OneWire Library lets you access 1-wire devices made by Maxim/Dallas, such as temperature sensors
Dependents: OneWireTest mbed_blinky Affich_Lum_Moist Projetv0 ... more
#include "mbed.h" #include "OneWire.h" OneWire owBus(p21); int main() { char _id[16]; DeviceAddresses* devAddresses = owBus.getFoundDevAddresses(); uint8_t foundNum = owBus.getFoundDevNum(); printf("OneWire: found %d devices\r\n", foundNum); while(1) { OneWireDeviceTemperature::startConversationForAll(&owBus, OWTEMP_11_BIT); for (uint8_t i = 0; i < foundNum; i++) { OneWireDevice* owDevice = OneWireDeviceFactory::init(&owBus, (*devAddresses)[i]); if (owDevice->getFamily() != ONEWIRE_DS18B20_FAMILY) // currently only DS18B20 supports continue; owDevice->generateId(_id); printf("OneWire: device #%s = %.4f*C\r\n", _id, (float) owDevice->sendGetCommand(GET_TEMPERATURE)); delete owDevice; } wait(5); } }
OneWire.cpp@2:07da4deb7135, 2012-12-18 (annotated)
- Committer:
- ivank
- Date:
- Tue Dec 18 11:40:28 2012 +0000
- Revision:
- 2:07da4deb7135
- Parent:
- 1:74dcd0c7d5d4
- splited library to seprated files; - fixed bug with GET_TEMPERATURE & IRQ(interrupts) under RTOS
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
ivank | 1:74dcd0c7d5d4 | 1 | /* Copyright (c) 2012, Ivan Kravets <me@ikravets.com>, www.ikravets.com. MIT License |
ivank | 1:74dcd0c7d5d4 | 2 | * |
ivank | 1:74dcd0c7d5d4 | 3 | * Permission is hereby granted, free of charge, to any person obtaining a copy of this software |
ivank | 1:74dcd0c7d5d4 | 4 | * and associated documentation files (the "Software"), to deal in the Software without restriction, |
ivank | 1:74dcd0c7d5d4 | 5 | * including without limitation the rights to use, copy, modify, merge, publish, distribute, |
ivank | 1:74dcd0c7d5d4 | 6 | * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is |
ivank | 1:74dcd0c7d5d4 | 7 | * furnished to do so, subject to the following conditions: |
ivank | 1:74dcd0c7d5d4 | 8 | * |
ivank | 1:74dcd0c7d5d4 | 9 | * The above copyright notice and this permission notice shall be included in all copies or |
ivank | 1:74dcd0c7d5d4 | 10 | * substantial portions of the Software. |
ivank | 1:74dcd0c7d5d4 | 11 | * |
ivank | 1:74dcd0c7d5d4 | 12 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING |
ivank | 1:74dcd0c7d5d4 | 13 | * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
ivank | 1:74dcd0c7d5d4 | 14 | * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, |
ivank | 1:74dcd0c7d5d4 | 15 | * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
ivank | 1:74dcd0c7d5d4 | 16 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
ivank | 1:74dcd0c7d5d4 | 17 | */ |
ivank | 1:74dcd0c7d5d4 | 18 | |
ivank | 1:74dcd0c7d5d4 | 19 | #include "OneWire.h" |
ivank | 1:74dcd0c7d5d4 | 20 | |
ivank | 1:74dcd0c7d5d4 | 21 | uint8_t const OneWire::dscrc_table[] = { |
ivank | 1:74dcd0c7d5d4 | 22 | 0, 94,188,226, 97, 63,221,131,194,156,126, 32,163,253, 31, 65, |
ivank | 1:74dcd0c7d5d4 | 23 | 157,195, 33,127,252,162, 64, 30, 95, 1,227,189, 62, 96,130,220, |
ivank | 1:74dcd0c7d5d4 | 24 | 35,125,159,193, 66, 28,254,160,225,191, 93, 3,128,222, 60, 98, |
ivank | 1:74dcd0c7d5d4 | 25 | 190,224, 2, 92,223,129, 99, 61,124, 34,192,158, 29, 67,161,255, |
ivank | 1:74dcd0c7d5d4 | 26 | 70, 24,250,164, 39,121,155,197,132,218, 56,102,229,187, 89, 7, |
ivank | 1:74dcd0c7d5d4 | 27 | 219,133,103, 57,186,228, 6, 88, 25, 71,165,251,120, 38,196,154, |
ivank | 1:74dcd0c7d5d4 | 28 | 101, 59,217,135, 4, 90,184,230,167,249, 27, 69,198,152,122, 36, |
ivank | 1:74dcd0c7d5d4 | 29 | 248,166, 68, 26,153,199, 37,123, 58,100,134,216, 91, 5,231,185, |
ivank | 1:74dcd0c7d5d4 | 30 | 140,210, 48,110,237,179, 81, 15, 78, 16,242,172, 47,113,147,205, |
ivank | 1:74dcd0c7d5d4 | 31 | 17, 79,173,243,112, 46,204,146,211,141,111, 49,178,236, 14, 80, |
ivank | 1:74dcd0c7d5d4 | 32 | 175,241, 19, 77,206,144,114, 44,109, 51,209,143, 12, 82,176,238, |
ivank | 1:74dcd0c7d5d4 | 33 | 50,108,142,208, 83, 13,239,177,240,174, 76, 18,145,207, 45,115, |
ivank | 1:74dcd0c7d5d4 | 34 | 202,148,118, 40,171,245, 23, 73, 8, 86,180,234,105, 55,213,139, |
ivank | 1:74dcd0c7d5d4 | 35 | 87, 9,235,181, 54,104,138,212,149,203, 41,119,244,170, 72, 22, |
ivank | 1:74dcd0c7d5d4 | 36 | 233,183, 85, 11,136,214, 52,106, 43,117,151,201, 74, 20,246,168, |
ivank | 1:74dcd0c7d5d4 | 37 | 116, 42,200,150, 21, 75,169,247,182,232, 10, 84,215,137,107, 53 |
ivank | 1:74dcd0c7d5d4 | 38 | }; |
ivank | 1:74dcd0c7d5d4 | 39 | |
ivank | 1:74dcd0c7d5d4 | 40 | OneWire::OneWire(PinName pin) : DIO(pin) |
ivank | 1:74dcd0c7d5d4 | 41 | { |
ivank | 1:74dcd0c7d5d4 | 42 | DIO.output(); |
ivank | 1:74dcd0c7d5d4 | 43 | DIO = 0; |
ivank | 1:74dcd0c7d5d4 | 44 | DIO.input(); |
ivank | 1:74dcd0c7d5d4 | 45 | |
ivank | 1:74dcd0c7d5d4 | 46 | reset(); |
ivank | 1:74dcd0c7d5d4 | 47 | findDevAddresses(); |
ivank | 1:74dcd0c7d5d4 | 48 | } |
ivank | 1:74dcd0c7d5d4 | 49 | |
ivank | 1:74dcd0c7d5d4 | 50 | |
ivank | 1:74dcd0c7d5d4 | 51 | uint8_t OneWire::reset(void) |
ivank | 1:74dcd0c7d5d4 | 52 | { |
ivank | 1:74dcd0c7d5d4 | 53 | uint8_t presence; |
ivank | 1:74dcd0c7d5d4 | 54 | DIO.output(); |
ivank | 1:74dcd0c7d5d4 | 55 | DIO = 0; |
ivank | 1:74dcd0c7d5d4 | 56 | wait_us(480); |
ivank | 1:74dcd0c7d5d4 | 57 | DIO.input(); |
ivank | 1:74dcd0c7d5d4 | 58 | wait_us(70); |
ivank | 1:74dcd0c7d5d4 | 59 | presence = DIO; |
ivank | 1:74dcd0c7d5d4 | 60 | wait_us(410); |
ivank | 1:74dcd0c7d5d4 | 61 | return(presence); |
ivank | 1:74dcd0c7d5d4 | 62 | } |
ivank | 1:74dcd0c7d5d4 | 63 | |
ivank | 1:74dcd0c7d5d4 | 64 | uint8_t OneWire::readBit(void) |
ivank | 1:74dcd0c7d5d4 | 65 | { |
ivank | 1:74dcd0c7d5d4 | 66 | uint8_t retval; |
ivank | 1:74dcd0c7d5d4 | 67 | wait_us(1); |
ivank | 1:74dcd0c7d5d4 | 68 | DIO.output(); |
ivank | 1:74dcd0c7d5d4 | 69 | DIO = 0; |
ivank | 1:74dcd0c7d5d4 | 70 | wait_us(2); |
ivank | 1:74dcd0c7d5d4 | 71 | DIO.input(); |
ivank | 1:74dcd0c7d5d4 | 72 | wait_us(10); |
ivank | 1:74dcd0c7d5d4 | 73 | retval=DIO; |
ivank | 1:74dcd0c7d5d4 | 74 | wait_us(48); |
ivank | 1:74dcd0c7d5d4 | 75 | return(retval); |
ivank | 1:74dcd0c7d5d4 | 76 | } |
ivank | 1:74dcd0c7d5d4 | 77 | |
ivank | 1:74dcd0c7d5d4 | 78 | uint8_t OneWire::readByte(void) |
ivank | 1:74dcd0c7d5d4 | 79 | { |
ivank | 1:74dcd0c7d5d4 | 80 | uint8_t i, value=0; |
ivank | 1:74dcd0c7d5d4 | 81 | for (i=0; i<8; i++) { |
ivank | 2:07da4deb7135 | 82 | if (readBit()) |
ivank | 2:07da4deb7135 | 83 | value |= 0x01<<i; |
ivank | 1:74dcd0c7d5d4 | 84 | } |
ivank | 2:07da4deb7135 | 85 | return value; |
ivank | 1:74dcd0c7d5d4 | 86 | } |
ivank | 1:74dcd0c7d5d4 | 87 | |
ivank | 1:74dcd0c7d5d4 | 88 | void OneWire::writeBit(uint8_t bitval) |
ivank | 1:74dcd0c7d5d4 | 89 | { |
ivank | 1:74dcd0c7d5d4 | 90 | wait_us(1); |
ivank | 1:74dcd0c7d5d4 | 91 | DIO.output(); |
ivank | 1:74dcd0c7d5d4 | 92 | DIO = 0; |
ivank | 1:74dcd0c7d5d4 | 93 | wait_us(10); |
ivank | 2:07da4deb7135 | 94 | if (bitval) |
ivank | 2:07da4deb7135 | 95 | DIO = 1; |
ivank | 1:74dcd0c7d5d4 | 96 | wait_us(50); |
ivank | 1:74dcd0c7d5d4 | 97 | DIO.input(); |
ivank | 1:74dcd0c7d5d4 | 98 | } |
ivank | 1:74dcd0c7d5d4 | 99 | |
ivank | 1:74dcd0c7d5d4 | 100 | void OneWire::writeByte(uint8_t val) |
ivank | 1:74dcd0c7d5d4 | 101 | { |
ivank | 2:07da4deb7135 | 102 | uint8_t i, temp; |
ivank | 1:74dcd0c7d5d4 | 103 | for (i=0; i<8; i++) { |
ivank | 1:74dcd0c7d5d4 | 104 | temp = val>>i; |
ivank | 1:74dcd0c7d5d4 | 105 | temp &= 0x01; |
ivank | 1:74dcd0c7d5d4 | 106 | writeBit(temp); |
ivank | 1:74dcd0c7d5d4 | 107 | } |
ivank | 1:74dcd0c7d5d4 | 108 | } |
ivank | 1:74dcd0c7d5d4 | 109 | |
ivank | 1:74dcd0c7d5d4 | 110 | uint8_t OneWire::calcCRC( uint8_t x) |
ivank | 1:74dcd0c7d5d4 | 111 | { |
ivank | 1:74dcd0c7d5d4 | 112 | return dscrc_table[dowcrc^x]; |
ivank | 1:74dcd0c7d5d4 | 113 | } |
ivank | 1:74dcd0c7d5d4 | 114 | |
ivank | 1:74dcd0c7d5d4 | 115 | void OneWire::skip() |
ivank | 1:74dcd0c7d5d4 | 116 | { |
ivank | 1:74dcd0c7d5d4 | 117 | writeByte(0xcc); |
ivank | 1:74dcd0c7d5d4 | 118 | } |
ivank | 1:74dcd0c7d5d4 | 119 | |
ivank | 1:74dcd0c7d5d4 | 120 | void OneWire::select(uint8_t* devAddr) |
ivank | 1:74dcd0c7d5d4 | 121 | { |
ivank | 1:74dcd0c7d5d4 | 122 | writeByte(0x55); |
ivank | 1:74dcd0c7d5d4 | 123 | for (uint8_t i=0; i<8; i++) { |
ivank | 1:74dcd0c7d5d4 | 124 | writeByte(devAddr[i]); |
ivank | 1:74dcd0c7d5d4 | 125 | } |
ivank | 1:74dcd0c7d5d4 | 126 | } |
ivank | 1:74dcd0c7d5d4 | 127 | |
ivank | 1:74dcd0c7d5d4 | 128 | void OneWire::sendGlobalCommand(uint8_t cmd) |
ivank | 1:74dcd0c7d5d4 | 129 | { |
ivank | 1:74dcd0c7d5d4 | 130 | reset(); |
ivank | 1:74dcd0c7d5d4 | 131 | skip(); |
ivank | 1:74dcd0c7d5d4 | 132 | writeByte(cmd); |
ivank | 1:74dcd0c7d5d4 | 133 | } |
ivank | 1:74dcd0c7d5d4 | 134 | |
ivank | 1:74dcd0c7d5d4 | 135 | void OneWire::resetSearch(void) |
ivank | 1:74dcd0c7d5d4 | 136 | { |
ivank | 1:74dcd0c7d5d4 | 137 | lastDiscrep = 0; |
ivank | 1:74dcd0c7d5d4 | 138 | doneFlag = FALSE; |
ivank | 1:74dcd0c7d5d4 | 139 | } |
ivank | 1:74dcd0c7d5d4 | 140 | |
ivank | 1:74dcd0c7d5d4 | 141 | uint8_t OneWire::search(uint8_t* devAddr) |
ivank | 1:74dcd0c7d5d4 | 142 | { |
ivank | 1:74dcd0c7d5d4 | 143 | uint8_t m = 1; // ROM Bit index |
ivank | 1:74dcd0c7d5d4 | 144 | uint8_t n = 0; // ROM Byte index |
ivank | 1:74dcd0c7d5d4 | 145 | uint8_t k = 1; // bit mask |
ivank | 1:74dcd0c7d5d4 | 146 | uint8_t x = 0; |
ivank | 1:74dcd0c7d5d4 | 147 | uint8_t discrepMarker = 0; // discrepancy marker |
ivank | 1:74dcd0c7d5d4 | 148 | uint8_t g; // Output bit |
ivank | 1:74dcd0c7d5d4 | 149 | uint8_t nxt; // return value |
ivank | 1:74dcd0c7d5d4 | 150 | uint8_t flag; |
ivank | 1:74dcd0c7d5d4 | 151 | nxt = FALSE; // set the next flag to false |
ivank | 1:74dcd0c7d5d4 | 152 | dowcrc = 0; // reset the dowcrc |
ivank | 1:74dcd0c7d5d4 | 153 | DeviceAddress ROM; |
ivank | 1:74dcd0c7d5d4 | 154 | |
ivank | 1:74dcd0c7d5d4 | 155 | flag = reset(); // reset the 1-Wire |
ivank | 1:74dcd0c7d5d4 | 156 | if (flag||doneFlag) { // no parts -> return false |
ivank | 1:74dcd0c7d5d4 | 157 | lastDiscrep = 0; // reset the search |
ivank | 1:74dcd0c7d5d4 | 158 | return FALSE; |
ivank | 1:74dcd0c7d5d4 | 159 | } |
ivank | 1:74dcd0c7d5d4 | 160 | |
ivank | 1:74dcd0c7d5d4 | 161 | writeByte(0xF0); // send SearchROM command |
ivank | 1:74dcd0c7d5d4 | 162 | do { // for all eight bytes |
ivank | 1:74dcd0c7d5d4 | 163 | x = 0; |
ivank | 2:07da4deb7135 | 164 | if (readBit()) x = 2; |
ivank | 1:74dcd0c7d5d4 | 165 | wait_us(120); |
ivank | 2:07da4deb7135 | 166 | if (readBit()) x |= 1; // and its complement |
ivank | 1:74dcd0c7d5d4 | 167 | if (x ==3) // there are no devices on the 1-Wire |
ivank | 1:74dcd0c7d5d4 | 168 | break; |
ivank | 1:74dcd0c7d5d4 | 169 | else { |
ivank | 1:74dcd0c7d5d4 | 170 | if (x>0) // all devices coupled have 0 or 1 |
ivank | 1:74dcd0c7d5d4 | 171 | g = x>>1; // bit write value for search |
ivank | 1:74dcd0c7d5d4 | 172 | else { |
ivank | 1:74dcd0c7d5d4 | 173 | // if this discrepancy is before the last discrepancy on a previous Next then pick the same as last time |
ivank | 1:74dcd0c7d5d4 | 174 | if (m<lastDiscrep) |
ivank | 1:74dcd0c7d5d4 | 175 | g = ((ROM[n]&k)>0); |
ivank | 1:74dcd0c7d5d4 | 176 | else // if equal to last pick 1 |
ivank | 1:74dcd0c7d5d4 | 177 | g = (m==lastDiscrep); // if not then pick 0 |
ivank | 1:74dcd0c7d5d4 | 178 | // if 0 was picked then record position with mask k |
ivank | 1:74dcd0c7d5d4 | 179 | if (g==0) discrepMarker = m; |
ivank | 1:74dcd0c7d5d4 | 180 | } |
ivank | 1:74dcd0c7d5d4 | 181 | if (g==1) // isolate bit in ROM[n] with mask k |
ivank | 1:74dcd0c7d5d4 | 182 | ROM[n] |= k; |
ivank | 1:74dcd0c7d5d4 | 183 | else |
ivank | 1:74dcd0c7d5d4 | 184 | ROM[n] &= ~k; |
ivank | 1:74dcd0c7d5d4 | 185 | writeBit(g); // ROM search write |
ivank | 1:74dcd0c7d5d4 | 186 | m++; // increment bit counter m |
ivank | 1:74dcd0c7d5d4 | 187 | k = k<<1; // and shift the bit mask k |
ivank | 1:74dcd0c7d5d4 | 188 | if (k==0) { // if the mask is 0 then go to new ROM // byte n and reset mask |
ivank | 1:74dcd0c7d5d4 | 189 | dowcrc = calcCRC(ROM[n]); // accumulate the CRC |
ivank | 1:74dcd0c7d5d4 | 190 | n++; |
ivank | 1:74dcd0c7d5d4 | 191 | k++; |
ivank | 1:74dcd0c7d5d4 | 192 | } |
ivank | 1:74dcd0c7d5d4 | 193 | } |
ivank | 1:74dcd0c7d5d4 | 194 | } while (n<8); //loop until through all ROM bytes 0-7 |
ivank | 1:74dcd0c7d5d4 | 195 | if (m<65||dowcrc) // if search was unsuccessful then |
ivank | 1:74dcd0c7d5d4 | 196 | lastDiscrep=0; // reset the last discrepancy to 0 |
ivank | 1:74dcd0c7d5d4 | 197 | else { // search was successful, so set lastDiscrep, lastOne, nxt |
ivank | 1:74dcd0c7d5d4 | 198 | lastDiscrep = discrepMarker; |
ivank | 1:74dcd0c7d5d4 | 199 | doneFlag = (lastDiscrep==0); |
ivank | 1:74dcd0c7d5d4 | 200 | nxt = TRUE; // indicates search is not complete yet, more parts remain |
ivank | 1:74dcd0c7d5d4 | 201 | } |
ivank | 1:74dcd0c7d5d4 | 202 | |
ivank | 1:74dcd0c7d5d4 | 203 | for (uint8_t i = 0; i < 8; i++) |
ivank | 1:74dcd0c7d5d4 | 204 | devAddr[i] = ROM[i]; |
ivank | 1:74dcd0c7d5d4 | 205 | |
ivank | 1:74dcd0c7d5d4 | 206 | return nxt; |
ivank | 1:74dcd0c7d5d4 | 207 | } |
ivank | 1:74dcd0c7d5d4 | 208 | |
ivank | 1:74dcd0c7d5d4 | 209 | void OneWire::findDevAddresses(void) |
ivank | 1:74dcd0c7d5d4 | 210 | { |
ivank | 1:74dcd0c7d5d4 | 211 | foundDevNum = 0; |
ivank | 1:74dcd0c7d5d4 | 212 | resetSearch(); |
ivank | 1:74dcd0c7d5d4 | 213 | |
ivank | 1:74dcd0c7d5d4 | 214 | DeviceAddress devAddr; |
ivank | 1:74dcd0c7d5d4 | 215 | while (search(devAddr)) { |
ivank | 1:74dcd0c7d5d4 | 216 | foundDevNum++; |
ivank | 1:74dcd0c7d5d4 | 217 | } |
ivank | 1:74dcd0c7d5d4 | 218 | delete devAddr; |
ivank | 1:74dcd0c7d5d4 | 219 | |
ivank | 1:74dcd0c7d5d4 | 220 | wait_us(250); |
ivank | 1:74dcd0c7d5d4 | 221 | resetSearch(); |
ivank | 1:74dcd0c7d5d4 | 222 | |
ivank | 1:74dcd0c7d5d4 | 223 | foundDevAdresses = (DeviceAddresses*) malloc(foundDevNum * sizeof(int)); |
ivank | 1:74dcd0c7d5d4 | 224 | for (uint8_t i = 0; i < foundDevNum; i++) { |
ivank | 1:74dcd0c7d5d4 | 225 | foundDevAdresses[i] = (DeviceAddress*) malloc(sizeof(DeviceAddress)); |
ivank | 1:74dcd0c7d5d4 | 226 | search((*foundDevAdresses)[i]); |
ivank | 1:74dcd0c7d5d4 | 227 | } |
ivank | 1:74dcd0c7d5d4 | 228 | |
ivank | 1:74dcd0c7d5d4 | 229 | printf("OneWire Bus: Found %d devices\r\n", getFoundDevNum() ); |
ivank | 1:74dcd0c7d5d4 | 230 | } |
ivank | 1:74dcd0c7d5d4 | 231 | |
ivank | 1:74dcd0c7d5d4 | 232 | DeviceAddresses* OneWire::getFoundDevAddresses() |
ivank | 1:74dcd0c7d5d4 | 233 | { |
ivank | 1:74dcd0c7d5d4 | 234 | return foundDevAdresses; |
ivank | 1:74dcd0c7d5d4 | 235 | } |
ivank | 1:74dcd0c7d5d4 | 236 | |
ivank | 1:74dcd0c7d5d4 | 237 | uint8_t OneWire::getFoundDevNum() |
ivank | 1:74dcd0c7d5d4 | 238 | { |
ivank | 1:74dcd0c7d5d4 | 239 | return foundDevNum; |
ivank | 2:07da4deb7135 | 240 | } |