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@2:ee820a991b95, 2011-12-15 (annotated)

Committer:
Michael_
Date:
Thu Dec 15 19:07:36 2011 +0000
Revision:
2:ee820a991b95
Parent:
1:6a427f54e82c
Child:
3:8f2b7f4940b5
Updated documentation. (maybe)

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Michael_ 2:ee820a991b95 1 /* mbed DS1820 Library, for the Dallas (Maxim) 1-Wire Digital Thermometer
Michael_ 2:ee820a991b95 2 * Copyright (c) 2010, Michael Hagberg Michael@RedBoxCode.com
Michael_ 2:ee820a991b95 3 *
Michael_ 2:ee820a991b95 4 * Permission is hereby granted, free of charge, to any person obtaining a copy
Michael_ 2:ee820a991b95 5 * of this software and associated documentation files (the "Software"), to deal
Michael_ 2:ee820a991b95 6 * in the Software without restriction, including without limitation the rights
Michael_ 2:ee820a991b95 7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
Michael_ 2:ee820a991b95 8 * copies of the Software, and to permit persons to whom the Software is
Michael_ 2:ee820a991b95 9 * furnished to do so, subject to the following conditions:
Michael_ 2:ee820a991b95 10 *
Michael_ 2:ee820a991b95 11 * The above copyright notice and this permission notice shall be included in
Michael_ 2:ee820a991b95 12 * all copies or substantial portions of the Software.
Michael_ 2:ee820a991b95 13 *
Michael_ 2:ee820a991b95 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
Michael_ 2:ee820a991b95 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
Michael_ 2:ee820a991b95 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
Michael_ 2:ee820a991b95 17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
Michael_ 2:ee820a991b95 18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
Michael_ 2:ee820a991b95 19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
Michael_ 2:ee820a991b95 20 * THE SOFTWARE.
Michael_ 2:ee820a991b95 21 */
Michael_ 2:ee820a991b95 22
Michael_ 2:ee820a991b95 23 #ifndef MBED_DS1820_H
Michael_ 2:ee820a991b95 24 #define MBED_DS1820_H
Michael_ 2:ee820a991b95 25
Michael_ 2:ee820a991b95 26 #include "mbed.h"
Michael_ 2:ee820a991b95 27
Michael_ 2:ee820a991b95 28 // ****** THIS GLOBAL VARIABLES MUST BE DEFINED IN main.cpp
Michael_ 2:ee820a991b95 29
Michael_ 2:ee820a991b95 30 // Global variables shared between all DS1820 objects
Michael_ 2:ee820a991b95 31 //bool DS1820_done_flag;
Michael_ 2:ee820a991b95 32 //int DS1820_last_descrepancy;
Michael_ 2:ee820a991b95 33 //char DS1820_search_ROM[8];
Michael_ 2:ee820a991b95 34
Michael_ 2:ee820a991b95 35 /** DS1820 Dallas 1-Wire Temperature Probe
Michael_ 2:ee820a991b95 36 *
Michael_ 2:ee820a991b95 37 * Example:
Michael_ 2:ee820a991b95 38 * @code
Michael_ 2:ee820a991b95 39 * #include "mbed.h"
Michael_ 2:ee820a991b95 40 *
Michael_ 2:ee820a991b95 41 * #include "TextLCD.h"
Michael_ 2:ee820a991b95 42 * #include "DS1820.h"
Michael_ 2:ee820a991b95 43 *
Michael_ 2:ee820a991b95 44 * TextLCD lcd(p25, p26, p21, p22, p23, p24, TextLCD::LCD16x2); // rs, e, d0-d3, layout
Michael_ 2:ee820a991b95 45 *
Michael_ 2:ee820a991b95 46 * const int MAX_PROBES = 16;
Michael_ 2:ee820a991b95 47 * DS1820* probe[MAX_PROBES];
Michael_ 2:ee820a991b95 48 *
Michael_ 2:ee820a991b95 49 * int main() {
Michael_ 2:ee820a991b95 50 * int i;
Michael_ 2:ee820a991b95 51 * int devices_found=0;
Michael_ 2:ee820a991b95 52 * // Initialize the probe array to DS1820 objects
Michael_ 2:ee820a991b95 53 * for (i = 0; i < MAX_PROBES; i++)
Michael_ 2:ee820a991b95 54 * probe[i] = new DS1820(p27);
Michael_ 2:ee820a991b95 55 * // Initialize global state variables
Michael_ 2:ee820a991b95 56 * probe[0]->search_ROM_setup();
Michael_ 2:ee820a991b95 57 * // Loop to find all devices on the data line
Michael_ 2:ee820a991b95 58 * while (probe[devices_found]->search_ROM() and devices_found<MAX_PROBES-1)
Michael_ 2:ee820a991b95 59 * devices_found++;
Michael_ 2:ee820a991b95 60 * // If maximum number of probes are found,
Michael_ 2:ee820a991b95 61 * // bump the counter to include the last array entry
Michael_ 2:ee820a991b95 62 * if (probe[devices_found]->ROM[0] != 0xFF)
Michael_ 2:ee820a991b95 63 * devices_found++;
Michael_ 2:ee820a991b95 64 *
Michael_ 2:ee820a991b95 65 * lcd.cls();
Michael_ 2:ee820a991b95 66 * if (devices_found==0)
Michael_ 2:ee820a991b95 67 * lcd.printf("No devices found");
Michael_ 2:ee820a991b95 68 * else {
Michael_ 2:ee820a991b95 69 * while (true) {
Michael_ 2:ee820a991b95 70 * probe[0]->convert_temperature(DS1820::all_devices);
Michael_ 2:ee820a991b95 71 * lcd.cls();
Michael_ 2:ee820a991b95 72 * for (i=0; i<devices_found; i++) {
Michael_ 2:ee820a991b95 73 * lcd.printf("%3.1f ",probe[i]->temperature('f'));
Michael_ 2:ee820a991b95 74 * }
Michael_ 2:ee820a991b95 75 * }
Michael_ 2:ee820a991b95 76 * }
Michael_ 2:ee820a991b95 77 * }
Michael_ 2:ee820a991b95 78 * @endcode
Michael_ 2:ee820a991b95 79 */
Michael_ 2:ee820a991b95 80
Michael_ 2:ee820a991b95 81 class DS1820 {
Michael_ 2:ee820a991b95 82 public:
Michael_ 2:ee820a991b95 83 enum devices{
Michael_ 2:ee820a991b95 84 this_device, // command applies to only this device
Michael_ 2:ee820a991b95 85 all_devices }; // command applies to all devices
Michael_ 2:ee820a991b95 86
Michael_ 2:ee820a991b95 87 /** Create a probe object connected to the specified pins
Michael_ 2:ee820a991b95 88 *
Michael_ 2:ee820a991b95 89 * @param data_pin DigitalInOut pin for the data bus
Michael_ 2:ee820a991b95 90 * @param power_pin DigitalOut pin to control the power MOSFET
Michael_ 2:ee820a991b95 91 */
Michael_ 2:ee820a991b95 92 DS1820(PinName data_pin, PinName power_pin); // Constructor with parasite power pin
Michael_ 2:ee820a991b95 93
Michael_ 2:ee820a991b95 94 /** Create a probe object connected to the specified pin
Michael_ 2:ee820a991b95 95 * this is used when all probes are externally powered
Michael_ 2:ee820a991b95 96 *
Michael_ 2:ee820a991b95 97 * @param data_pin DigitalInOut pin for the data bus
Michael_ 2:ee820a991b95 98 */
Michael_ 2:ee820a991b95 99 DS1820(PinName data_pin);
Michael_ 2:ee820a991b95 100
Michael_ 2:ee820a991b95 101 /** ROM is a copy of the internal DS1820's ROM
Michael_ 2:ee820a991b95 102 * It is created during the search_ROM() or search_alarm() commands
Michael_ 2:ee820a991b95 103 *
Michael_ 2:ee820a991b95 104 * ROM[0] is the Dallas Family Code
Michael_ 2:ee820a991b95 105 * ROM[1] thru ROM[6] is the 48-bit unique serial number
Michael_ 2:ee820a991b95 106 * ROM[7] is the device CRC
Michael_ 2:ee820a991b95 107 */
Michael_ 2:ee820a991b95 108 char ROM[8];
Michael_ 2:ee820a991b95 109 #define FAMILY_CODE ROM[0]
Michael_ 2:ee820a991b95 110 #define FAMILY_CODE_DS1820 0x10
Michael_ 2:ee820a991b95 111 #define FAMILY_CODE_DS18S20 0x10
Michael_ 2:ee820a991b95 112 #define FAMILY_CODE_DS18B20 0x28
Michael_ 2:ee820a991b95 113
Michael_ 2:ee820a991b95 114 /** RAM is a copy of the internal DS1820's RAM
Michael_ 2:ee820a991b95 115 * It's updated during the read_RAM() command
Michael_ 2:ee820a991b95 116 * which is automaticaly called from any function
Michael_ 2:ee820a991b95 117 * using the RAM values.
Michael_ 2:ee820a991b95 118 */
Michael_ 2:ee820a991b95 119 char RAM[9];
Michael_ 2:ee820a991b95 120
Michael_ 2:ee820a991b95 121 /* This function copies the DS1820's RAM into the object's
Michael_ 2:ee820a991b95 122 * RAM[].
Michael_ 2:ee820a991b95 123 */
Michael_ 2:ee820a991b95 124 void read_RAM();
Michael_ 2:ee820a991b95 125
Michael_ 2:ee820a991b95 126 /** This routine initializes the global variables used in
Michael_ 2:ee820a991b95 127 * the search_ROM() and search_alarm() funtions. It should
Michael_ 2:ee820a991b95 128 * be called once before looping to find devices.
Michael_ 2:ee820a991b95 129 */
Michael_ 2:ee820a991b95 130 void search_ROM_setup();
Michael_ 2:ee820a991b95 131
Michael_ 2:ee820a991b95 132 /** This routine will search for an unidentified device
Michael_ 2:ee820a991b95 133 * on the bus. It uses the variables in search_ROM_setup
Michael_ 2:ee820a991b95 134 * to remember the pervious ROM address found.
Michael_ 2:ee820a991b95 135 * It will return FALSE if there were no new devices
Michael_ 2:ee820a991b95 136 * discovered on the bus.
Michael_ 2:ee820a991b95 137 */
Michael_ 2:ee820a991b95 138 bool search_ROM();
Michael_ 2:ee820a991b95 139
Michael_ 2:ee820a991b95 140 /** This routine will search for an unidentified device
Michael_ 2:ee820a991b95 141 * which has the temperature alarm bit set. It uses the
Michael_ 2:ee820a991b95 142 * variables in search_ROM_setup to remember the pervious
Michael_ 2:ee820a991b95 143 * ROM address found. It will return FALSE if there were
Michael_ 2:ee820a991b95 144 * no new devices with alarms discovered on the bus.
Michael_ 2:ee820a991b95 145 */
Michael_ 2:ee820a991b95 146 bool search_alarm();
Michael_ 2:ee820a991b95 147
Michael_ 2:ee820a991b95 148 /** This routine will read the ROM (Family code, serial number
Michael_ 2:ee820a991b95 149 * and Checksum) from a dedicated device on the bus.
Michael_ 2:ee820a991b95 150 *
Michael_ 2:ee820a991b95 151 * NOTE: This command can only be used when there is only one
Michael_ 2:ee820a991b95 152 * DS1820 on the bus. If this command is used when there
Michael_ 2:ee820a991b95 153 * is more than one slave present on the bus, a data
Michael_ 2:ee820a991b95 154 * collision will occur when all the DS1820s attempt to
Michael_ 2:ee820a991b95 155 * respond at the same time.
Michael_ 2:ee820a991b95 156 */
Michael_ 2:ee820a991b95 157 void read_ROM();
Michael_ 2:ee820a991b95 158
Michael_ 2:ee820a991b95 159 /** This routine will initiate the temperature conversion within
Michael_ 2:ee820a991b95 160 * a DS1820. There is a built in 750ms delay to allow the
Michael_ 2:ee820a991b95 161 * conversion to complete.
Michael_ 2:ee820a991b95 162 *
Michael_ 2:ee820a991b95 163 * To update all probes on the bus, use a statement such as this:
Michael_ 2:ee820a991b95 164 * probe[0]->convert_temperature(DS1820::all_devices);
Michael_ 2:ee820a991b95 165 *
Michael_ 2:ee820a991b95 166 * @param allows the fnction to apply to a specific device or
Michael_ 2:ee820a991b95 167 * to all devices on the 1-Wire bus.
Michael_ 2:ee820a991b95 168 */
Michael_ 2:ee820a991b95 169 void convert_temperature(devices device=this_device);
Michael_ 2:ee820a991b95 170
Michael_ 2:ee820a991b95 171 /** This function will return the probe temperature. This function
Michael_ 2:ee820a991b95 172 * uses the count remainding values to interpolate the temperature
Michael_ 2:ee820a991b95 173 * to about 1/150th of a degree. Whereas the probe is not spec to
Michael_ 2:ee820a991b95 174 * that precision. It does seem to give a smooth reading to the
Michael_ 2:ee820a991b95 175 * tenth of a degree.
Michael_ 2:ee820a991b95 176 *
Michael_ 2:ee820a991b95 177 * @param scale, may be either 'c' or 'f'
Michael_ 2:ee820a991b95 178 * @returns temperature for that scale
Michael_ 2:ee820a991b95 179 */
Michael_ 2:ee820a991b95 180 float temperature(char scale='c');
Michael_ 2:ee820a991b95 181
Michael_ 2:ee820a991b95 182 /** This function calculates the ROM checksum and compares it to the
Michael_ 2:ee820a991b95 183 * CRC value stored in ROM[7].
Michael_ 2:ee820a991b95 184 *
Michael_ 2:ee820a991b95 185 * @returns true if the checksum matches, otherwise false.
Michael_ 2:ee820a991b95 186 */
Michael_ 2:ee820a991b95 187 bool ROM_checksum_error();
Michael_ 2:ee820a991b95 188
Michael_ 2:ee820a991b95 189 /** This function calculates the RAM checksum and compares it to the
Michael_ 2:ee820a991b95 190 * CRC value stored in RAM[8].
Michael_ 2:ee820a991b95 191 *
Michael_ 2:ee820a991b95 192 * @returns true if the checksum matches, otherwise false.
Michael_ 2:ee820a991b95 193 */
Michael_ 2:ee820a991b95 194 bool RAM_checksum_error();
Michael_ 2:ee820a991b95 195
Michael_ 2:ee820a991b95 196 /** This function returns the values stored in the temperature
Michael_ 2:ee820a991b95 197 * alarm registers.
Michael_ 2:ee820a991b95 198 *
Michael_ 2:ee820a991b95 199 * @returns a 16 bit integer of TH (upper byte) and TL (lower byte).
Michael_ 2:ee820a991b95 200 */
Michael_ 2:ee820a991b95 201 bool set_configuration_bits(unsigned int resolution);
Michael_ 2:ee820a991b95 202
Michael_ 2:ee820a991b95 203 /** This function sets the temperature resolution for the DS18B20
Michael_ 2:ee820a991b95 204 * in the configuration register.
Michael_ 2:ee820a991b95 205 *
Michael_ 2:ee820a991b95 206 * @param a number between 9 and 12 to specify the resolution
Michael_ 2:ee820a991b95 207 * @returns true if successful
Michael_ 2:ee820a991b95 208 */
Michael_ 2:ee820a991b95 209 int read_scratchpad();
Michael_ 2:ee820a991b95 210
Michael_ 2:ee820a991b95 211 /** This function will store the passed data into the DS1820's RAM.
Michael_ 2:ee820a991b95 212 * Note: It does NOT save the data to the EEPROM for retention
Michael_ 2:ee820a991b95 213 * during cycling the power off and on.
Michael_ 2:ee820a991b95 214 *
Michael_ 2:ee820a991b95 215 * @param a 16 bit integer of TH (upper byte) and TL (lower byte).
Michael_ 2:ee820a991b95 216 */
Michael_ 2:ee820a991b95 217 void write_scratchpad(int data);
Michael_ 2:ee820a991b95 218
Michael_ 2:ee820a991b95 219 /** This function will transfer the TH and TL registers from the
Michael_ 2:ee820a991b95 220 * DS1820's RAM into the EEPROM.
Michael_ 2:ee820a991b95 221 * Note: There is a built in 10ms delay to allow for the
Michael_ 2:ee820a991b95 222 * completion of the EEPROM write cycle.
Michael_ 2:ee820a991b95 223 *
Michael_ 2:ee820a991b95 224 * @param allows the fnction to apply to a specific device or
Michael_ 2:ee820a991b95 225 * to all devices on the 1-Wire bus.
Michael_ 2:ee820a991b95 226 */
Michael_ 2:ee820a991b95 227 void store_scratchpad(devices device=this_device);
Michael_ 2:ee820a991b95 228
Michael_ 2:ee820a991b95 229 /** This function will copy the stored values from the EEPROM
Michael_ 2:ee820a991b95 230 * into the DS1820's RAM locations for TH and TL.
Michael_ 2:ee820a991b95 231 *
Michael_ 2:ee820a991b95 232 * @param allows the function to apply to a specific device or
Michael_ 2:ee820a991b95 233 * to all devices on the 1-Wire bus.
Michael_ 2:ee820a991b95 234 */
Michael_ 2:ee820a991b95 235 int recall_scratchpad(devices device=this_device);
Michael_ 2:ee820a991b95 236
Michael_ 2:ee820a991b95 237 /** This function will return the type of power supply for
Michael_ 2:ee820a991b95 238 * a specific device. It can also be used to query all devices
Michael_ 2:ee820a991b95 239 * looking for any device that is parasite powered.
Michael_ 2:ee820a991b95 240 *
Michael_ 2:ee820a991b95 241 * @returns true if the device (or all devices) are Vcc powered,
Michael_ 2:ee820a991b95 242 * returns false if the device (or ANY device) is parasite powered.
Michael_ 2:ee820a991b95 243 */
Michael_ 2:ee820a991b95 244 bool read_power_supply(devices device=this_device);
Michael_ 2:ee820a991b95 245
Michael_ 2:ee820a991b95 246 private:
Michael_ 2:ee820a991b95 247 bool _parasite_power;
Michael_ 2:ee820a991b95 248 char CRC_byte (char CRC, char byte );
Michael_ 2:ee820a991b95 249 bool onewire_reset();
Michael_ 2:ee820a991b95 250 void match_ROM();
Michael_ 2:ee820a991b95 251 void skip_ROM();
Michael_ 2:ee820a991b95 252 bool search_ROM_routine(char command);
Michael_ 2:ee820a991b95 253 void onewire_bit_out (bool bit_data);
Michael_ 2:ee820a991b95 254 void onewire_byte_out(char data);
Michael_ 2:ee820a991b95 255 bool onewire_bit_in();
Michael_ 2:ee820a991b95 256 char onewire_byte_in();
Michael_ 2:ee820a991b95 257
Michael_ 2:ee820a991b95 258 protected:
Michael_ 2:ee820a991b95 259 DigitalInOut _datapin;
Michael_ 2:ee820a991b95 260 DigitalOut _parasitepin;
Michael_ 2:ee820a991b95 261 };
Michael_ 2:ee820a991b95 262
Michael_ 2:ee820a991b95 263
Michael_ 2:ee820a991b95 264 #endif