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 } } }
Diff: DS1820.cpp
- Revision:
- 8:8dfdd1603e4d
- Parent:
- 6:518950e436be
- Child:
- 11:9be3e73c01f1
diff -r 4403a206e78a -r 8dfdd1603e4d DS1820.cpp --- a/DS1820.cpp Thu Mar 26 20:57:59 2015 +0000 +++ b/DS1820.cpp Fri Mar 27 12:34:16 2015 +0000 @@ -46,8 +46,8 @@ */ DS1820::DS1820(PinName pin) : oneWire(pin) { - present = 0; - type_s = 0; + present = false; + model_s = false; } /** @@ -60,15 +60,15 @@ DS1820::DS1820(char model, PinName pin) : oneWire(pin) { if((model == 'S') or (model == 's')) { - present = 1; - type_s = 1; + present = true; + model_s = true; } else if((model == 'B') or (model == 'b')) { - present = 1; - type_s = 0; + present = true; + model_s = false; } else - present = 0; + present = false; } /** @@ -99,33 +99,33 @@ #endif if(OneWire::crc8(addr, 7) == addr[7]) { - present = 1; + present = true; // the first ROM byte indicates which chip switch(addr[0]) { case 0x10: - type_s = 1; + model_s = true; #if DEBUG serial.printf("DS18S20 or old DS1820\r\n"); #endif break; case 0x28: - type_s = 0; + model_s = false; #if DEBUG serial.printf("DS18B20\r\n"); #endif break; case 0x22: - type_s = 0; + model_s = false; #if DEBUG serial.printf("DS1822\r\n"); #endif break; default: - present = 0; + present = false; #if DEBUG serial.printf("Device doesn't belong to the DS1820 family\r\n"); #endif @@ -142,6 +142,19 @@ } /** + * @brief Informs about presence of a DS1820 sensor. + * @note begin() shall be called before using this function + * if a generic DS1820 instance was created by the user. + * No need to call begin() for a specific DS1820 instance. + * @param + * @retval true: when a DS1820 sensor is present + * false: otherwise + */ +bool DS1820::isPresent(void) { + return present; +} + +/** * @brief Sets temperature-to-digital conversion resolution. * @note The configuration register allows the user to set the resolution * of the temperature-to-digital conversion to 9, 10, 11, or 12 bits. @@ -156,7 +169,7 @@ res = 12; if(res < 9) res = 9; - if(type_s) + if(model_s) res = 9; oneWire.reset(); @@ -173,7 +186,6 @@ oneWire.write(data[i]); } - /** * @brief Starts temperature conversion * @note The time to complete the converion depends on the selected resolution: @@ -213,7 +225,7 @@ serial.printf("raw = %#x\r\n", *p_word); #endif - if(type_s) { + if(model_s) { *p_word = *p_word << 3; // 9-bit resolution if(data[7] == 0x10) { @@ -264,3 +276,4 @@ return (float(word) / 256.0f); } +