Description
Developed a FreeRTOS firmware stack for SGP40, VEML7700, BME688 (via TCA6408), and BNO055 with PCF8523 RTC timestamping; executed full sensor-read + JSON logging every 3 s.
Implemented a FATFS microSD SPI logger with robust append/seek, enabling 7+ days of uninterrupted capture on a 5000 mAh pack (~30 mA average draw).