Version 0.96 of the Pixie board includes the following:
- 24x24 mm board, with 20 mm hole spacing
- 2 grams
- STM32F415RG MCU
- MPU-9250 IMU (via SPI)
- MS5611-01BA03 Pressure Sensor (via SPI)
- MX25L3206E 32 Mb SPI Flash
- USB OTG
- 10-pin servo port, supporting 8 output(/input) channels
- USART1 port
- USART3/I2C port
- USART2 port with flow control. Also supports 4 ADC. Can also serve as a combination Voltage / Current / Sonar / Rx input port.
- CAN port with 3.3V transceiver
- 12 pin (dual 0.05") expansion header, supporting SPI2, UART6, and SWD. Also contains CAN2 (without transceiver).
- Expansion header outputs both battery/USB voltage and 3.3V (up to 500mA total current).
So far I've been able to load a version of a TauLabs bootloader and firmware and verify that the MPU-9250 and SPI flash work as expected. Unfortunately the board has a minor defect that destroyed the chip select line on the pressure sensor, so I'm currently unable to test that. I still need to test the CAN interface and all the I/O ports.
For some reason the magnetometer is flaky on the MPU-9250. Sometimes it is detected and sometimes not. I suspect the MPU-9250 is just bad, but I need to replace it to know for sure. It's been re-flowed a couple of times, so it might be just heat damaged.
As soon as I have the firmware fully configured I plan to flight test it. I have a couple of options for mounting it, as I'll go over in a future post.