This sensor is obsolete now and has been replaced by newer ones but if you still have them lying about then this is how to connect them up to an ESP32
The BMP085 is a high-precision, ultra-low power barometric pressure sensor for use in advanced mobile applications. With a range of 300 hPa to 1100 hPa, an absolute accuracy of 2.5 hPa, and a noise level of down to 0.03 hPa (which is equivalent to an altitude change of merely 0.25 m) the BMP085 offers superior performance.
Schematics/Layout
esp32 and bmp085
Code
Install the Adafruit BMP085 library via the Arduino IDE
[cpp]
#include
#include
/***************************************************
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”);
Serial.print(“Pressure at sealevel (calculated) = “);
Serial.print(bmp.readSealevelPressure());
Serial.println(” Pa”);
Serial.println();
delay(500);
}
[/cpp}
Output
Open the serial monitor and you should see something like this
Temperature = 24.00 *C
Pressure = 101779 Pa
Altitude = -37.32 meters
Pressure at sealevel (calculated) = 101776 Pa
Temperature = 25.00 *C
Pressure = 101772 Pa
Altitude = -37.32 meters
Pressure at sealevel (calculated) = 101774 Pa
