A nRF24L01-based firmware to handle data collection, transmission, and basic self-diagnostics.
Communicates with a series of other nodes and one nrf_bridge in a star configuration. Node collects and transmits data from the field. Bridge acts as a relay between remote nodes and an IP-enabled processing device. Based on a STM32030F4 microcontroller.
MCU pin assignment and basic configuration
Battery management circuit and component selection; mic frontend
Buck/Boost regulator (RT6150) inductor selection
First revision boards had reversed the Wheatstone bridge's connection to the amplifier (A-5 on the schematic), rendering the light sensing interface inoperable. Subsequent troubleshooting and board hacking with a razor and winding wire fixed the issue. The circuit and PCB layout were corrected in a subsequent revision.