ENV (DHT12+BMP280)



  • ENV (DHT12+BMP280)
    How can I only address the BMP280?
    The values displayed to me now are very bad,
    in the humidity range they are partly more than 10 % beside it?
    Is there a Python code somewhere where I can connect a BMP280 directly to the M5Stack or other sensors like the SHT 20/21 or 30/31



  • In my ENV Hat, the i2C address for the BMP280 is 0x76. So you can address it there. I found for the ENV hat (for the M5StickC) the temperature is too high because the device itself is hotter than the room. I believe that also affects the humidity. The humidity sensor is very sensitive, so it's hard to tell. Breathing on it will raise the reading by alot (rightly so). The accuracy of the pressure sensor is supposed to be 12 Pa, but I found it to be more like 275 Pa off. When I tested the sensor without being attached to the M5StickC, I found the temperature to be accurate. The BMP also has a temperature sensor on it, which when deattached from the device is also accurate. All these findings were done on the Arduino IDE, not Micropython.



  • I found that, in sources
    https://github.com/m5stack/M5Stack_MicroPython/blob/master/MicroPython_BUILD/components/micropython/esp32/modules/m5flow/units.py

    There is ENV sensor object. But it does not work, because there is no dht12 and bmp280 modules.
    I am not sure if developers test their devices on micropython.
    May be, it will be better to use base micropython and add m5 drivers?

    This library worked for me
    https://github.com/dafvid/micropython-bmp280

    addr=0x76