Atmospheric pressure sensors
Samovar 7.00: the sensor type is selected on the "Sensors" («Датчики») tab of the configurator; editing Samovar_ini.h by hand is only needed for a non-standard build.
Note.
Samovar works without this sensor, but it is better to install it, especially since the sensor costs very little.
The project can use BMP180, BMP280, BME280 and BME680 sensors. Some of these sensors can measure not only atmospheric pressure and temperature, but also humidity and even air quality.
Samovar uses only the atmospheric pressure data, so it makes no difference which of these sensors you use.
The sensor is connected to the I2C bus together with the display: SDA D21 and SCL D22 on ESP32 DevKit, GPIO33/GPIO32 on LILYGO T-Relay 4, GPIO8/GPIO9 on ESP32-S3. The readings are converted to mm Hg and used to correct the boiling temperature.
The printed circuit board has pads for a 6-pin sensor, of which only 4 pins are connected.
So if you are buying a sensor rather than using one you already have, it is better to take the simple and reliable BMP180. You can read more about this sensor
in this review.
The sensor needs no additional setup.
Warning
Because the sensors work over the I2C bus, some BMP280 sensors may have a different address. In that case, uncomment the line #define USE_BMP280_ALT in the Samovar_ini.h file
That is, it should look like this:
...
//#define USE_BMP280 //use the BMP280 pressure sensor
#define USE_BMP280_ALT //use the BMP280 pressure sensor with the alternative address.
The standard Samovar 7.00 configuration has the BME680 enabled. In the configurator, the sensor is selected on the "Sensors" («Датчики») tab in the "Atmospheric pressure" («Атмосферное давление») field: "BMP180/BMP085", "BMP280", "BMP280, alternative address" («BMP280, альтернативный адрес»), "BME280", "BME680" or "Do not use" («Не использовать»). When building in the Arduino IDE, leave exactly one matching directive active in Samovar_ini.h; for a BMP280 with the alternative address, use USE_BMP280_ALT.
It is best to solder the sensor board directly onto the printed circuit board.
