Solar-Powered GPS Smart Padlock Design

I’m developing a next-generation padlock that couples robust physical security with modern electronics. The core idea is a tamper-resistant body housing a low-power PCB that supports BLE unlocking, RFID credential reading and an always-on GPS module. A compact solar panel must keep the cell topped up so the lock can sit in the field for long stretches without manual charging.

Here is the outline I need your help bringing to life:

• Electronics: choose components, lay out the PCB and write the embedded code so the lock wakes only when needed, yet still logs location pings. Expect Nordic-style BLE, an ultra-low-power GPS, RFID reader IC, power-path management and secure element for key storage.
• Power strategy: harvest energy from the solar cell, switch gracefully to an internal Li-ion/Li-poly pack at night, and hit an ultra-low sleep current budget.
• Security & anti-tamper: harden the firmware, design intrusion switches and defeat-detection circuitry so any attempt to pry the enclosure or shield the panel is reported.
• Mechanical integration: advise on housing dimensions and antenna placement so metal parts don’t cripple RF performance.
• Prototype and test: once schematics and Gerbers are complete, iterate until we have a field-ready sample that meets the above goals.

We can discuss exact specs such as operating cycles, GPS update rate and BLE advertising intervals, but the headline requirement is clear integration of BLE, RFID, GPS and solar charging in a single, compact padlock that simply can’t be easily tampered with.

If you have a track record in ultra-low-power IoT hardware and secure firmware, I’d like to see how you would tackle this challenge and what timeline you propose.