Zoltan Hudak / DS1820

Dallas' DS1820 family temperature sensor. For more details see [https://developer.mbed.org/users/hudakz/code/DS1820/wiki/Homepage]

Dependencies:   OneWire

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/]

Last commit 20 Jul 2020 by Zoltan Hudak

Import programBLE_nRF24L01

Bluetooth Low Energy (BLE) beacon with nRF24L01(+). Data is received and displayed by Android device (Android app source code is attached).

Last commit 26 Jan 2016 by Zoltan Hudak

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.h@14:b02fa18b294a, 2019-01-20 (annotated)

Committer:
hudakz
Date:
Sun Jan 20 10:11:31 2019 +0000
Revision:
14:b02fa18b294a
Parent:
13:b593a82ce790
Child:
20:98c261bcb399
Improved One-Wire.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
hudakz 0:433af64321d5 1 #ifndef DS1820_H_
hudakz 0:433af64321d5 2 #define DS1820_H_
hudakz 0:433af64321d5 3
hudakz 0:433af64321d5 4 #include <OneWire.h>
hudakz 0:433af64321d5 5
hudakz 14:b02fa18b294a 6 /**
hudakz 14:b02fa18b294a 7 * Dallas' DS1820 family temperature sensor.
hudakz 14:b02fa18b294a 8 * This library depends on the OneWire library (Dallas' 1-Wire bus protocol implementation)
hudakz 14:b02fa18b294a 9 * available at <http://developer.mbed.org/users/hudakz/code/OneWire/>
hudakz 14:b02fa18b294a 10 *
hudakz 14:b02fa18b294a 11 * Example of use:
hudakz 14:b02fa18b294a 12 *
hudakz 14:b02fa18b294a 13 * @code
hudakz 14:b02fa18b294a 14 * #include "DS1820.h"
hudakz 14:b02fa18b294a 15 *
hudakz 14:b02fa18b294a 16 * Serial serial(USBTX, USBRX);
hudakz 14:b02fa18b294a 17 *
hudakz 14:b02fa18b294a 18 * int main() {
hudakz 14:b02fa18b294a 19 * DS1820 ds1820(PA_9); // substitute PA_9 with actual mbed pin name connected to the DS1820 data pin
hudakz 14:b02fa18b294a 20 *
hudakz 14:b02fa18b294a 21 * if(ds1820.begin()) {
hudakz 14:b02fa18b294a 22 * ds1820.startConversion();
hudakz 14:b02fa18b294a 23 * wait(1.0);
hudakz 14:b02fa18b294a 24 * while(1) {
hudakz 14:b02fa18b294a 25 * serial.printf("temp = %3.1f\r\n", ds1820.read()); // read temperature
hudakz 14:b02fa18b294a 26 * ds1820.startConversion(); // start temperature conversion
hudakz 14:b02fa18b294a 27 * wait(1.0); // let DS1820 complete the temperature conversion
hudakz 14:b02fa18b294a 28 * }
hudakz 14:b02fa18b294a 29 * } else
hudakz 14:b02fa18b294a 30 * serial.printf("No DS1820 sensor found!\r\n");
hudakz 14:b02fa18b294a 31 * }
hudakz 14:b02fa18b294a 32 *
hudakz 14:b02fa18b294a 33 * @endcode
hudakz 14:b02fa18b294a 34 *
hudakz 14:b02fa18b294a 35 * Note: Don't forget to connect a 4.7k Ohm resistor
hudakz 14:b02fa18b294a 36 * between the DS1820's data pin and the +3.3V pin
hudakz 14:b02fa18b294a 37 *
hudakz 14:b02fa18b294a 38 */
hudakz 0:433af64321d5 39 class DS1820
hudakz 0:433af64321d5 40 {
hudakz 0:433af64321d5 41 OneWire oneWire;
hudakz 8:8dfdd1603e4d 42 bool present;
hudakz 8:8dfdd1603e4d 43 bool model_s;
hudakz 0:433af64321d5 44 uint8_t data[12];
hudakz 0:433af64321d5 45 uint8_t addr[8];
hudakz 0:433af64321d5 46 float toFloat(uint16_t word);
hudakz 0:433af64321d5 47 public:
hudakz 7:4403a206e78a 48
hudakz 0:433af64321d5 49 DS1820(PinName pin);
hudakz 0:433af64321d5 50 DS1820(char model, PinName pin);
hudakz 0:433af64321d5 51 bool begin(void);
hudakz 8:8dfdd1603e4d 52 bool isPresent();
hudakz 4:adf4e7972d73 53 void setResolution(uint8_t res);
hudakz 0:433af64321d5 54 void startConversion(void);
hudakz 0:433af64321d5 55 float read(void);
hudakz 13:b593a82ce790 56 uint8_t read(float& temp);
hudakz 0:433af64321d5 57 };
hudakz 0:433af64321d5 58 #endif /* DS1820_H_ */