]; |
jimherd | 12:6d9d2b277f26 | 144 | |
jimherd | 12:6d9d2b277f26 | 145 | buffer[0] = regAddress; |
jimherd | 12:6d9d2b277f26 | 146 | tmp_data.value16 = data; |
jimherd | 12:6d9d2b277f26 | 147 | buffer[1] = tmp_data.value8[0]; |
jimherd | 12:6d9d2b277f26 | 148 | buffer[2] = tmp_data.value8[1]; |
jimherd | 12:6d9d2b277f26 | 149 | |
jimherd | 12:6d9d2b277f26 | 150 | _i2c.write(MCP23017_i2cAddress, buffer, 3); |
jimherd | 12:6d9d2b277f26 | 151 | } |
jimherd | 12:6d9d2b277f26 | 152 | |
jimherd | 12:6d9d2b277f26 | 153 | /*----------------------------------------------------------------------------- |
jimherd | 12:6d9d2b277f26 | 154 | * readRegister |
jimherd | 12:6d9d2b277f26 | 155 | */ |
jimherd | 12:6d9d2b277f26 | 156 | int MCP23017::readRegister(int regAddress) { |
jimherd | 12:6d9d2b277f26 | 157 | char buffer[2]; |
jimherd | 12:6d9d2b277f26 | 158 | |
jimherd | 12:6d9d2b277f26 | 159 | buffer[0] = regAddress; |
jimherd | 12:6d9d2b277f26 | 160 | _i2c.write(MCP23017_i2cAddress, buffer, 1); |
jimherd | 12:6d9d2b277f26 | 161 | _i2c.read(MCP23017_i2cAddress, buffer, 2); |
jimherd | 12:6d9d2b277f26 | 162 | |
jimherd | 12:6d9d2b277f26 | 163 | return ((int)(buffer[0] + (buffer[1]<<8))); |
jimherd | 12:6d9d2b277f26 | 164 | } |
jimherd | 12:6d9d2b277f26 | 165 | |
jimherd | 12:6d9d2b277f26 | 166 | /*----------------------------------------------------------------------------- |
jimherd | 12:6d9d2b277f26 | 167 | * pinMode |
jimherd | 12:6d9d2b277f26 | 168 | */ |
jimherd | 12:6d9d2b277f26 | 169 | void MCP23017::pinMode(int pin, int mode) { |
jimherd | 12:6d9d2b277f26 | 170 | if (DIR_INPUT) { |
jimherd | 12:6d9d2b277f26 | 171 | shadow_IODIR |= 1 << pin; |
jimherd | 12:6d9d2b277f26 | 172 | } else { |
jimherd | 12:6d9d2b277f26 | 173 | shadow_IODIR &= ~(1 << pin); |
jimherd | 12:6d9d2b277f26 | 174 | } |
jimherd | 12:6d9d2b277f26 | 175 | writeRegister(IODIR, (unsigned short)shadow_IODIR); |
jimherd | 12:6d9d2b277f26 | 176 | } |
jimherd | 12:6d9d2b277f26 | 177 | |
jimherd | 12:6d9d2b277f26 | 178 | /*----------------------------------------------------------------------------- |
jimherd | 12:6d9d2b277f26 | 179 | * digitalRead |
jimherd | 12:6d9d2b277f26 | 180 | */ |
jimherd | 12:6d9d2b277f26 | 181 | int MCP23017::digitalRead(int pin) { |
jimherd | 12:6d9d2b277f26 | 182 | shadow_GPIO = readRegister(GPIO); |
jimherd | 12:6d9d2b277f26 | 183 | if ( shadow_GPIO & (1 << pin)) { |
jimherd | 12:6d9d2b277f26 | 184 | return 1; |
jimherd | 12:6d9d2b277f26 | 185 | } else { |
jimherd | 12:6d9d2b277f26 | 186 | return 0; |
jimherd | 12:6d9d2b277f26 | 187 | } |
jimherd | 12:6d9d2b277f26 | 188 | } |
jimherd | 12:6d9d2b277f26 | 189 | |
jimherd | 12:6d9d2b277f26 | 190 | /*----------------------------------------------------------------------------- |
jimherd | 0:a6a5d942b58f | 191 | * digitalWrite |
jimherd | 0:a6a5d942b58f | 192 | */ |
jimherd | 0:a6a5d942b58f | 193 | void MCP23017::digitalWrite(int pin, int val) { |
jimherd | 0:a6a5d942b58f | 194 | //If this pin is an INPUT pin, a write here will |
jimherd | 0:a6a5d942b58f | 195 | //enable the internal pullup |
jimherd | 0:a6a5d942b58f | 196 | //otherwise, it will set the OUTPUT voltage |
jimherd | 0:a6a5d942b58f | 197 | //as appropriate. |
jimherd | 0:a6a5d942b58f | 198 | bool isOutput = !(shadow_IODIR & 1<<pin); |
jimherd | 0:a6a5d942b58f | 199 | |
jimherd | 0:a6a5d942b58f | 200 | if (isOutput) { |
jimherd | 0:a6a5d942b58f | 201 | //This is an output pin so just write the value |
jimherd | 0:a6a5d942b58f | 202 | if (val) shadow_GPIO |= 1 << pin; |
jimherd | 0:a6a5d942b58f | 203 | else shadow_GPIO &= ~(1 << pin); |
jimherd | 0:a6a5d942b58f | 204 | writeRegister(GPIO, (unsigned short)shadow_GPIO); |
jimherd | 0:a6a5d942b58f | 205 | } else { |
jimherd | 0:a6a5d942b58f | 206 | //This is an input pin, so we need to enable the pullup |
jimherd | 0:a6a5d942b58f | 207 | if (val) { |
jimherd | 0:a6a5d942b58f | 208 | shadow_GPPU |= 1 << pin; |
jimherd | 0:a6a5d942b58f | 209 | } else { |
jimherd | 0:a6a5d942b58f | 210 | shadow_GPPU &= ~(1 << pin); |
jimherd | 0:a6a5d942b58f | 211 | } |
jimherd | 0:a6a5d942b58f | 212 | writeRegister(GPPU, (unsigned short)shadow_GPPU); |
jimherd | 0:a6a5d942b58f | 213 | } |
jimherd | 0:a6a5d942b58f | 214 | } |
jimherd | 0:a6a5d942b58f | 215 | |
jimherd | 12:6d9d2b277f26 | 216 | /*----------------------------------------------------------------------------- |
jimherd | 0:a6a5d942b58f | 217 | * digitalWordRead |
jimherd | 0:a6a5d942b58f | 218 | */ |
jimherd | 0:a6a5d942b58f | 219 | unsigned short MCP23017::digitalWordRead() { |
jimherd | 0:a6a5d942b58f | 220 | shadow_GPIO = readRegister(GPIO); |
jimherd | 0:a6a5d942b58f | 221 | return shadow_GPIO; |
jimherd | 0:a6a5d942b58f | 222 | } |
jimherd | 0:a6a5d942b58f | 223 | |
jimherd | 12:6d9d2b277f26 | 224 | /*----------------------------------------------------------------------------- |
jimherd | 0:a6a5d942b58f | 225 | * digitalWordWrite |
jimherd | 0:a6a5d942b58f | 226 | */ |
jimherd | 0:a6a5d942b58f | 227 | void MCP23017::digitalWordWrite(unsigned short w) { |
jimherd | 0:a6a5d942b58f | 228 | shadow_GPIO = w; |
jimherd | 0:a6a5d942b58f | 229 | writeRegister(GPIO, (unsigned short)shadow_GPIO); |
jimherd | 0:a6a5d942b58f | 230 | } |
jimherd | 0:a6a5d942b58f | 231 | |
jimherd | 12:6d9d2b277f26 | 232 | /*----------------------------------------------------------------------------- |
jimherd | 0:a6a5d942b58f | 233 | * inputPolarityMask |
jimherd | 0:a6a5d942b58f | 234 | */ |
jimherd | 0:a6a5d942b58f | 235 | void MCP23017::inputPolarityMask(unsigned short mask) { |
jimherd | 0:a6a5d942b58f | 236 | writeRegister(IPOL, mask); |
jimherd | 0:a6a5d942b58f | 237 | } |
jimherd | 0:a6a5d942b58f | 238 | |
jimherd | 12:6d9d2b277f26 | 239 | /*----------------------------------------------------------------------------- |
jimherd | 0:a6a5d942b58f | 240 | * inputoutputMask |
jimherd | 0:a6a5d942b58f | 241 | */ |
jimherd | 0:a6a5d942b58f | 242 | void MCP23017::inputOutputMask(unsigned short mask) { |
jimherd | 0:a6a5d942b58f | 243 | shadow_IODIR = mask; |
jimherd | 0:a6a5d942b58f | 244 | writeRegister(IODIR, (unsigned short)shadow_IODIR); |
jimherd | 0:a6a5d942b58f | 245 | } |
jimherd | 0:a6a5d942b58f | 246 | |
jimherd | 12:6d9d2b277f26 | 247 | /*----------------------------------------------------------------------------- |
jimherd | 0:a6a5d942b58f | 248 | * internalPullupMask |
jimherd | 0:a6a5d942b58f | 249 | */ |
jimherd | 0:a6a5d942b58f | 250 | void MCP23017::internalPullupMask(unsigned short mask) { |
jimherd | 0:a6a5d942b58f | 251 | shadow_GPPU = mask; |
jimherd | 0:a6a5d942b58f | 252 | writeRegister(GPPU, (unsigned short)shadow_GPPU); |
jimherd | 0:a6a5d942b58f | 253 | } |
jimherd | 0:a6a5d942b58f | 254 |