Printed Circuit Board Design and Embedded Programming : PCB design, component selection, assembly and embedded programming for the central control system of the Methane Infrared Absorption Gas Experiment (MIRAGE) onboard BEXUS39

Sammanfattning

This report presents the design, component selection, assembly and embedded programming of the Central Control System of MIRAGE. Developed for the BEXUS39 research balloon program, MIRAGE aims to demonstrate a low-cost, low-complexity solution for measuring atmospheric methane concentrations using an NDIR sensor. To enable detection at high altitudes where ambient pressure drops significantly, the Central Control System must regulate a pressurized chamber maintained at approximately 3 bar. To satisfy the rigid space constraints (100 mm × 80 mm) and isolate sensitive circuitry from switching noise from the 24 V power rail, the design of the Printed Circuit Board (PCB) was split into two separate PCBs. A Main PCB was built around an ESP32-C5-WROOM-1 microcontroller to handle data aggregation and ground communication, while a dedicated Pressure PCB utilizing an Arduino NanoESP32 governs the 24 V pressurization system. Initial software architecture has been implemented in C++ utilizing ESP-IDF to manage autonomous operations, hardware watchdog management, datalogging, and UDP telemetry via the BEXUS E-Link system. While individual hardware subsystems and communication protocols were successfully verified through basic testing, both the hardware and software systems remain in an unfinalized state. Future work will focus on completing core firmware development, PCB layout optimizations, full system testing and environmental testing to ensure the system is ready for the scheduled flight in October 2026.