Software for avionics package based on WEMOS LOLIN32 board.
LOLIN32 is a board based on ESP32 WROOM module.
This software has been developed with couple of peripheral modules connected to LOLIN32:
- uSD card,
- BMP280 (pressure altimeter),
- MPU9250 (inertial measurement unit consisting of AK8963 magnetometer and MPU6500 accelerometer+gyro),
- Buzzer (optional).
In the example design, GY-91 sensor board has been used. It holds BMP280 and MPU9250.
The example design uses the following mapping (most of it is unnecessary for basic functionality):
| ESP32 pin | Peripheral pin | Notes |
|---|---|---|
| GPIO32 | SD card MISO | |
| GPIO33 | SD card MOSI | |
| GPIO26 | SD card CS | |
| GPIO12 | SD card SCK | |
| GPIO17 | IMU+baro SCL | |
| GPIO16 | IMU+baro SDA | |
| GPIO4 | IMU+baro SDO | unused in I2C mode, leave in hi-Z pull-down mode |
| GPIO5 | LED0 - | blue LED on WEMOS LOLIN32, anode connected to VCC through 2k resistor |
| GPIO22 | LED1 + | low power green LED |
| GPIO21 | LED1 - | connected through resistor to GND - leave in hi-Z mode |
| GPIOxx | LED2 - | bright blue LED, anode connected to VCC without resistor |
| GPIO13 | Buzzer + | use with low duty cycle |
Running sensors in SPI mode is possible, but would require wiring 2 more pins: CSB and nCS.
I2C slave addresses of the peripherals are as follows:
- MPU9250 - 0x68
- BMP280 - 0x76