Erik - / DS1820

Library for reading temperature from DS1820, DS18B20 and DS1822

Dependencies:   LinkedList

Dependents:   heatmap BLE_Temperature BLE_Temperature_Exercise F334andDS18B20 ... more

Fork of DS1820 by David Pairman

HelloWorld: http://mbed.org/users/Sissors/code/DS1820_HelloWorld/

Library should currently work on all mbed targets, let me know if there is an issue. First however make sure you have latest version of mbed library and this library.

DS1820.h@0:61d83318f2d6, 2010-12-19 (annotated)

Committer:
Michael_
Date:
Sun Dec 19 05:40:28 2010 +0000
Revision:
0:61d83318f2d6
Child:
1:6a427f54e82c
Dec 18, 2010 First pubication

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Michael_ 0:61d83318f2d6 1 /* mbed DS1820 Library, for the Dallas (Maxim) 1-Wire Digital Thermometer
Michael_ 0:61d83318f2d6 2 * Copyright (c) 2010, Michael Hagberg Michael@RedBoxCode.com
Michael_ 0:61d83318f2d6 3 *
Michael_ 0:61d83318f2d6 4 * Permission is hereby granted, free of charge, to any person obtaining a copy
Michael_ 0:61d83318f2d6 5 * of this software and associated documentation files (the "Software"), to deal
Michael_ 0:61d83318f2d6 6 * in the Software without restriction, including without limitation the rights
Michael_ 0:61d83318f2d6 7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
Michael_ 0:61d83318f2d6 8 * copies of the Software, and to permit persons to whom the Software is
Michael_ 0:61d83318f2d6 9 * furnished to do so, subject to the following conditions:
Michael_ 0:61d83318f2d6 10 *
Michael_ 0:61d83318f2d6 11 * The above copyright notice and this permission notice shall be included in
Michael_ 0:61d83318f2d6 12 * all copies or substantial portions of the Software.
Michael_ 0:61d83318f2d6 13 *
Michael_ 0:61d83318f2d6 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
Michael_ 0:61d83318f2d6 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
Michael_ 0:61d83318f2d6 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
Michael_ 0:61d83318f2d6 17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
Michael_ 0:61d83318f2d6 18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
Michael_ 0:61d83318f2d6 19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
Michael_ 0:61d83318f2d6 20 * THE SOFTWARE.
Michael_ 0:61d83318f2d6 21 */
Michael_ 0:61d83318f2d6 22
Michael_ 0:61d83318f2d6 23 #ifndef MBED_DS1820_H
Michael_ 0:61d83318f2d6 24 #define MBED_DS1820_H
Michael_ 0:61d83318f2d6 25
Michael_ 0:61d83318f2d6 26 #include "mbed.h"
Michael_ 0:61d83318f2d6 27
Michael_ 0:61d83318f2d6 28 // ****** THIS GLOBAL VARIABLES MUST BE DEFINED IN main.cpp
Michael_ 0:61d83318f2d6 29
Michael_ 0:61d83318f2d6 30 // Global variables shared between all DS1820 objects
Michael_ 0:61d83318f2d6 31 //bool DS1820_done_flag;
Michael_ 0:61d83318f2d6 32 //int DS1820_last_descrepancy;
Michael_ 0:61d83318f2d6 33 //char DS1820_search_ROM[8];
Michael_ 0:61d83318f2d6 34
Michael_ 0:61d83318f2d6 35 /** DS1820 Dallas 1-Wire Temperature Probe
Michael_ 0:61d83318f2d6 36 *
Michael_ 0:61d83318f2d6 37 * Example:
Michael_ 0:61d83318f2d6 38 * @code
Michael_ 0:61d83318f2d6 39 * #include "mbed.h"
Michael_ 0:61d83318f2d6 40 *
Michael_ 0:61d83318f2d6 41 * #include "TextLCD.h"
Michael_ 0:61d83318f2d6 42 * #include "DS1820.h"
Michael_ 0:61d83318f2d6 43 *
Michael_ 0:61d83318f2d6 44 * TextLCD lcd(p25, p26, p21, p22, p23, p24, TextLCD::LCD16x2); // rs, e, d0-d3, layout
Michael_ 0:61d83318f2d6 45 *
Michael_ 0:61d83318f2d6 46 * const int MAX_PROBES = 16;
Michael_ 0:61d83318f2d6 47 * DS1820* probe[MAX_PROBES];
Michael_ 0:61d83318f2d6 48 *
Michael_ 0:61d83318f2d6 49 * int main() {
Michael_ 0:61d83318f2d6 50 * int i;
Michael_ 0:61d83318f2d6 51 * int devices_found=0;
Michael_ 0:61d83318f2d6 52 * // Initialize the probe array to DS1820 objects
Michael_ 0:61d83318f2d6 53 * for (i = 0; i < MAX_PROBES; i++)
Michael_ 0:61d83318f2d6 54 * probe[i] = new DS1820(p27);
Michael_ 0:61d83318f2d6 55 * // Initialize global state variables
Michael_ 0:61d83318f2d6 56 * probe[0]->search_ROM_setup();
Michael_ 0:61d83318f2d6 57 * // Loop to find all devices on the data line
Michael_ 0:61d83318f2d6 58 * while (probe[devices_found]->search_ROM() and devices_found<MAX_PROBES-1)
Michael_ 0:61d83318f2d6 59 * devices_found++;
Michael_ 0:61d83318f2d6 60 * // If maximum number of probes are found,
Michael_ 0:61d83318f2d6 61 * // bump the counter to include the last array entry
Michael_ 0:61d83318f2d6 62 * if (probe[devices_found]->ROM[0] != 0xFF)
Michael_ 0:61d83318f2d6 63 * devices_found++;
Michael_ 0:61d83318f2d6 64 *
Michael_ 0:61d83318f2d6 65 * lcd.cls();
Michael_ 0:61d83318f2d6 66 * if (devices_found==0)
Michael_ 0:61d83318f2d6 67 * lcd.printf("No devices found");
Michael_ 0:61d83318f2d6 68 * else {
Michael_ 0:61d83318f2d6 69 * while (true) {
Michael_ 0:61d83318f2d6 70 * probe[0]->convert_temperature(DS1820::all_devices);
Michael_ 0:61d83318f2d6 71 * lcd.cls();
Michael_ 0:61d83318f2d6 72 * for (i=0; i<devices_found; i++) {
Michael_ 0:61d83318f2d6 73 * lcd.printf("%3.1f ",probe[i]->temperature('f'));
Michael_ 0:61d83318f2d6 74 * }
Michael_ 0:61d83318f2d6 75 * }
Michael_ 0:61d83318f2d6 76 * }
Michael_ 0:61d83318f2d6 77 * }
Michael_ 0:61d83318f2d6 78 * @endcode
Michael_ 0:61d83318f2d6 79 */
Michael_ 0:61d83318f2d6 80
Michael_ 0:61d83318f2d6 81 class DS1820 {
Michael_ 0:61d83318f2d6 82 public:
Michael_ 0:61d83318f2d6 83 enum devices{
Michael_ 0:61d83318f2d6 84 this_device, // command applies to only this device
Michael_ 0:61d83318f2d6 85 all_devices }; // command applies to all devices
Michael_ 0:61d83318f2d6 86
Michael_ 0:61d83318f2d6 87 /** Create a probe object connected to the specified pins
Michael_ 0:61d83318f2d6 88 *
Michael_ 0:61d83318f2d6 89 * @param data_pin DigitalInOut pin for the data bus
Michael_ 0:61d83318f2d6 90 * @param power_pin DigitalOut pin to control the power MOSFET
Michael_ 0:61d83318f2d6 91 */
Michael_ 0:61d83318f2d6 92 DS1820(PinName data_pin, PinName power_pin); // Constructor with parasite power pin
Michael_ 0:61d83318f2d6 93
Michael_ 0:61d83318f2d6 94 /** Create a probe object connected to the specified pin
Michael_ 0:61d83318f2d6 95 * this is used when all probes are externally powered
Michael_ 0:61d83318f2d6 96 *
Michael_ 0:61d83318f2d6 97 * @param data_pin DigitalInOut pin for the data bus
Michael_ 0:61d83318f2d6 98 */
Michael_ 0:61d83318f2d6 99 DS1820(PinName data_pin);
Michael_ 0:61d83318f2d6 100
Michael_ 0:61d83318f2d6 101 /** ROM is a copy of the internal DS1820's ROM
Michael_ 0:61d83318f2d6 102 * It's created during the search_ROM() or search_alarm() commands
Michael_ 0:61d83318f2d6 103 *
Michael_ 0:61d83318f2d6 104 * ROM[0] is the Dallas Family Code
Michael_ 0:61d83318f2d6 105 * ROM[1] thru ROM[6] is the 48-bit unique serial number
Michael_ 0:61d83318f2d6 106 * ROM[7] is the device CRC
Michael_ 0:61d83318f2d6 107 */
Michael_ 0:61d83318f2d6 108 char ROM[8];
Michael_ 0:61d83318f2d6 109
Michael_ 0:61d83318f2d6 110 /** RAM is a copy of the internal DS1820's RAM
Michael_ 0:61d83318f2d6 111 * It's updated during the read_RAM() command
Michael_ 0:61d83318f2d6 112 * which is automaticaly called from any function
Michael_ 0:61d83318f2d6 113 * using the RAM values.
Michael_ 0:61d83318f2d6 114 */
Michael_ 0:61d83318f2d6 115 char RAM[9];
Michael_ 0:61d83318f2d6 116
Michael_ 0:61d83318f2d6 117 /* This function copies the DS1820's RAM into the object's
Michael_ 0:61d83318f2d6 118 * RAM[].
Michael_ 0:61d83318f2d6 119 */
Michael_ 0:61d83318f2d6 120 void read_RAM();
Michael_ 0:61d83318f2d6 121
Michael_ 0:61d83318f2d6 122 /** This routine initializes the global variables used in
Michael_ 0:61d83318f2d6 123 * the search_ROM() and search_alarm() funtions. It should
Michael_ 0:61d83318f2d6 124 * be called once before looping to find devices.
Michael_ 0:61d83318f2d6 125 */
Michael_ 0:61d83318f2d6 126 void search_ROM_setup();
Michael_ 0:61d83318f2d6 127
Michael_ 0:61d83318f2d6 128 /** This routine will search for an unidentified device
Michael_ 0:61d83318f2d6 129 * on the bus. It uses the variables in search_ROM_setup
Michael_ 0:61d83318f2d6 130 * to remember the pervious ROM address found.
Michael_ 0:61d83318f2d6 131 * It will return FALSE if there were no new devices
Michael_ 0:61d83318f2d6 132 * discovered on the bus.
Michael_ 0:61d83318f2d6 133 */
Michael_ 0:61d83318f2d6 134 bool search_ROM();
Michael_ 0:61d83318f2d6 135
Michael_ 0:61d83318f2d6 136 /** This routine will search for an unidentified device
Michael_ 0:61d83318f2d6 137 * which has the temperature alarm bit set. It uses the
Michael_ 0:61d83318f2d6 138 * variables in search_ROM_setup to remember the pervious
Michael_ 0:61d83318f2d6 139 * ROM address found. It will return FALSE if there were
Michael_ 0:61d83318f2d6 140 * no new devices with alarms discovered on the bus.
Michael_ 0:61d83318f2d6 141 */
Michael_ 0:61d83318f2d6 142 bool search_alarm();
Michael_ 0:61d83318f2d6 143
Michael_ 0:61d83318f2d6 144 /** This routine will read the ROM (Family code, serial number
Michael_ 0:61d83318f2d6 145 * and Checksum) from a dedicated device on the bus.
Michael_ 0:61d83318f2d6 146 *
Michael_ 0:61d83318f2d6 147 * NOTE: This command can only be used when there is only one
Michael_ 0:61d83318f2d6 148 * DS1820 on the bus. If this command is used when there
Michael_ 0:61d83318f2d6 149 * is more than one slave present on the bus, a data
Michael_ 0:61d83318f2d6 150 * collision will occur when all the DS1820s attempt to
Michael_ 0:61d83318f2d6 151 * respond at the same time.
Michael_ 0:61d83318f2d6 152 */
Michael_ 0:61d83318f2d6 153 void read_ROM();
Michael_ 0:61d83318f2d6 154
Michael_ 0:61d83318f2d6 155 /** This routine will initiate the temperature conversion within
Michael_ 0:61d83318f2d6 156 * a DS1820. There is a built in 750ms delay to allow the
Michael_ 0:61d83318f2d6 157 * conversion to complete.
Michael_ 0:61d83318f2d6 158 *
Michael_ 0:61d83318f2d6 159 * To update all probes on the bus, use a statement such as this:
Michael_ 0:61d83318f2d6 160 * probe[0]->convert_temperature(DS1820::all_devices);
Michael_ 0:61d83318f2d6 161 *
Michael_ 0:61d83318f2d6 162 * @param allows the fnction to apply to a specific device or
Michael_ 0:61d83318f2d6 163 * to all devices on the 1-Wire bus.
Michael_ 0:61d83318f2d6 164 */
Michael_ 0:61d83318f2d6 165 void convert_temperature(devices device=this_device);
Michael_ 0:61d83318f2d6 166
Michael_ 0:61d83318f2d6 167 /** This function will return the probe temperature. This function
Michael_ 0:61d83318f2d6 168 * uses the count remainding values to interpolate the temperature
Michael_ 0:61d83318f2d6 169 * to about 1/150th of a degree. Whereas the probe is not spec to
Michael_ 0:61d83318f2d6 170 * that precision. It does seem to give a smooth reading to the
Michael_ 0:61d83318f2d6 171 * tenth of a degree.
Michael_ 0:61d83318f2d6 172 *
Michael_ 0:61d83318f2d6 173 * @param scale, may be either 'c' or 'f'
Michael_ 0:61d83318f2d6 174 * @returns temperature for that scale
Michael_ 0:61d83318f2d6 175 */
Michael_ 0:61d83318f2d6 176 float temperature(char scale='c');
Michael_ 0:61d83318f2d6 177
Michael_ 0:61d83318f2d6 178 /** This function calculates the ROM checksum and compares it to the
Michael_ 0:61d83318f2d6 179 * CRC value stored in ROM[7].
Michael_ 0:61d83318f2d6 180 *
Michael_ 0:61d83318f2d6 181 * @returns true if the checksum matches, otherwise false.
Michael_ 0:61d83318f2d6 182 */
Michael_ 0:61d83318f2d6 183 bool ROM_checksum_error();
Michael_ 0:61d83318f2d6 184
Michael_ 0:61d83318f2d6 185 /** This function calculates the RAM checksum and compares it to the
Michael_ 0:61d83318f2d6 186 * CRC value stored in RAM[8].
Michael_ 0:61d83318f2d6 187 *
Michael_ 0:61d83318f2d6 188 * @returns true if the checksum matches, otherwise false.
Michael_ 0:61d83318f2d6 189 */
Michael_ 0:61d83318f2d6 190 bool RAM_checksum_error();
Michael_ 0:61d83318f2d6 191
Michael_ 0:61d83318f2d6 192 /** This funtion returns the values stored in the temperature
Michael_ 0:61d83318f2d6 193 * alarm registers.
Michael_ 0:61d83318f2d6 194 *
Michael_ 0:61d83318f2d6 195 * @returns a 16 bit integer of TH (upper byte) and TL (lower byte).
Michael_ 0:61d83318f2d6 196 */
Michael_ 0:61d83318f2d6 197 int read_scratchpad();
Michael_ 0:61d83318f2d6 198
Michael_ 0:61d83318f2d6 199 /** This function will store the passed data into the DS1820's RAM.
Michael_ 0:61d83318f2d6 200 * Note: It does NOT save the data to the EEPROM for retention
Michael_ 0:61d83318f2d6 201 * during cycling the power off and on.
Michael_ 0:61d83318f2d6 202 *
Michael_ 0:61d83318f2d6 203 * @param a 16 bit integer of TH (upper byte) and TL (lower byte).
Michael_ 0:61d83318f2d6 204 */
Michael_ 0:61d83318f2d6 205 void write_scratchpad(int data);
Michael_ 0:61d83318f2d6 206
Michael_ 0:61d83318f2d6 207 /** This function will transfer the TH and TL registers from the
Michael_ 0:61d83318f2d6 208 * DS1820's RAM into the EEPROM.
Michael_ 0:61d83318f2d6 209 * Note: There is a built in 10ms delay to allow for the
Michael_ 0:61d83318f2d6 210 * completion of the EEPROM write cycle.
Michael_ 0:61d83318f2d6 211 *
Michael_ 0:61d83318f2d6 212 * @param allows the fnction to apply to a specific device or
Michael_ 0:61d83318f2d6 213 * to all devices on the 1-Wire bus.
Michael_ 0:61d83318f2d6 214 */
Michael_ 0:61d83318f2d6 215 void store_scratchpad(devices device=this_device);
Michael_ 0:61d83318f2d6 216
Michael_ 0:61d83318f2d6 217 /** This function will copy the stored values from the EEPROM
Michael_ 0:61d83318f2d6 218 * into the DS1820's RAM locations for TH and TL.
Michael_ 0:61d83318f2d6 219 *
Michael_ 0:61d83318f2d6 220 * @param allows the fnction to apply to a specific device or
Michael_ 0:61d83318f2d6 221 * to all devices on the 1-Wire bus.
Michael_ 0:61d83318f2d6 222 */
Michael_ 0:61d83318f2d6 223 int recall_scratchpad(devices device=this_device);
Michael_ 0:61d83318f2d6 224
Michael_ 0:61d83318f2d6 225 /** This function will return the type of power supply for
Michael_ 0:61d83318f2d6 226 * a specific device. It can also be used to query all devices
Michael_ 0:61d83318f2d6 227 * looking for any device that is parasite powered.
Michael_ 0:61d83318f2d6 228 *
Michael_ 0:61d83318f2d6 229 * @returns true if the device (or all devices) are Vcc powered,
Michael_ 0:61d83318f2d6 230 * returns false if the device (or ANY device) is parasite powered.
Michael_ 0:61d83318f2d6 231 */
Michael_ 0:61d83318f2d6 232 bool read_power_supply(devices device=this_device);
Michael_ 0:61d83318f2d6 233
Michael_ 0:61d83318f2d6 234 private:
Michael_ 0:61d83318f2d6 235 bool _parasite_power;
Michael_ 0:61d83318f2d6 236 char CRC_byte (char CRC, char byte );
Michael_ 0:61d83318f2d6 237 bool onewire_reset();
Michael_ 0:61d83318f2d6 238 void match_ROM();
Michael_ 0:61d83318f2d6 239 void skip_ROM();
Michael_ 0:61d83318f2d6 240 bool search_ROM_routine(char command);
Michael_ 0:61d83318f2d6 241 void onewire_bit_out (bool bit_data);
Michael_ 0:61d83318f2d6 242 void onewire_byte_out(char data);
Michael_ 0:61d83318f2d6 243 bool onewire_bit_in();
Michael_ 0:61d83318f2d6 244 char onewire_byte_in();
Michael_ 0:61d83318f2d6 245
Michael_ 0:61d83318f2d6 246 protected:
Michael_ 0:61d83318f2d6 247 DigitalInOut _datapin;
Michael_ 0:61d83318f2d6 248 DigitalOut _parasitepin;
Michael_ 0:61d83318f2d6 249 };
Michael_ 0:61d83318f2d6 250
Michael_ 0:61d83318f2d6 251
Michael_ 0:61d83318f2d6 252 #endif