ds18b20 for senior design
Dependencies: mbed
Fork of ds18b20_test by
DS1820/DS1820.h@2:b369cd116bf1, 2015-11-17 (annotated)
- Committer:
- jchari
- Date:
- Tue Nov 17 21:55:04 2015 +0000
- Revision:
- 2:b369cd116bf1
- Parent:
- 0:6cb99f312e0e
So committed
Who changed what in which revision?
User | Revision | Line number | New contents of line |
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TuanPM | 0:6cb99f312e0e | 1 | /* mbed DS1820 Library, for the Dallas (Maxim) 1-Wire Digital Thermometer |
TuanPM | 0:6cb99f312e0e | 2 | * Copyright (c) 2010, Michael Hagberg Michael@RedBoxCode.com |
TuanPM | 0:6cb99f312e0e | 3 | * |
TuanPM | 0:6cb99f312e0e | 4 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
TuanPM | 0:6cb99f312e0e | 5 | * of this software and associated documentation files (the "Software"), to deal |
TuanPM | 0:6cb99f312e0e | 6 | * in the Software without restriction, including without limitation the rights |
TuanPM | 0:6cb99f312e0e | 7 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
TuanPM | 0:6cb99f312e0e | 8 | * copies of the Software, and to permit persons to whom the Software is |
TuanPM | 0:6cb99f312e0e | 9 | * furnished to do so, subject to the following conditions: |
TuanPM | 0:6cb99f312e0e | 10 | * |
TuanPM | 0:6cb99f312e0e | 11 | * The above copyright notice and this permission notice shall be included in |
TuanPM | 0:6cb99f312e0e | 12 | * all copies or substantial portions of the Software. |
TuanPM | 0:6cb99f312e0e | 13 | * |
TuanPM | 0:6cb99f312e0e | 14 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
TuanPM | 0:6cb99f312e0e | 15 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
TuanPM | 0:6cb99f312e0e | 16 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
TuanPM | 0:6cb99f312e0e | 17 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
TuanPM | 0:6cb99f312e0e | 18 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
TuanPM | 0:6cb99f312e0e | 19 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
TuanPM | 0:6cb99f312e0e | 20 | * THE SOFTWARE. |
TuanPM | 0:6cb99f312e0e | 21 | */ |
TuanPM | 0:6cb99f312e0e | 22 | |
TuanPM | 0:6cb99f312e0e | 23 | #ifndef MBED_DS1820_H |
TuanPM | 0:6cb99f312e0e | 24 | #define MBED_DS1820_H |
TuanPM | 0:6cb99f312e0e | 25 | |
TuanPM | 0:6cb99f312e0e | 26 | #include "mbed.h" |
TuanPM | 0:6cb99f312e0e | 27 | |
TuanPM | 0:6cb99f312e0e | 28 | // ****** THIS GLOBAL VARIABLES MUST BE DEFINED IN main.cpp |
TuanPM | 0:6cb99f312e0e | 29 | |
TuanPM | 0:6cb99f312e0e | 30 | // Global variables shared between all DS1820 objects |
TuanPM | 0:6cb99f312e0e | 31 | //bool DS1820_done_flag; |
TuanPM | 0:6cb99f312e0e | 32 | //int DS1820_last_descrepancy; |
TuanPM | 0:6cb99f312e0e | 33 | //char DS1820_search_ROM[8]; |
TuanPM | 0:6cb99f312e0e | 34 | |
TuanPM | 0:6cb99f312e0e | 35 | /** DS1820 Dallas 1-Wire Temperature Probe |
TuanPM | 0:6cb99f312e0e | 36 | * |
TuanPM | 0:6cb99f312e0e | 37 | * Example: |
TuanPM | 0:6cb99f312e0e | 38 | * @code |
TuanPM | 0:6cb99f312e0e | 39 | * #include "mbed.h" |
TuanPM | 0:6cb99f312e0e | 40 | * |
TuanPM | 0:6cb99f312e0e | 41 | * #include "TextLCD.h" |
TuanPM | 0:6cb99f312e0e | 42 | * #include "DS1820.h" |
TuanPM | 0:6cb99f312e0e | 43 | * |
TuanPM | 0:6cb99f312e0e | 44 | * TextLCD lcd(p25, p26, p21, p22, p23, p24, TextLCD::LCD16x2); // rs, e, d0-d3, layout |
TuanPM | 0:6cb99f312e0e | 45 | * |
TuanPM | 0:6cb99f312e0e | 46 | * const int MAX_PROBES = 16; |
TuanPM | 0:6cb99f312e0e | 47 | * DS1820* probe[MAX_PROBES]; |
TuanPM | 0:6cb99f312e0e | 48 | * |
TuanPM | 0:6cb99f312e0e | 49 | * int main() { |
TuanPM | 0:6cb99f312e0e | 50 | * int i; |
TuanPM | 0:6cb99f312e0e | 51 | * int devices_found=0; |
TuanPM | 0:6cb99f312e0e | 52 | * // Initialize the probe array to DS1820 objects |
TuanPM | 0:6cb99f312e0e | 53 | * for (i = 0; i < MAX_PROBES; i++) |
TuanPM | 0:6cb99f312e0e | 54 | * probe[i] = new DS1820(p27); |
TuanPM | 0:6cb99f312e0e | 55 | * // Initialize global state variables |
TuanPM | 0:6cb99f312e0e | 56 | * probe[0]->search_ROM_setup(); |
TuanPM | 0:6cb99f312e0e | 57 | * // Loop to find all devices on the data line |
TuanPM | 0:6cb99f312e0e | 58 | * while (probe[devices_found]->search_ROM() and devices_found<MAX_PROBES-1) |
TuanPM | 0:6cb99f312e0e | 59 | * devices_found++; |
TuanPM | 0:6cb99f312e0e | 60 | * // If maximum number of probes are found, |
TuanPM | 0:6cb99f312e0e | 61 | * // bump the counter to include the last array entry |
TuanPM | 0:6cb99f312e0e | 62 | * if (probe[devices_found]->ROM[0] != 0xFF) |
TuanPM | 0:6cb99f312e0e | 63 | * devices_found++; |
TuanPM | 0:6cb99f312e0e | 64 | * |
TuanPM | 0:6cb99f312e0e | 65 | * lcd.cls(); |
TuanPM | 0:6cb99f312e0e | 66 | * if (devices_found==0) |
TuanPM | 0:6cb99f312e0e | 67 | * lcd.printf("No devices found"); |
TuanPM | 0:6cb99f312e0e | 68 | * else { |
TuanPM | 0:6cb99f312e0e | 69 | * while (true) { |
TuanPM | 0:6cb99f312e0e | 70 | * probe[0]->convert_temperature(DS1820::all_devices); |
TuanPM | 0:6cb99f312e0e | 71 | * lcd.cls(); |
TuanPM | 0:6cb99f312e0e | 72 | * for (i=0; i<devices_found; i++) { |
TuanPM | 0:6cb99f312e0e | 73 | * lcd.printf("%3.1f ",probe[i]->temperature('f')); |
TuanPM | 0:6cb99f312e0e | 74 | * } |
TuanPM | 0:6cb99f312e0e | 75 | * } |
TuanPM | 0:6cb99f312e0e | 76 | * } |
TuanPM | 0:6cb99f312e0e | 77 | * } |
TuanPM | 0:6cb99f312e0e | 78 | * @endcode |
TuanPM | 0:6cb99f312e0e | 79 | */ |
TuanPM | 0:6cb99f312e0e | 80 | |
TuanPM | 0:6cb99f312e0e | 81 | class DS1820 { |
TuanPM | 0:6cb99f312e0e | 82 | public: |
TuanPM | 0:6cb99f312e0e | 83 | enum devices{ |
TuanPM | 0:6cb99f312e0e | 84 | this_device, // command applies to only this device |
TuanPM | 0:6cb99f312e0e | 85 | all_devices }; // command applies to all devices |
TuanPM | 0:6cb99f312e0e | 86 | |
TuanPM | 0:6cb99f312e0e | 87 | /** Create a probe object connected to the specified pins |
TuanPM | 0:6cb99f312e0e | 88 | * |
TuanPM | 0:6cb99f312e0e | 89 | * @param data_pin DigitalInOut pin for the data bus |
TuanPM | 0:6cb99f312e0e | 90 | * @param power_pin DigitalOut pin to control the power MOSFET |
TuanPM | 0:6cb99f312e0e | 91 | */ |
TuanPM | 0:6cb99f312e0e | 92 | DS1820(PinName data_pin, PinName power_pin); // Constructor with parasite power pin |
TuanPM | 0:6cb99f312e0e | 93 | |
TuanPM | 0:6cb99f312e0e | 94 | /** Create a probe object connected to the specified pin |
TuanPM | 0:6cb99f312e0e | 95 | * this is used when all probes are externally powered |
TuanPM | 0:6cb99f312e0e | 96 | * |
TuanPM | 0:6cb99f312e0e | 97 | * @param data_pin DigitalInOut pin for the data bus |
TuanPM | 0:6cb99f312e0e | 98 | */ |
TuanPM | 0:6cb99f312e0e | 99 | DS1820(PinName data_pin); |
TuanPM | 0:6cb99f312e0e | 100 | |
TuanPM | 0:6cb99f312e0e | 101 | /** ROM is a copy of the internal DS1820's ROM |
TuanPM | 0:6cb99f312e0e | 102 | * It's created during the search_ROM() or search_alarm() commands |
TuanPM | 0:6cb99f312e0e | 103 | * |
TuanPM | 0:6cb99f312e0e | 104 | * ROM[0] is the Dallas Family Code |
TuanPM | 0:6cb99f312e0e | 105 | * ROM[1] thru ROM[6] is the 48-bit unique serial number |
TuanPM | 0:6cb99f312e0e | 106 | * ROM[7] is the device xCRC |
TuanPM | 0:6cb99f312e0e | 107 | */ |
TuanPM | 0:6cb99f312e0e | 108 | char ROM[8]; |
TuanPM | 0:6cb99f312e0e | 109 | #define FAMILY_CODE ROM[0] |
TuanPM | 0:6cb99f312e0e | 110 | #define FAMILY_CODE_DS1820 0x10 |
TuanPM | 0:6cb99f312e0e | 111 | #define FAMILY_CODE_DS18S20 0x10 |
TuanPM | 0:6cb99f312e0e | 112 | #define FAMILY_CODE_DS18B20 0x28 |
TuanPM | 0:6cb99f312e0e | 113 | |
TuanPM | 0:6cb99f312e0e | 114 | /** RAM is a copy of the internal DS1820's RAM |
TuanPM | 0:6cb99f312e0e | 115 | * It's updated during the read_RAM() command |
TuanPM | 0:6cb99f312e0e | 116 | * which is automaticaly called from any function |
TuanPM | 0:6cb99f312e0e | 117 | * using the RAM values. |
TuanPM | 0:6cb99f312e0e | 118 | */ |
TuanPM | 0:6cb99f312e0e | 119 | char RAM[9]; |
TuanPM | 0:6cb99f312e0e | 120 | |
TuanPM | 0:6cb99f312e0e | 121 | /* This function copies the DS1820's RAM into the object's |
TuanPM | 0:6cb99f312e0e | 122 | * RAM[]. |
TuanPM | 0:6cb99f312e0e | 123 | */ |
TuanPM | 0:6cb99f312e0e | 124 | void read_RAM(); |
TuanPM | 0:6cb99f312e0e | 125 | |
TuanPM | 0:6cb99f312e0e | 126 | /** This routine initializes the global variables used in |
TuanPM | 0:6cb99f312e0e | 127 | * the search_ROM() and search_alarm() funtions. It should |
TuanPM | 0:6cb99f312e0e | 128 | * be called once before looping to find devices. |
TuanPM | 0:6cb99f312e0e | 129 | */ |
TuanPM | 0:6cb99f312e0e | 130 | void search_ROM_setup(); |
TuanPM | 0:6cb99f312e0e | 131 | |
TuanPM | 0:6cb99f312e0e | 132 | /** This routine will search for an unidentified device |
TuanPM | 0:6cb99f312e0e | 133 | * on the bus. It uses the variables in search_ROM_setup |
TuanPM | 0:6cb99f312e0e | 134 | * to remember the pervious ROM address found. |
TuanPM | 0:6cb99f312e0e | 135 | * It will return FALSE if there were no new devices |
TuanPM | 0:6cb99f312e0e | 136 | * discovered on the bus. |
TuanPM | 0:6cb99f312e0e | 137 | */ |
TuanPM | 0:6cb99f312e0e | 138 | bool search_ROM(); |
TuanPM | 0:6cb99f312e0e | 139 | |
TuanPM | 0:6cb99f312e0e | 140 | /** This routine will search for an unidentified device |
TuanPM | 0:6cb99f312e0e | 141 | * which has the temperature alarm bit set. It uses the |
TuanPM | 0:6cb99f312e0e | 142 | * variables in search_ROM_setup to remember the pervious |
TuanPM | 0:6cb99f312e0e | 143 | * ROM address found. It will return FALSE if there were |
TuanPM | 0:6cb99f312e0e | 144 | * no new devices with alarms discovered on the bus. |
TuanPM | 0:6cb99f312e0e | 145 | */ |
TuanPM | 0:6cb99f312e0e | 146 | bool search_alarm(); |
TuanPM | 0:6cb99f312e0e | 147 | |
TuanPM | 0:6cb99f312e0e | 148 | /** This routine will read the ROM (Family code, serial number |
TuanPM | 0:6cb99f312e0e | 149 | * and Checksum) from a dedicated device on the bus. |
TuanPM | 0:6cb99f312e0e | 150 | * |
TuanPM | 0:6cb99f312e0e | 151 | * NOTE: This command can only be used when there is only one |
TuanPM | 0:6cb99f312e0e | 152 | * DS1820 on the bus. If this command is used when there |
TuanPM | 0:6cb99f312e0e | 153 | * is more than one slave present on the bus, a data |
TuanPM | 0:6cb99f312e0e | 154 | * collision will occur when all the DS1820s attempt to |
TuanPM | 0:6cb99f312e0e | 155 | * respond at the same time. |
TuanPM | 0:6cb99f312e0e | 156 | */ |
TuanPM | 0:6cb99f312e0e | 157 | void read_ROM(); |
TuanPM | 0:6cb99f312e0e | 158 | |
TuanPM | 0:6cb99f312e0e | 159 | /** This routine will initiate the temperature conversion within |
TuanPM | 0:6cb99f312e0e | 160 | * a DS1820. There is a built in 750ms delay to allow the |
TuanPM | 0:6cb99f312e0e | 161 | * conversion to complete. |
TuanPM | 0:6cb99f312e0e | 162 | * |
TuanPM | 0:6cb99f312e0e | 163 | * To update all probes on the bus, use a statement such as this: |
TuanPM | 0:6cb99f312e0e | 164 | * probe[0]->convert_temperature(DS1820::all_devices); |
TuanPM | 0:6cb99f312e0e | 165 | * |
TuanPM | 0:6cb99f312e0e | 166 | * @param allows the fnction to apply to a specific device or |
TuanPM | 0:6cb99f312e0e | 167 | * to all devices on the 1-Wire bus. |
TuanPM | 0:6cb99f312e0e | 168 | */ |
TuanPM | 0:6cb99f312e0e | 169 | void convert_temperature(devices device=this_device); |
TuanPM | 0:6cb99f312e0e | 170 | |
TuanPM | 0:6cb99f312e0e | 171 | /** This function will return the probe temperature. This function |
TuanPM | 0:6cb99f312e0e | 172 | * uses the count remainding values to interpolate the temperature |
TuanPM | 0:6cb99f312e0e | 173 | * to about 1/150th of a degree. Whereas the probe is not spec to |
TuanPM | 0:6cb99f312e0e | 174 | * that precision. It does seem to give a smooth reading to the |
TuanPM | 0:6cb99f312e0e | 175 | * tenth of a degree. |
TuanPM | 0:6cb99f312e0e | 176 | * |
TuanPM | 0:6cb99f312e0e | 177 | * @param scale, may be either 'c' or 'f' |
TuanPM | 0:6cb99f312e0e | 178 | * @returns temperature for that scale |
TuanPM | 0:6cb99f312e0e | 179 | */ |
TuanPM | 0:6cb99f312e0e | 180 | float temperature(char scale='c'); |
TuanPM | 0:6cb99f312e0e | 181 | |
TuanPM | 0:6cb99f312e0e | 182 | /** This function calculates the ROM checksum and compares it to the |
TuanPM | 0:6cb99f312e0e | 183 | * xCRC value stored in ROM[7]. |
TuanPM | 0:6cb99f312e0e | 184 | * |
TuanPM | 0:6cb99f312e0e | 185 | * @returns true if the checksum matches, otherwise false. |
TuanPM | 0:6cb99f312e0e | 186 | */ |
TuanPM | 0:6cb99f312e0e | 187 | bool ROM_checksum_error(); |
TuanPM | 0:6cb99f312e0e | 188 | |
TuanPM | 0:6cb99f312e0e | 189 | /** This function calculates the RAM checksum and compares it to the |
TuanPM | 0:6cb99f312e0e | 190 | * xCRC value stored in RAM[8]. |
TuanPM | 0:6cb99f312e0e | 191 | * |
TuanPM | 0:6cb99f312e0e | 192 | * @returns true if the checksum matches, otherwise false. |
TuanPM | 0:6cb99f312e0e | 193 | */ |
TuanPM | 0:6cb99f312e0e | 194 | bool RAM_checksum_error(); |
TuanPM | 0:6cb99f312e0e | 195 | |
TuanPM | 0:6cb99f312e0e | 196 | /** This function returns the values stored in the temperature |
TuanPM | 0:6cb99f312e0e | 197 | * alarm registers. |
TuanPM | 0:6cb99f312e0e | 198 | * |
TuanPM | 0:6cb99f312e0e | 199 | * @returns a 16 bit integer of TH (upper byte) and TL (lower byte). |
TuanPM | 0:6cb99f312e0e | 200 | */ |
TuanPM | 0:6cb99f312e0e | 201 | bool set_configuration_bits(unsigned int resolution); |
TuanPM | 0:6cb99f312e0e | 202 | |
TuanPM | 0:6cb99f312e0e | 203 | /** This function sets the temperature resolution for the DS18B20 |
TuanPM | 0:6cb99f312e0e | 204 | * in the configuration register. |
TuanPM | 0:6cb99f312e0e | 205 | * |
TuanPM | 0:6cb99f312e0e | 206 | * @param a number between 9 and 12 to specify the resolution |
TuanPM | 0:6cb99f312e0e | 207 | * @returns true if successful |
TuanPM | 0:6cb99f312e0e | 208 | */ |
TuanPM | 0:6cb99f312e0e | 209 | int read_scratchpad(); |
TuanPM | 0:6cb99f312e0e | 210 | |
TuanPM | 0:6cb99f312e0e | 211 | /** This function will store the passed data into the DS1820's RAM. |
TuanPM | 0:6cb99f312e0e | 212 | * Note: It does NOT save the data to the EEPROM for retention |
TuanPM | 0:6cb99f312e0e | 213 | * during cycling the power off and on. |
TuanPM | 0:6cb99f312e0e | 214 | * |
TuanPM | 0:6cb99f312e0e | 215 | * @param a 16 bit integer of TH (upper byte) and TL (lower byte). |
TuanPM | 0:6cb99f312e0e | 216 | */ |
TuanPM | 0:6cb99f312e0e | 217 | void write_scratchpad(int data); |
TuanPM | 0:6cb99f312e0e | 218 | |
TuanPM | 0:6cb99f312e0e | 219 | /** This function will transfer the TH and TL registers from the |
TuanPM | 0:6cb99f312e0e | 220 | * DS1820's RAM into the EEPROM. |
TuanPM | 0:6cb99f312e0e | 221 | * Note: There is a built in 10ms delay to allow for the |
TuanPM | 0:6cb99f312e0e | 222 | * completion of the EEPROM write cycle. |
TuanPM | 0:6cb99f312e0e | 223 | * |
TuanPM | 0:6cb99f312e0e | 224 | * @param allows the fnction to apply to a specific device or |
TuanPM | 0:6cb99f312e0e | 225 | * to all devices on the 1-Wire bus. |
TuanPM | 0:6cb99f312e0e | 226 | */ |
TuanPM | 0:6cb99f312e0e | 227 | void store_scratchpad(devices device=this_device); |
TuanPM | 0:6cb99f312e0e | 228 | |
TuanPM | 0:6cb99f312e0e | 229 | /** This function will copy the stored values from the EEPROM |
TuanPM | 0:6cb99f312e0e | 230 | * into the DS1820's RAM locations for TH and TL. |
TuanPM | 0:6cb99f312e0e | 231 | * |
TuanPM | 0:6cb99f312e0e | 232 | * @param allows the function to apply to a specific device or |
TuanPM | 0:6cb99f312e0e | 233 | * to all devices on the 1-Wire bus. |
TuanPM | 0:6cb99f312e0e | 234 | */ |
TuanPM | 0:6cb99f312e0e | 235 | int recall_scratchpad(devices device=this_device); |
TuanPM | 0:6cb99f312e0e | 236 | |
TuanPM | 0:6cb99f312e0e | 237 | /** This function will return the type of power supply for |
TuanPM | 0:6cb99f312e0e | 238 | * a specific device. It can also be used to query all devices |
TuanPM | 0:6cb99f312e0e | 239 | * looking for any device that is parasite powered. |
TuanPM | 0:6cb99f312e0e | 240 | * |
TuanPM | 0:6cb99f312e0e | 241 | * @returns true if the device (or all devices) are Vcc powered, |
TuanPM | 0:6cb99f312e0e | 242 | * returns false if the device (or ANY device) is parasite powered. |
TuanPM | 0:6cb99f312e0e | 243 | */ |
TuanPM | 0:6cb99f312e0e | 244 | bool read_power_supply(devices device=this_device); |
TuanPM | 0:6cb99f312e0e | 245 | private: |
TuanPM | 0:6cb99f312e0e | 246 | bool _parasite_power; |
TuanPM | 0:6cb99f312e0e | 247 | char CRC_byte (char xCRC, char byte ); |
TuanPM | 0:6cb99f312e0e | 248 | bool onewire_reset(); |
TuanPM | 0:6cb99f312e0e | 249 | void match_ROM(); |
TuanPM | 0:6cb99f312e0e | 250 | void skip_ROM(); |
TuanPM | 0:6cb99f312e0e | 251 | bool search_ROM_routine(char command); |
TuanPM | 0:6cb99f312e0e | 252 | void onewire_bit_out (bool bit_data); |
TuanPM | 0:6cb99f312e0e | 253 | void onewire_byte_out(char data); |
TuanPM | 0:6cb99f312e0e | 254 | bool onewire_bit_in(); |
TuanPM | 0:6cb99f312e0e | 255 | char onewire_byte_in(); |
TuanPM | 0:6cb99f312e0e | 256 | |
TuanPM | 0:6cb99f312e0e | 257 | protected: |
TuanPM | 0:6cb99f312e0e | 258 | DigitalInOut _datapin; |
TuanPM | 0:6cb99f312e0e | 259 | DigitalOut _parasitepin; |
TuanPM | 0:6cb99f312e0e | 260 | }; |
TuanPM | 0:6cb99f312e0e | 261 | |
TuanPM | 0:6cb99f312e0e | 262 | |
TuanPM | 0:6cb99f312e0e | 263 | #endif |