Renesas R5F100FEA Tracker Firmware

I’m finalising a vehicle-tracking PCB that centres on the Renesas RL78/G13 R5F100FEA MCU and I’d like a firmware specialist to take it from bare silicon to a field-ready prototype.

Core objective
• Develop clean, well-documented C code that handles the MCU start-up, peripheral initialisation and the full real-time location tracking loop.
• Integrate a GPS receiver and a cellular modem over UART/SPI, package NMEA data, and push coordinates to our cloud endpoint with minimal latency.
• Drive an on-board SD-card controller so raw logs are mirrored locally in case connectivity drops, using a simple FAT file structure.
• Keep the design power-aware: sleep modes, clock gating and watchdog strategy are essential for battery life.

Helpful context
Hardware is already routed; I can share PDFs of the schematic, layer stack-ups and the Renesas E2 studio project shell. The board uses:
– UART0 for GPS, UART2 for modem
– SPI0 for the SD interface (3.3 V flash footprint reserved if you prefer)
– A few GPIOs for ignition sense, LED status and a buzzer

Deliverables
1. Compilable E2 Studio project (.c/.h, linker script, start-up).
2. Brief read-me covering build steps, fuse settings and in-field firmware update procedure.
3. One-week post-handover support for bug fixes discovered during bench or road testing.

Acceptance criteria
• On bench with my hardware the MCU must acquire a GPS fix and publish a JSON payload to the test server within 10 seconds of power-up.
• SD card must hold identical coordinate/time stamps for every published sample.
• Average sleep current (ignition off) ≤ 150 µA at 12 V input.

If you’re already comfortable with the RL78 toolchain, Renesas peripheral libraries and low-power embedded networking, this should be a focused engagement. Looking forward to hearing how you’d tackle it.