Dallas' DS1820 family temperature sensor. For more details see [https://developer.mbed.org/users/hudakz/code/DS1820/wiki/Homepage]
Dependents: BLE_nRF24L01 frdm_serialfgmp gather_sensor_data UltiSaverController ... more
Some programs using the DS1820 library:
Import programDS1820_Hello
Simple DS1820 sensor demo showing how to use the DS1820 library [https://developer.mbed.org/users/hudakz/code/DS1820/]
Import programBLE_nRF24L01
Bluetooth Low Energy (BLE) beacon with nRF24L01(+). Data is received and displayed by Android device (Android app source code is attached).
Examples of use:
Single DS1820 sensor
/* * Single DS1820 sensor GPIO driven * * Note: Don't forget to connect a 4.7k Ohm resistor * between the DS1820's data pin and the +3.3V pin * * ---------------- * | | -----------------------> +3.3V * | MBED BOARD | | * | | | ------ * | +3.3V |--o--| 4.7k |------- * | | ------ | * | | | * | | | * | | | * | | | * | GPIO |--------------------o-----> 1-wire bus/line * | | * | | * | GND |--------------------------> GND * | | * ---------------- * */ #include "mbed.h" #include "DS1820.h" Serial serial(USBTX, USBRX); int main() { DS1820 ds1820(D8); // substitute D8 with actual mbed pin name connected to the DS1820 data pin if(ds1820.begin()) { while(1) { ds1820.startConversion(); // start temperature conversion ThisThread::sleep_for(1000); // let DS1820 complete the temperature conversion serial.printf("temp = %3.1f\r\n", ds1820.read()); // read temperature } } else serial.printf("No DS1820 sensor found!\r\n"); }
Single DS1820 sensor. Data integrity is assured by performing CRC.
/* * Single DS1820 sensor GPIO driven + performing CRC * * Note: Don't forget to connect a 4.7k Ohm resistor * between the DS1820's data pin and the +3.3V pin * * ---------------- * | | -----------------------> +3.3V * | MBED BOARD | | * | | | ------ * | +3.3V |--o--| 4.7k |------- * | | ------ | * | | | * | | | * | | | * | | | * | GPIO |--------------------o-----> 1-wire bus/line * | | * | | * | GND |--------------------------> GND * | | * ---------------- * */ #include "mbed.h" #include "DS1820.h" Serial serial(USBTX, USBRX); int main() { DS1820 ds1820(D8); // substitute D8 with actual mbed pin name connected to the DS1820 data pin float temp = 0; int error = 0; if(ds1820.begin()) { while(1) { ds1820.startConversion(); // start temperature conversion ThisThread::sleep_for(1000); // let DS1820 complete the temperature conversion error = ds1820.read(temp); // read temperature from DS1820 and perform cyclic redundancy check (CRC) switch(error) { case 0: // no errors -> 'temp' contains the value of measured temperature serial.printf("temp = %3.1f\r\n", temp); break; case 1: // no sensor present -> 'temp' is not updated serial.printf("no sensor present\n\r"); break; case 2: // CRC error -> 'temp' is not updated serial.printf("CRC error\r\n"); } } } else serial.printf("No DS1820 sensor found!\r\n"); }
Several DS1820 sensors connected to the same 1-wire bus.
/* * Multiple sensors GPIO driven * * Note: Don't forget to connect a 4.7k Ohm resistor * between the 1-wire bus data line and the +3.3V rail * * ---------------- * | | -----------------------> +3.3V * | MBED BOARD | | * | | | ------ * | +3.3V |--o--| 4.7k |------- * | | ------ | * | | | * | | | * | | | * | | | * | GPIO |--------------------o-----> 1-wire bus/line * | | * | | * | GND |--------------------------> GND * | | * ---------------- * */ #include "mbed.h" #include "DS1820.h" #define MAX_SENSOSRS 32 // max number of DS1820 sensors to be connected to the 1-wire bus (max 256) DS1820* ds1820[MAX_SENSOSRS]; Serial pc(USBTX, USBRX); DigitalOut led(LED1); OneWire oneWire(D8); // substitute D8 with the actual pin name connected to the 1-wire bus int sensorsFound = 0; // counts the actually found DS1820 sensors int main() { pc.printf("\r\n--Starting--\r\n"); //Enumerate (i.e. detect) DS1820 sensors on the 1-wire bus for (sensorsFound = 0; sensorsFound < MAX_SENSOSRS; sensorsFound++) { ds1820[sensorsFound] = new DS1820(&oneWire); if (!ds1820[sensorsFound]->begin()) { delete ds1820[sensorsFound]; break; } } switch (sensorsFound) { case 0: pc.printf("No DS1820 sensor found!\r\n"); return -1; case 1: pc.printf("One DS1820 sensor found.\r\n"); break; default: pc.printf("Found %d DS1820 sensors.\r\n", sensorsFound); } while (1) { pc.printf("----------------\r\n"); for (int i = 0; i < sensorsFound; i++) ds1820[i]->startConversion(); // start temperature conversion from analog to digital ThisThread::sleep_for(1000); // let DS1820 sensors complete the temperature conversion for (int i = 0; i < sensorsFound; i++) { if (ds1820[i]->isPresent()) pc.printf("temp[%d] = %3.1f%cC\r\n", i, ds1820[i]->read(), 176); // read temperature } } }
Several DS1820 sensors connected to the same 1-wire bus. UART is used to implement the bus
/* * Multiple sensors UART driven: * * UART is driving the 1-Wire Bus Master according to Maxim Integrated application note * * https://www.maximintegrated.com/en/design/technical-documents/tutorials/2/214.html * * In addition to the 4.7k Ohm resistor between the 1-wire data bus/line and the +3.3V pin, * a 470 Ohm resistor shall be tied to the UART's tx and rx pin. UART's rx pin is then used * as 1-wire data bus/line. * * ---------------- * | | -----------------------> +3.3V * | MBED BOARD | | * | | | ------ * | +3.3V |--o--| 4.7k |------- * | | ------ | * | | ------ | * | UART TX |-----| 470 |--- | * | | ------ | | * | | | | * | UART RX |----------------o---o-----> 1-wire bus/line * | | * | | * | GND |--------------------------> GND * | | * ---------------- * */ #include "mbed.h" #include "DS1820.h" #define MAX_SENSOSRS 32 // max number of DS1820 sensors to be connected to the 1-wire bus (max 256) DS1820* ds1820[MAX_SENSOSRS]; DigitalOut led(LED1); OneWire oneWire(p9, p10); // LPC1768 (UART Tx pin, UART Rx pin) //OneWire oneWire(PA_0, PA_1); // NUCLE0-F446RE (UART Tx pin, UART Rx pin) int sensorsFound = 0; // counts the actually found DS1820 sensors /** * @brief * @note * @param * @retval */ int main() { printf("\r\n--Starting--\r\n"); //Enumerate (i.e. detect) DS1820 sensors on the 1-wire bus for (sensorsFound = 0; sensorsFound < MAX_SENSOSRS; sensorsFound++) { ds1820[sensorsFound] = new DS1820(&oneWire); if (!ds1820[sensorsFound]->begin()) { delete ds1820[sensorsFound]; break; } } switch (sensorsFound) { case 0: printf("No DS1820 sensor found!\r\n"); return -1; case 1: printf("One DS1820 sensor found.\r\n"); break; default: printf("Found %d DS1820 sensors.\r\n", sensorsFound); } while (1) { led = !led; printf("----------------\r\n"); for (int i = 0; i < sensorsFound; i++) ds1820[i]->startConversion(); // start temperature conversion from analog to digital #if (MBED_MAJOR_VERSION > 5) ThisThread::sleep_for(1s); #else wait(1); #endif for (int i = 0; i < sensorsFound; i++) { if (ds1820[i]->isPresent()) printf("temp[%d] = %3.1f%cC\r\n", i, ds1820[i]->read(), 176); // read temperature } } }
DS1820.cpp@24:d683d826dccd, 2020-12-28 (annotated)
- Committer:
- hudakz
- Date:
- Mon Dec 28 21:15:27 2020 +0000
- Revision:
- 24:d683d826dccd
- Parent:
- 23:74a4ff420541
DS1820: Added 1-wire bus implementation over UART.
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
hudakz | 3:a250babd0a9f | 1 | /* |
hudakz | 3:a250babd0a9f | 2 | * Dallas' DS1820 family temperature sensor. |
hudakz | 3:a250babd0a9f | 3 | * This library depends on the OneWire library (Dallas' 1-Wire bus protocol implementation) |
hudakz | 6:518950e436be | 4 | * available at <http://developer.mbed.org/users/hudakz/code/OneWire/> |
hudakz | 3:a250babd0a9f | 5 | * |
hudakz | 3:a250babd0a9f | 6 | * Example of use: |
hudakz | 24:d683d826dccd | 7 | * |
hudakz | 20:98c261bcb399 | 8 | * Single sensor. |
hudakz | 6:518950e436be | 9 | * |
hudakz | 20:98c261bcb399 | 10 | * #include "mbed.h" |
hudakz | 20:98c261bcb399 | 11 | * #include "DS1820.h" |
hudakz | 24:d683d826dccd | 12 | * |
hudakz | 20:98c261bcb399 | 13 | * Serial pc(USBTX, USBRX); |
hudakz | 20:98c261bcb399 | 14 | * DigitalOut led(LED1); |
hudakz | 20:98c261bcb399 | 15 | * OneWire oneWire(D8); // substitute D8 with actual mbed pin name connected 1-wire bus |
hudakz | 20:98c261bcb399 | 16 | * float temp = 0; |
hudakz | 20:98c261bcb399 | 17 | * int result = 0; |
hudakz | 24:d683d826dccd | 18 | * |
hudakz | 20:98c261bcb399 | 19 | * int main() |
hudakz | 20:98c261bcb399 | 20 | * { |
hudakz | 20:98c261bcb399 | 21 | * pc.printf("\r\n--Starting--\r\n"); |
hudakz | 20:98c261bcb399 | 22 | * if (ds1820.begin()) { |
hudakz | 20:98c261bcb399 | 23 | * while (1) { |
hudakz | 20:98c261bcb399 | 24 | * ds1820.startConversion(); // start temperature conversion from analog to digital |
hudakz | 24:d683d826dccd | 25 | * ThisThread::sleep_for(1000ms);// let DS1820 complete the temperature conversion |
hudakz | 24:d683d826dccd | 26 | * result = ds1820.read(temp); // read temperature from DS1820 and perform cyclic redundancy check (CRC) |
hudakz | 20:98c261bcb399 | 27 | * switch (result) { |
hudakz | 24:d683d826dccd | 28 | * case 0: // no errors -> 'temp' contains the value of measured temperature |
hudakz | 20:98c261bcb399 | 29 | * pc.printf("temp = %3.1f%cC\r\n", temp, 176); |
hudakz | 20:98c261bcb399 | 30 | * break; |
hudakz | 24:d683d826dccd | 31 | * |
hudakz | 24:d683d826dccd | 32 | * case 1: // no sensor present -> 'temp' is not updated |
hudakz | 20:98c261bcb399 | 33 | * pc.printf("no sensor present\n\r"); |
hudakz | 20:98c261bcb399 | 34 | * break; |
hudakz | 24:d683d826dccd | 35 | * |
hudakz | 24:d683d826dccd | 36 | * case 2: // CRC error -> 'temp' is not updated |
hudakz | 20:98c261bcb399 | 37 | * pc.printf("CRC error\r\n"); |
hudakz | 20:98c261bcb399 | 38 | * } |
hudakz | 24:d683d826dccd | 39 | * |
hudakz | 20:98c261bcb399 | 40 | * led = !led; |
hudakz | 20:98c261bcb399 | 41 | * } |
hudakz | 20:98c261bcb399 | 42 | * } |
hudakz | 20:98c261bcb399 | 43 | * else |
hudakz | 20:98c261bcb399 | 44 | * pc.printf("No DS1820 sensor found!\r\n"); |
hudakz | 20:98c261bcb399 | 45 | * } |
hudakz | 24:d683d826dccd | 46 | * |
hudakz | 24:d683d826dccd | 47 | * |
hudakz | 20:98c261bcb399 | 48 | * More sensors connected to the same 1-wire bus. |
hudakz | 24:d683d826dccd | 49 | * |
hudakz | 20:98c261bcb399 | 50 | * #include "mbed.h" |
hudakz | 20:98c261bcb399 | 51 | * #include "DS1820.h" |
hudakz | 24:d683d826dccd | 52 | * |
hudakz | 20:98c261bcb399 | 53 | * #define SENSORS_COUNT 64 // number of DS1820 sensors to be connected to the 1-wire bus (max 256) |
hudakz | 24:d683d826dccd | 54 | * |
hudakz | 20:98c261bcb399 | 55 | * Serial pc(USBTX, USBRX); |
hudakz | 20:98c261bcb399 | 56 | * DigitalOut led(LED1); |
hudakz | 20:98c261bcb399 | 57 | * OneWire oneWire(D8); // substitute D8 with actual mbed pin name connected to the DS1820 data pin |
hudakz | 20:98c261bcb399 | 58 | * DS1820* ds1820[SENSORS_COUNT]; |
hudakz | 20:98c261bcb399 | 59 | * int sensors_found = 0; // counts the actually found DS1820 sensors |
hudakz | 20:98c261bcb399 | 60 | * float temp = 0; |
hudakz | 20:98c261bcb399 | 61 | * int result = 0; |
hudakz | 24:d683d826dccd | 62 | * |
hudakz | 3:a250babd0a9f | 63 | * int main() { |
hudakz | 20:98c261bcb399 | 64 | * int i = 0; |
hudakz | 24:d683d826dccd | 65 | * |
hudakz | 20:98c261bcb399 | 66 | * pc.printf("\r\n Starting \r\n"); |
hudakz | 20:98c261bcb399 | 67 | * //Enumerate (i.e. detect) DS1820 sensors on the 1-wire bus |
hudakz | 20:98c261bcb399 | 68 | * for(i = 0; i < SENSORS_COUNT; i++) { |
hudakz | 20:98c261bcb399 | 69 | * ds1820[i] = new DS1820(&oneWire); |
hudakz | 20:98c261bcb399 | 70 | * if(!ds1820[i]->begin()) { |
hudakz | 20:98c261bcb399 | 71 | * delete ds1820[i]; |
hudakz | 20:98c261bcb399 | 72 | * break; |
hudakz | 20:98c261bcb399 | 73 | * } |
hudakz | 20:98c261bcb399 | 74 | * } |
hudakz | 24:d683d826dccd | 75 | * |
hudakz | 20:98c261bcb399 | 76 | * sensors_found = i; |
hudakz | 24:d683d826dccd | 77 | * |
hudakz | 20:98c261bcb399 | 78 | * if (sensors_found == 0) { |
hudakz | 20:98c261bcb399 | 79 | * pc.printf("No DS1820 sensor found!\r\n"); |
hudakz | 20:98c261bcb399 | 80 | * return -1; |
hudakz | 20:98c261bcb399 | 81 | * } |
hudakz | 20:98c261bcb399 | 82 | * else |
hudakz | 20:98c261bcb399 | 83 | * pc.printf("Found %d sensors.\r\n", sensors_found); |
hudakz | 24:d683d826dccd | 84 | * |
hudakz | 20:98c261bcb399 | 85 | * while(1) { |
hudakz | 20:98c261bcb399 | 86 | * pc.printf("-------------------\r\n"); |
hudakz | 20:98c261bcb399 | 87 | * for(i = 0; i < sensors_found; i++) |
hudakz | 24:d683d826dccd | 88 | * ds1820[i]->startConversion(); // start temperature conversion from analog to digital |
hudakz | 24:d683d826dccd | 89 | * ThisThread::sleep_for(1000ms); // let DS1820s complete the temperature conversion |
hudakz | 20:98c261bcb399 | 90 | * for(int i = 0; i < sensors_found; i++) { |
hudakz | 20:98c261bcb399 | 91 | * if(ds1820[i]->isPresent()) |
hudakz | 20:98c261bcb399 | 92 | * pc.printf("temp[%d] = %3.1f%cC\r\n", i, ds1820[i]->read(), 176); // read temperature |
hudakz | 20:98c261bcb399 | 93 | * } |
hudakz | 20:98c261bcb399 | 94 | * } |
hudakz | 3:a250babd0a9f | 95 | * } |
hudakz | 24:d683d826dccd | 96 | * |
hudakz | 3:a250babd0a9f | 97 | */ |
hudakz | 0:433af64321d5 | 98 | #include "DS1820.h" |
hudakz | 0:433af64321d5 | 99 | |
hudakz | 24:d683d826dccd | 100 | //#define DEBUG 1 |
hudakz | 20:98c261bcb399 | 101 | |
hudakz | 20:98c261bcb399 | 102 | //* Initializing static members |
hudakz | 24:d683d826dccd | 103 | uint8_t DS1820:: _lastAddr[8] = { 0, 0, 0, 0, 0, 0, 0, 0 }; |
hudakz | 24:d683d826dccd | 104 | |
hudakz | 20:98c261bcb399 | 105 | /** |
hudakz | 20:98c261bcb399 | 106 | * @brief Constructs a generic DS1820 sensor |
hudakz | 20:98c261bcb399 | 107 | * @note begin() must be called to detect and initialize the actual model |
hudakz | 24:d683d826dccd | 108 | * @param gpioPin: Name of the GPIO pin |
hudakz | 20:98c261bcb399 | 109 | * @retval |
hudakz | 20:98c261bcb399 | 110 | */ |
hudakz | 24:d683d826dccd | 111 | DS1820::DS1820(PinName gpioPin, int samplePoint_us /*=13*/ ) |
hudakz | 24:d683d826dccd | 112 | { |
hudakz | 24:d683d826dccd | 113 | _oneWire = new OneWire(gpioPin, samplePoint_us); |
hudakz | 24:d683d826dccd | 114 | _present = false; |
hudakz | 24:d683d826dccd | 115 | _model_s = false; |
hudakz | 24:d683d826dccd | 116 | } |
hudakz | 24:d683d826dccd | 117 | |
hudakz | 24:d683d826dccd | 118 | /** |
hudakz | 24:d683d826dccd | 119 | * @brief Constructs a generic DS1820 sensor |
hudakz | 24:d683d826dccd | 120 | * @note begin() must be called to detect and initialize the actual model |
hudakz | 24:d683d826dccd | 121 | * @param txPin: UART's Tx pin |
hudakz | 24:d683d826dccd | 122 | * @param rxPin: UART's Rx pin |
hudakz | 24:d683d826dccd | 123 | * @retval |
hudakz | 24:d683d826dccd | 124 | */ |
hudakz | 24:d683d826dccd | 125 | DS1820::DS1820(PinName txPin, PinName rxPin) |
hudakz | 24:d683d826dccd | 126 | { |
hudakz | 24:d683d826dccd | 127 | _oneWire = new OneWire(txPin, rxPin); |
hudakz | 24:d683d826dccd | 128 | _present = false; |
hudakz | 24:d683d826dccd | 129 | _model_s = false; |
hudakz | 20:98c261bcb399 | 130 | } |
hudakz | 0:433af64321d5 | 131 | |
hudakz | 0:433af64321d5 | 132 | /** |
hudakz | 0:433af64321d5 | 133 | * @brief Constructs a generic DS1820 sensor |
hudakz | 0:433af64321d5 | 134 | * @note begin() must be called to detect and initialize the actual model |
hudakz | 3:a250babd0a9f | 135 | * @param pin: Name of data pin |
hudakz | 0:433af64321d5 | 136 | * @retval |
hudakz | 0:433af64321d5 | 137 | */ |
hudakz | 24:d683d826dccd | 138 | DS1820::DS1820(OneWire* oneWire) : |
hudakz | 24:d683d826dccd | 139 | _oneWire(oneWire) |
hudakz | 24:d683d826dccd | 140 | { |
hudakz | 24:d683d826dccd | 141 | _present = false; |
hudakz | 24:d683d826dccd | 142 | _model_s = false; |
hudakz | 0:433af64321d5 | 143 | } |
hudakz | 0:433af64321d5 | 144 | |
hudakz | 0:433af64321d5 | 145 | /** |
hudakz | 0:433af64321d5 | 146 | * @brief Detects and initializes the actual DS1820 model |
hudakz | 0:433af64321d5 | 147 | * @note |
hudakz | 0:433af64321d5 | 148 | * @param |
hudakz | 0:433af64321d5 | 149 | * @retval true: if a DS1820 family sensor was detected and initialized |
hudakz | 0:433af64321d5 | 150 | false: otherwise |
hudakz | 0:433af64321d5 | 151 | */ |
hudakz | 24:d683d826dccd | 152 | bool DS1820::begin(void) |
hudakz | 24:d683d826dccd | 153 | { |
hudakz | 20:98c261bcb399 | 154 | #if DEBUG |
hudakz | 20:98c261bcb399 | 155 | printf("lastAddr ="); |
hudakz | 24:d683d826dccd | 156 | for (uint8_t i = 0; i < 8; i++) { |
hudakz | 20:98c261bcb399 | 157 | printf(" %x", lastAddr[i]); |
hudakz | 20:98c261bcb399 | 158 | } |
hudakz | 24:d683d826dccd | 159 | |
hudakz | 20:98c261bcb399 | 160 | printf("\r\n"); |
hudakz | 20:98c261bcb399 | 161 | #endif |
hudakz | 24:d683d826dccd | 162 | if (!_oneWire->search(_lastAddr)) |
hudakz | 24:d683d826dccd | 163 | { |
hudakz | 0:433af64321d5 | 164 | #if DEBUG |
hudakz | 17:9ff584b9809f | 165 | printf("No addresses.\r\n"); |
hudakz | 0:433af64321d5 | 166 | #endif |
hudakz | 24:d683d826dccd | 167 | _oneWire->reset_search(); |
hudakz | 24:d683d826dccd | 168 | #if MBED_MAJOR_VERSION == 2 |
hudakz | 24:d683d826dccd | 169 | wait_ms(250); |
hudakz | 24:d683d826dccd | 170 | #else |
hudakz | 24:d683d826dccd | 171 | ThisThread::sleep_for(250ms); |
hudakz | 24:d683d826dccd | 172 | #endif |
hudakz | 0:433af64321d5 | 173 | return false; |
hudakz | 0:433af64321d5 | 174 | } |
hudakz | 24:d683d826dccd | 175 | |
hudakz | 20:98c261bcb399 | 176 | for (int i = 0; i < 8; i++) |
hudakz | 24:d683d826dccd | 177 | _addr[i] = _lastAddr[i]; |
hudakz | 0:433af64321d5 | 178 | |
hudakz | 0:433af64321d5 | 179 | #if DEBUG |
hudakz | 17:9ff584b9809f | 180 | printf("ROM ="); |
hudakz | 24:d683d826dccd | 181 | for (uint8_t i = 0; i < 8; i++) { |
hudakz | 17:9ff584b9809f | 182 | printf(" %x", addr[i]); |
hudakz | 0:433af64321d5 | 183 | } |
hudakz | 24:d683d826dccd | 184 | |
hudakz | 17:9ff584b9809f | 185 | printf("\r\n"); |
hudakz | 0:433af64321d5 | 186 | #endif |
hudakz | 24:d683d826dccd | 187 | if (OneWire::crc8(_addr, 7) == _addr[7]) { |
hudakz | 24:d683d826dccd | 188 | _present = true; |
hudakz | 0:433af64321d5 | 189 | |
hudakz | 0:433af64321d5 | 190 | // the first ROM byte indicates which chip |
hudakz | 24:d683d826dccd | 191 | switch (_addr[0]) { |
hudakz | 24:d683d826dccd | 192 | case 0x10: |
hudakz | 24:d683d826dccd | 193 | _model_s = true; |
hudakz | 24:d683d826dccd | 194 | #if DEBUG |
hudakz | 24:d683d826dccd | 195 | printf("DS18S20 or old DS1820\r\n"); |
hudakz | 24:d683d826dccd | 196 | #endif |
hudakz | 24:d683d826dccd | 197 | break; |
hudakz | 0:433af64321d5 | 198 | |
hudakz | 24:d683d826dccd | 199 | case 0x28: |
hudakz | 24:d683d826dccd | 200 | _model_s = false; |
hudakz | 24:d683d826dccd | 201 | #if DEBUG |
hudakz | 24:d683d826dccd | 202 | printf("DS18B20\r\n"); |
hudakz | 24:d683d826dccd | 203 | #endif |
hudakz | 24:d683d826dccd | 204 | break; |
hudakz | 0:433af64321d5 | 205 | |
hudakz | 24:d683d826dccd | 206 | case 0x22: |
hudakz | 24:d683d826dccd | 207 | _model_s = false; |
hudakz | 24:d683d826dccd | 208 | #if DEBUG |
hudakz | 24:d683d826dccd | 209 | printf("DS1822\r\n"); |
hudakz | 24:d683d826dccd | 210 | #endif |
hudakz | 24:d683d826dccd | 211 | break; |
hudakz | 0:433af64321d5 | 212 | |
hudakz | 24:d683d826dccd | 213 | default: |
hudakz | 24:d683d826dccd | 214 | _present = false; |
hudakz | 24:d683d826dccd | 215 | #if DEBUG |
hudakz | 24:d683d826dccd | 216 | printf("Device doesn't belong to the DS1820 family\r\n"); |
hudakz | 24:d683d826dccd | 217 | #endif |
hudakz | 24:d683d826dccd | 218 | return false; |
hudakz | 0:433af64321d5 | 219 | } |
hudakz | 24:d683d826dccd | 220 | |
hudakz | 0:433af64321d5 | 221 | return true; |
hudakz | 0:433af64321d5 | 222 | } |
hudakz | 24:d683d826dccd | 223 | else |
hudakz | 24:d683d826dccd | 224 | { |
hudakz | 24:d683d826dccd | 225 | #if DEBUG |
hudakz | 17:9ff584b9809f | 226 | printf("Invalid CRC!\r\n"); |
hudakz | 24:d683d826dccd | 227 | #endif |
hudakz | 0:433af64321d5 | 228 | return false; |
hudakz | 0:433af64321d5 | 229 | } |
hudakz | 0:433af64321d5 | 230 | } |
hudakz | 0:433af64321d5 | 231 | |
hudakz | 0:433af64321d5 | 232 | /** |
hudakz | 8:8dfdd1603e4d | 233 | * @brief Informs about presence of a DS1820 sensor. |
hudakz | 8:8dfdd1603e4d | 234 | * @note begin() shall be called before using this function |
hudakz | 24:d683d826dccd | 235 | * if a generic DS1820 instance was created by the user. |
hudakz | 8:8dfdd1603e4d | 236 | * No need to call begin() for a specific DS1820 instance. |
hudakz | 8:8dfdd1603e4d | 237 | * @param |
hudakz | 8:8dfdd1603e4d | 238 | * @retval true: when a DS1820 sensor is present |
hudakz | 8:8dfdd1603e4d | 239 | * false: otherwise |
hudakz | 8:8dfdd1603e4d | 240 | */ |
hudakz | 24:d683d826dccd | 241 | bool DS1820::isPresent(void) |
hudakz | 24:d683d826dccd | 242 | { |
hudakz | 24:d683d826dccd | 243 | return _present; |
hudakz | 8:8dfdd1603e4d | 244 | } |
hudakz | 8:8dfdd1603e4d | 245 | |
hudakz | 8:8dfdd1603e4d | 246 | /** |
hudakz | 6:518950e436be | 247 | * @brief Sets temperature-to-digital conversion resolution. |
hudakz | 4:adf4e7972d73 | 248 | * @note The configuration register allows the user to set the resolution |
hudakz | 6:518950e436be | 249 | * of the temperature-to-digital conversion to 9, 10, 11, or 12 bits. |
hudakz | 6:518950e436be | 250 | * Defaults to 12-bit resolution for DS18B20. |
hudakz | 6:518950e436be | 251 | * DS18S20 allows only 9-bit resolution. |
hudakz | 6:518950e436be | 252 | * @param res: Resolution of the temperature-to-digital conversion in bits. |
hudakz | 4:adf4e7972d73 | 253 | * @retval |
hudakz | 4:adf4e7972d73 | 254 | */ |
hudakz | 24:d683d826dccd | 255 | void DS1820::setResolution(uint8_t res) |
hudakz | 24:d683d826dccd | 256 | { |
hudakz | 4:adf4e7972d73 | 257 | // keep resolution within limits |
hudakz | 24:d683d826dccd | 258 | |
hudakz | 24:d683d826dccd | 259 | if (res > 12) |
hudakz | 4:adf4e7972d73 | 260 | res = 12; |
hudakz | 24:d683d826dccd | 261 | if (res < 9) |
hudakz | 24:d683d826dccd | 262 | res = 9; |
hudakz | 24:d683d826dccd | 263 | if (_model_s) |
hudakz | 4:adf4e7972d73 | 264 | res = 9; |
hudakz | 24:d683d826dccd | 265 | |
hudakz | 24:d683d826dccd | 266 | _oneWire->reset(); |
hudakz | 24:d683d826dccd | 267 | _oneWire->select(_addr); |
hudakz | 24:d683d826dccd | 268 | _oneWire->write_byte(0xBE); // to read Scratchpad |
hudakz | 24:d683d826dccd | 269 | for (uint8_t i = 0; i < 9; i++) // read Scratchpad bytes |
hudakz | 24:d683d826dccd | 270 | _data[i] = _oneWire->read_byte(); |
hudakz | 4:adf4e7972d73 | 271 | |
hudakz | 24:d683d826dccd | 272 | _data[4] |= (res - 9) << 5; // update configuration byte (set resolution) |
hudakz | 24:d683d826dccd | 273 | _oneWire->reset(); |
hudakz | 24:d683d826dccd | 274 | _oneWire->select(_addr); |
hudakz | 24:d683d826dccd | 275 | _oneWire->write_byte(0x4E); // to write into Scratchpad |
hudakz | 24:d683d826dccd | 276 | for (uint8_t i = 2; i < 5; i++) // write three bytes (2nd, 3rd, 4th) into Scratchpad |
hudakz | 24:d683d826dccd | 277 | _oneWire->write_byte(_data[i]); |
hudakz | 4:adf4e7972d73 | 278 | } |
hudakz | 4:adf4e7972d73 | 279 | |
hudakz | 4:adf4e7972d73 | 280 | /** |
hudakz | 0:433af64321d5 | 281 | * @brief Starts temperature conversion |
hudakz | 6:518950e436be | 282 | * @note The time to complete the converion depends on the selected resolution: |
hudakz | 6:518950e436be | 283 | * 9-bit resolution -> max conversion time = 93.75ms |
hudakz | 6:518950e436be | 284 | * 10-bit resolution -> max conversion time = 187.5ms |
hudakz | 6:518950e436be | 285 | * 11-bit resolution -> max conversion time = 375ms |
hudakz | 6:518950e436be | 286 | * 12-bit resolution -> max conversion time = 750ms |
hudakz | 0:433af64321d5 | 287 | * @param |
hudakz | 0:433af64321d5 | 288 | * @retval |
hudakz | 0:433af64321d5 | 289 | */ |
hudakz | 24:d683d826dccd | 290 | void DS1820::startConversion(void) |
hudakz | 24:d683d826dccd | 291 | { |
hudakz | 24:d683d826dccd | 292 | if (_present) { |
hudakz | 24:d683d826dccd | 293 | _oneWire->reset(); |
hudakz | 24:d683d826dccd | 294 | _oneWire->select(_addr); |
hudakz | 24:d683d826dccd | 295 | _oneWire->write_byte(0x44); //start temperature conversion |
hudakz | 0:433af64321d5 | 296 | } |
hudakz | 0:433af64321d5 | 297 | } |
hudakz | 0:433af64321d5 | 298 | |
hudakz | 0:433af64321d5 | 299 | /** |
hudakz | 6:518950e436be | 300 | * @brief Reads temperature from the chip's Scratchpad |
hudakz | 0:433af64321d5 | 301 | * @note |
hudakz | 0:433af64321d5 | 302 | * @param |
hudakz | 0:433af64321d5 | 303 | * @retval Floating point temperature value |
hudakz | 0:433af64321d5 | 304 | */ |
hudakz | 24:d683d826dccd | 305 | float DS1820::read(void) |
hudakz | 24:d683d826dccd | 306 | { |
hudakz | 24:d683d826dccd | 307 | if (_present) { |
hudakz | 24:d683d826dccd | 308 | _oneWire->reset(); |
hudakz | 24:d683d826dccd | 309 | _oneWire->select(_addr); |
hudakz | 24:d683d826dccd | 310 | _oneWire->write_byte(0xBE); // to read Scratchpad |
hudakz | 24:d683d826dccd | 311 | for (uint8_t i = 0; i < 9; i++) // reading scratchpad registers |
hudakz | 24:d683d826dccd | 312 | _data[i] = _oneWire->read_byte(); |
hudakz | 0:433af64321d5 | 313 | |
hudakz | 6:518950e436be | 314 | // Convert the raw bytes to a 16-bit unsigned value |
hudakz | 24:d683d826dccd | 315 | uint16_t* p_word = reinterpret_cast < uint16_t * > (&_data[0]); |
hudakz | 0:433af64321d5 | 316 | |
hudakz | 0:433af64321d5 | 317 | #if DEBUG |
hudakz | 17:9ff584b9809f | 318 | printf("raw = %#x\r\n", *p_word); |
hudakz | 24:d683d826dccd | 319 | #endif |
hudakz | 24:d683d826dccd | 320 | if (_model_s) { |
hudakz | 6:518950e436be | 321 | *p_word = *p_word << 3; // 9-bit resolution |
hudakz | 24:d683d826dccd | 322 | if (_data[7] == 0x10) { |
hudakz | 0:433af64321d5 | 323 | |
hudakz | 6:518950e436be | 324 | // "count remain" gives full 12-bit resolution |
hudakz | 24:d683d826dccd | 325 | *p_word = (*p_word & 0xFFF0) + 12 - _data[6]; |
hudakz | 0:433af64321d5 | 326 | } |
hudakz | 0:433af64321d5 | 327 | } |
hudakz | 0:433af64321d5 | 328 | else { |
hudakz | 24:d683d826dccd | 329 | uint8_t cfg = (_data[4] & 0x60); // default 12-bit resolution |
hudakz | 24:d683d826dccd | 330 | |
hudakz | 4:adf4e7972d73 | 331 | // at lower resolution, the low bits are undefined, so let's clear them |
hudakz | 24:d683d826dccd | 332 | if (cfg == 0x00) |
hudakz | 6:518950e436be | 333 | *p_word = *p_word &~7; // 9-bit resolution |
hudakz | 0:433af64321d5 | 334 | else |
hudakz | 24:d683d826dccd | 335 | if (cfg == 0x20) |
hudakz | 6:518950e436be | 336 | *p_word = *p_word &~3; // 10-bit resolution |
hudakz | 0:433af64321d5 | 337 | else |
hudakz | 24:d683d826dccd | 338 | if (cfg == 0x40) |
hudakz | 6:518950e436be | 339 | *p_word = *p_word &~1; // 11-bit resolution |
hudakz | 0:433af64321d5 | 340 | } |
hudakz | 6:518950e436be | 341 | |
hudakz | 6:518950e436be | 342 | // Convert the raw bytes to a 16-bit signed fixed point value : |
hudakz | 6:518950e436be | 343 | // 1 sign bit, 7 integer bits, 8 fractional bits (two’s compliment |
hudakz | 6:518950e436be | 344 | // and the LSB of the 16-bit binary number represents 1/256th of a unit). |
hudakz | 6:518950e436be | 345 | *p_word = *p_word << 4; |
hudakz | 24:d683d826dccd | 346 | |
hudakz | 6:518950e436be | 347 | // Convert to floating point value |
hudakz | 6:518950e436be | 348 | return(toFloat(*p_word)); |
hudakz | 0:433af64321d5 | 349 | } |
hudakz | 0:433af64321d5 | 350 | else |
hudakz | 0:433af64321d5 | 351 | return 0; |
hudakz | 0:433af64321d5 | 352 | } |
hudakz | 0:433af64321d5 | 353 | |
hudakz | 0:433af64321d5 | 354 | /** |
hudakz | 13:b593a82ce790 | 355 | * @brief Reads temperature from chip's scratchpad. |
hudakz | 13:b593a82ce790 | 356 | * @note Verifies data integrity by calculating cyclic redundancy check (CRC). |
hudakz | 13:b593a82ce790 | 357 | * If the calculated CRC dosn't match the one stored in chip's scratchpad register |
hudakz | 13:b593a82ce790 | 358 | * the temperature variable is not updated and CRC error code is returned. |
hudakz | 13:b593a82ce790 | 359 | * @param temp: The temperature variable to be updated by this routine. |
hudakz | 13:b593a82ce790 | 360 | * (It's passed as reference to floating point.) |
hudakz | 13:b593a82ce790 | 361 | * @retval error code: |
hudakz | 13:b593a82ce790 | 362 | * 0 - no errors ('temp' contains the temperature measured) |
hudakz | 13:b593a82ce790 | 363 | * 1 - sensor not present ('temp' is not updated) |
hudakz | 13:b593a82ce790 | 364 | * 2 - CRC error ('temp' is not updated) |
hudakz | 13:b593a82ce790 | 365 | */ |
hudakz | 24:d683d826dccd | 366 | uint8_t DS1820::read(float& temp) |
hudakz | 24:d683d826dccd | 367 | { |
hudakz | 24:d683d826dccd | 368 | if (_present) { |
hudakz | 24:d683d826dccd | 369 | _oneWire->reset(); |
hudakz | 24:d683d826dccd | 370 | _oneWire->select(_addr); |
hudakz | 24:d683d826dccd | 371 | _oneWire->write_byte(0xBE); // to read Scratchpad |
hudakz | 24:d683d826dccd | 372 | for (uint8_t i = 0; i < 9; i++) // reading scratchpad registers |
hudakz | 24:d683d826dccd | 373 | _data[i] = _oneWire->read_byte(); |
hudakz | 13:b593a82ce790 | 374 | |
hudakz | 24:d683d826dccd | 375 | if (_oneWire->crc8(_data, 8) != _data[8]) // if calculated CRC does not match the stored one |
hudakz | 17:9ff584b9809f | 376 | { |
hudakz | 17:9ff584b9809f | 377 | #if DEBUG |
hudakz | 24:d683d826dccd | 378 | for (uint8_t i = 0; i < 9; i++) |
hudakz | 17:9ff584b9809f | 379 | printf("data[%d]=0x%.2x\r\n", i, data[i]); |
hudakz | 24:d683d826dccd | 380 | #endif |
hudakz | 13:b593a82ce790 | 381 | return 2; // return with CRC error |
hudakz | 17:9ff584b9809f | 382 | } |
hudakz | 13:b593a82ce790 | 383 | |
hudakz | 13:b593a82ce790 | 384 | // Convert the raw bytes to a 16bit unsigned value |
hudakz | 24:d683d826dccd | 385 | uint16_t* p_word = reinterpret_cast < uint16_t * > (&_data[0]); |
hudakz | 13:b593a82ce790 | 386 | |
hudakz | 13:b593a82ce790 | 387 | #if DEBUG |
hudakz | 17:9ff584b9809f | 388 | printf("raw = %#x\r\n", *p_word); |
hudakz | 13:b593a82ce790 | 389 | #endif |
hudakz | 24:d683d826dccd | 390 | if (_model_s) { |
hudakz | 24:d683d826dccd | 391 | *p_word = *p_word << 3; // 9 bit resolution, max conversion time = 750ms |
hudakz | 24:d683d826dccd | 392 | if (_data[7] == 0x10) { |
hudakz | 13:b593a82ce790 | 393 | |
hudakz | 13:b593a82ce790 | 394 | // "count remain" gives full 12 bit resolution |
hudakz | 24:d683d826dccd | 395 | *p_word = (*p_word & 0xFFF0) + 12 - _data[6]; |
hudakz | 13:b593a82ce790 | 396 | } |
hudakz | 13:b593a82ce790 | 397 | |
hudakz | 13:b593a82ce790 | 398 | // Convert the raw bytes to a 16bit signed fixed point value : |
hudakz | 13:b593a82ce790 | 399 | // 1 sign bit, 7 integer bits, 8 fractional bits (two's compliment |
hudakz | 13:b593a82ce790 | 400 | // and the LSB of the 16bit binary number represents 1/256th of a unit). |
hudakz | 13:b593a82ce790 | 401 | *p_word = *p_word << 4; |
hudakz | 24:d683d826dccd | 402 | |
hudakz | 13:b593a82ce790 | 403 | // Convert to floating point value |
hudakz | 13:b593a82ce790 | 404 | temp = toFloat(*p_word); |
hudakz | 24:d683d826dccd | 405 | return 0; // return with no errors |
hudakz | 13:b593a82ce790 | 406 | } |
hudakz | 13:b593a82ce790 | 407 | else { |
hudakz | 24:d683d826dccd | 408 | uint8_t cfg = (_data[4] & 0x60); // default 12bit resolution, max conversion time = 750ms |
hudakz | 13:b593a82ce790 | 409 | |
hudakz | 13:b593a82ce790 | 410 | // at lower resolution, the low bits are undefined, so let's clear them |
hudakz | 24:d683d826dccd | 411 | if (cfg == 0x00) |
hudakz | 24:d683d826dccd | 412 | *p_word = *p_word &~7; // 9bit resolution, max conversion time = 93.75ms |
hudakz | 13:b593a82ce790 | 413 | else |
hudakz | 24:d683d826dccd | 414 | if (cfg == 0x20) |
hudakz | 24:d683d826dccd | 415 | *p_word = *p_word &~3; // 10bit resolution, max conversion time = 187.5ms |
hudakz | 13:b593a82ce790 | 416 | else |
hudakz | 24:d683d826dccd | 417 | if (cfg == 0x40) |
hudakz | 24:d683d826dccd | 418 | *p_word = *p_word &~1; // 11bit resolution, max conversion time = 375ms |
hudakz | 13:b593a82ce790 | 419 | |
hudakz | 13:b593a82ce790 | 420 | // Convert the raw bytes to a 16bit signed fixed point value : |
hudakz | 14:b02fa18b294a | 421 | // 1 sign bit, 7 integer bits, 8 fractional bits (two's complement |
hudakz | 13:b593a82ce790 | 422 | // and the LSB of the 16bit binary number represents 1/256th of a unit). |
hudakz | 13:b593a82ce790 | 423 | *p_word = *p_word << 4; |
hudakz | 24:d683d826dccd | 424 | |
hudakz | 13:b593a82ce790 | 425 | // Convert to floating point value |
hudakz | 13:b593a82ce790 | 426 | temp = toFloat(*p_word); |
hudakz | 24:d683d826dccd | 427 | return 0; // return with no errors |
hudakz | 13:b593a82ce790 | 428 | } |
hudakz | 13:b593a82ce790 | 429 | } |
hudakz | 13:b593a82ce790 | 430 | else |
hudakz | 24:d683d826dccd | 431 | return 1; // error, sensor is not present |
hudakz | 13:b593a82ce790 | 432 | } |
hudakz | 13:b593a82ce790 | 433 | |
hudakz | 13:b593a82ce790 | 434 | /** |
hudakz | 6:518950e436be | 435 | * @brief Converts a 16-bit signed fixed point value to floating point value |
hudakz | 6:518950e436be | 436 | * @note The 16-bit unsigned integer represnts actually |
hudakz | 6:518950e436be | 437 | * a 16-bit signed fixed point value: |
hudakz | 14:b02fa18b294a | 438 | * 1 sign bit, 7 integer bits, 8 fractional bits (two’s complement |
hudakz | 24:d683d826dccd | 439 | * and the LSB of the 16-bit binary number represents 1/256th of a unit). |
hudakz | 6:518950e436be | 440 | * @param 16-bit unsigned integer |
hudakz | 4:adf4e7972d73 | 441 | * @retval Floating point value |
hudakz | 0:433af64321d5 | 442 | */ |
hudakz | 24:d683d826dccd | 443 | float DS1820::toFloat(uint16_t word) |
hudakz | 24:d683d826dccd | 444 | { |
hudakz | 24:d683d826dccd | 445 | if (word & 0x8000) |
hudakz | 24:d683d826dccd | 446 | return(-float(uint16_t(~word + 1)) / 256.0f); |
hudakz | 0:433af64321d5 | 447 | else |
hudakz | 24:d683d826dccd | 448 | return(float(word) / 256.0f); |
hudakz | 0:433af64321d5 | 449 | } |