Payload PCB - UBC Rocket

A self-contained flight-experiment and data-logging payload. An STM32G0B1 host MCU runs the experiment (UV LED actuation, pump), logs motion and temperature data to microSD, and downlinks over LoRa, with a buzzer and status LED for recovery.

• MCU: STM32G0B1CBT - Arm Cortex M0+, 64 Mhz

• Motion: IMU (accelerometer + gyroscope) on shared SPI (SPI2), dedicated CS and interrupt lines per sensor

• Storage: microSD over SPI (SPI1) with card-detect

• Comms: LoRa radio over UART for telemetry; debug UART for bring-up

• Expansion: three independent I²C buses (I²C1/2/3), each broken out to a connector with local pull-ups

• UV LED driver: constant-current buck (VBAT input, 10 µH / 3.2 A inductor, 60 V 2 A Schottky), 0.5 A set by a 400 mΩ sense R, PWM-dimmable 5–100 kHz for 1–100% brightness; up to three LED outputs

• Sensing: temperature sensor; battery sense (VBAT trigger + sense divider)

• Actuation/UI: pump control, buzzer, status LED