Lightweight, reusable, and portable code to interface the Bosch Sensortec BME280 sensor with STM32F4 microcontrollers.
1.) ARM keil uVision 5 MDK
2.) STM32F4 microcontroller e.g. STM32F407VGTx(STM32F4Discovery board) used in the sample code
3.) Bosch Sensortec BME280 sensor
4.) Breadboard
5.) Connectors (Male-Female jumper wires)
| N | BME280 | STM32 |
|---|---|---|
| 1 | VIN | 3V |
| 2 | GND | GND |
| 3 | SDA | SDA (Sample code uses PB7) |
| 4 | SCL | SCL (Sample code uses PB6) |
The program is divided into 3 layers of software. These layers are:
1.) Low Layer API
2.) High Level API
3.) Main Application
Low Layer APIs are functions that directly interface with the STM32F4 hardware e.g GPIO drivers, I2C drivers, SysTick drivers etc.
High Layer APIs are functions that access the hardware through Low Layer APIs thereby creating a level of abstraction e.g. BME280 drivers, and System drivers etc
The Main Application is a layer of software that is intended to reflect the logic behind the project without knowing much about the hardware. It i the highest level of abstraction and it calls High Layer APIs in order to perform operations.
The humidity, pressure and temperature readings of the BME280 sensor are contained in a variable of type bme280_t whose address is passed to the BME280_Get_Data() function. For demonstration purposes, the structure variable that contains the sensor data is named bme280Data and declared in the main function as follows:
bme20_t bme280Data;
Steps:
1.) Open Keil uVision debugger and ensure the active window is the main.c
2.) Set a breakpoint on the line in which the System_Timer_DelayMs() function is called in the while(1) loop
3.) Add bme280Data structure to one of the watch windows
3.) Run the debugger
4.) When the debugger stops, check the bme280Data's humidity, pressure and temperature structure members for the BME280 sensor's readings.
1.) STM32F4 reference manual
2.) BME280 Datasheet
3.) STM32F407 datasheet
To use the project in a plug-and-play manner, follow the connections and instructions above and run the sample code on an STM32F4 board.