A small project to demonstrate how to talk to a device on the I2C bus without third party libraries. This uses microPython on the Pi Pico with a BME280 Sensor.
The BME280 is an environmental sensor capable of measuring temperature, pressure and humidity
Attach the sensor to the Pi Pico as shown below
| Pi Pico | Pin | BME280 |
|---|---|---|
| GP0 | 1 | SDA |
| GP1 | 2 | SCL |
| GND | 3 | GND |
| 3V3(OUT) | 4 | 2-6V |
The code is in a style to aid understanding rather than being production ready. For example:
- The calculations are presented as close to the examples in the datasheet as possible
- Constant values are re-read on each run instead of being stored
- No checks for sensor existence or readiness are included
- Lots of output !
i2c devices found at
0x76
Sensor data
0x88: 66 6F B8 69 32 00 B0 92
0x90: BA D6 D0 0B F1 19 DC FF
0x98: F9 FF AC 26 0A D8 BD 10
0xa0: 00 4B 79 00 00 00 00 00
0xa8: 00 00 00 00 33 00 00 C0
0xb0: 00 54 00 00 00 00 60 02
0xb8: 00 01 FF FF 1F 4E 08 00
0xc0: 00 40 6F FF 00 00 00 00
0xc8: 03 00 00 00 00 00 00 00
0xd0: 60 00 00 00 00 00 00 00
0xd8: 00 00 00 00 00 00 00 00
0xe0: 00 74 01 00 12 28 03 1E
0xe8: 00 41 FF FF FF FF FF FF
0xf0: FF 00 03 0C 6F 00 00 55
0xf8: EE 40 82 2F 80 6A E1 80
Temperature is 24.43 degrees
Pressure is 980.704 mbar
Humidity is 47.62598 %
The BME280 sensor used
Bosch datasheet for the sensor
If you find this project useful, you may want to Buy me a Coffee! ☕ Thanks 👍