Le capteur de pression barométrique et de température BMP085:
(Barometric Pressure + Temp sensor):
Caractéristiques :
• Interface numérique à 2 fils (I2C)
• Large échelle de pression barométrique (échelle de mesure de 300 à 1 100 hPa)
• Gamme de tension d'alimentation flexible (entre 1,8 et 3,6 Vcc)
• Consommation d'énergie ultra-faible
• Mesure de bruits faibles
• Totalement calibré
• Mesure de la température comprise
• Ultra-plat, faible encombrement
Vendeurs chinois sur Ebay 5 à 20€ : tx-hang
testé avec l'alimentation en 3.3v et 5v, ça fonctionne bien.
Exemple d'utilisation avec la librairie Adafruit
#include <Wire.h>
#include <Adafruit_BMP085.h>
/***************************************************
This is an example for the BMP085 Barometric Pressure & Temp Sensor
Designed specifically to work with the Adafruit BMP085 Breakout
----> https://www.adafruit.com/products/391
These displays use I2C to communicate, 2 pins are required to
interface
Adafruit invests time and resources providing this open source code,
please support Adafruit and open-source hardware by purchasing
products from Adafruit!
Written by Limor Fried/Ladyada for Adafruit Industries.
BSD license, all text above must be included in any redistribution
****************************************************/
// Connect VCC of the BMP085 sensor to 3.3V (NOT 5.0V!)
// Connect GND to Ground
// Connect SCL to i2c clock - on '168/'328 Arduino Uno/Duemilanove/etc thats Analog 5
// Connect SDA to i2c data - on '168/'328 Arduino Uno/Duemilanove/etc thats Analog 4
// EOC is not used, it signifies an end of conversion
// XCLR is a reset pin, also not used here
Adafruit_BMP085 bmp;
void setup() {
Serial.begin(9600);
if (!bmp.begin()) {
Serial.println("Could not find a valid BMP085 sensor, check wiring!");
while (1) {}
}
}
void loop() {
Serial.print("Temperature = ");
Serial.print(bmp.readTemperature());
Serial.println(" *C");
Serial.print("Pressure = ");
Serial.print(bmp.readPressure());
Serial.println(" Pa");
// Calculate altitude assuming 'standard' barometric
// pressure of 1013.25 millibar = 101325 Pascal
Serial.print("Altitude = ");
Serial.print(bmp.readAltitude());
Serial.println(" meters");
// you can get a more precise measurement of altitude
// if you know the current sea level pressure which will
// vary with weather and such. If it is 1015 millibars
// that is equal to 101500 Pascals.
Serial.print("Real altitude = ");
Serial.print(bmp.readAltitude(101500));
Serial.println(" meters");
Serial.println();
delay(500);
}
résultat obtenu :
Temperature = 30.76 *C
Pressure = 98245 Pa
Altitude = 259.56 meters
Real altitude = 274.03 meters