{{tag>dev arduino capteur temperature}}


===== Capteur de température DS18b20 ======

Utilisation du module keyestudio Ks0316 embarquant le circuit DS18b20.
Fonctionne sur la plage -55°C à 125°C, dans la plage -10°C-85°C précision de +-0,5°C 
Résolution adaptable: 9-12 bits

===== Montage =====

===== Code =====

Le code utilise la bibliothèque OneWire disponible a l'adresse http://www.pjrc.com/teensy/arduino_libraries/OneWire.zip

Voir le wiki [[dev:arduino:ide-arduino:gestion-des-bibliotheques]] pour installer la bibliothèque.

<code>
#include <OneWire.h>

 int DS18S20_Pin = 2; //DS18S20 Signal pin on digital pin 2
 //Temperature chip i/o
OneWire ds(DS18S20_Pin);  // on digital pin 2
 void setup(void) {
  Serial.begin(9600);
}
 void loop(void) {
  float temperature = getTemp();
  Serial.println(temperature);  
  delay(100); //to slow down the output so it is easier to read   
} 
float getTemp(){
  //returns the temperature from one DS18S20 in DEG Celsius 
  byte data[12];
  byte addr[8];
  if ( !ds.search(addr)) {
      //no more sensors on chain, reset search
      ds.reset_search();
      return -1000;
  } 
  if ( OneWire::crc8( addr, 7) != addr[7]) {
      Serial.println("CRC is not valid!");
      return -1000;
  }
  if ( addr[0] != 0x10 && addr[0] != 0x28) {
      Serial.print("Device is not recognized");
      return -1000;
  }
  ds.reset();
  ds.select(addr);
  ds.write(0x44,1); // start conversion, with parasite power on at the end
  byte present = ds.reset();
  ds.select(addr);    
  ds.write(0xBE); // Read Scratchpad   
  for (int i = 0; i < 9; i++) { // we need 9 bytes
    data[i] = ds.read();
  }
  ds.reset_search();   
  byte MSB = data[1];
  byte LSB = data[0];
  float tempRead = ((MSB << 8) | LSB); //using two's compliment
  float TemperatureSum = tempRead / 16;
  return TemperatureSum;  
}
</code>

===== Références =====

  * https://wiki.keyestudio.com/Ks0316_Keyestudio_DS18b20_Temperature_Detector_Sensor_(Black_and_Eco-friendly)