Zoltan Hudak
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
Homepage
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
}
}
}