Modifications

However, by default, the Arduino's {{fname|analogRead()}} use a 10 bit coding. So the range of possible value return by {{fname|analogRead()}} is 0 to 1024 (for 0 to 3.3v). This means that the accuracy of reading is 3.3 / 1024 = 0.0032 Volts, so 3.2 mV.

However, by default, the Arduino's {{fname|analogRead()}} use a 10 bit coding. So the range of possible value return by {{fname|analogRead()}} is 0 to 1024 (for 0 to 3.3v). This means that the accuracy of reading is 3.3 / 1024 = 0.0032 Volts, so 3.2 mV.

As the M0 does have an Analog-to-digital converter with a precision of 12 bits, we could also use the {{fname|analogReadResolution( 12 )}} to upgrade the {{fname|analogRead()}} resolution to 12 bits. In such case, the range of possible value return by {{fname|analogRead()}} is 0 to 4095 (for 0 to 3.3v). This means that the accuracy of reading is 3.3 / 4095 = 0.000805 Volts, so 0.805 mV.

As the M0 does have an ADC (''Analog-to-Digital Converter'') with a precision of 12 bits, we could also use the {{fname|analogReadResolution( 12 )}} to upgrade the {{fname|analogRead()}} resolution to 12 bits. In such case, the range of possible value return by {{fname|analogRead()}} is 0 to 4095 (for 0 to 3.3v). As we have a real 12bit ADC, we can rely on that accuracy (it is not a 10 bits ADC storing the data into a 12 bits integer).

with 12bits we have an reading accuracy of 3.3 / 4095 = 0.000805 Volts, so 0.805 mV.

   

   

=== Low resolution reading ===

=== Low resolution reading ===

=== High resolution reading ===

=== High resolution reading ===

// where is wired the TMP36

const int temperaturePin = A3; // analogue input

* actuelle dans la fenêtre de monitoring/débogage

*/

 

// Variable pour broche du TMP36

const int temperaturePin = A3; // entrée analogique

void setup() {

void setup() {

   Serial.begin(9600); // Démarrer la connexion série avec l'ordinateur.

      // Pour voir le le résultat, ouvrez le « moniteur série », le

   Serial.begin(9600);  

  // Upgrade the ADC resolution from 10 to 12 bits.

      // (celui qui ressemble à une boite ayant une antenne).

   analogReadResolution( 12 );

   analogReadResolution( 12 );

}

}

void loop() { // s'exécute encore et encore

   // Acquérir la tension lue sur le senseur de température.

void loop() {  

   // read the voltage of TMP36

   float voltage = getVoltage(temperaturePin);  

   float voltage = getVoltage(temperaturePin);  

   Serial.print( "Voltage : " );

   Serial.print( "Voltage : " );

   Serial.print( voltage );

   Serial.print( voltage );

   Serial.println( " Volts" );  

   Serial.println( " Volts" );  

   // conversion de 10mV par degré avec un décalage (offset) de 500 mV.

   // convert voltage to temperature

   //  Degrés = ((tension - 500mV) fois 100)

   //  Degrees = (voltage - 500mV) multiplied by 100

   float temperature = (voltage - .5) *100;

   float temperature = (voltage - .5) *100;

   Serial.print( "Temperature: " );

   Serial.print( "Temperature: " );

   Serial.print(temperature); //affiche résultat

   Serial.print(temperature);  

   Serial.println( " °C" );

   Serial.println( " °C" );

   Serial.println( " " );

   Serial.println( " " );

   delay(1000); // Attendre une seconde.

   delay(1000); // wait 1 second

}

}

/*

/*

  * getVoltage() - retourne la tension d'une entrée analogique identifiée par 'pin'

  * getVoltage() - return the voltage of an analog pin  

  */

  */

float getVoltage(int pin){

float getVoltage(int pin){

   // Convertir valeur digital de 0 à 4095 vers une valeur entre 0 et 3.3 volts.

   // Convert digital value between 0 & 4095 to

   // (chaque unité lue vaut ~ 3.3 / 4095 = 0.805 millivolts

  //    voltage between 0 & 3.3 volts.

  Serial.println( analogRead(pin) );

   //   (each unit equal 3.3 / 4095 = 0.805 millivolts)

   return (analogRead(pin) * .000805);

   return (analogRead(pin) * .000805);

}

}

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