Hey, that’s a great idea. I’ve actually built a couple of low‑cost systems that can help in rescue and care. For lost pets I put a small GPS‑module on a custom collar and paired it with a LoRa transmitter so the signal can travel a few miles even in rough terrain. The data feed goes straight into a web dashboard that shows the animal’s location, speed and a battery‑health warning – nothing fancy, just a Raspberry Pi on a drone that can hover over the search area and send a quick video back if the collar’s signal stops. I also made a heart‑rate and temperature sensor module that plugs into a small Arduino and sends alerts when the animal is stressed or too hot. The key is keeping the electronics lightweight, the battery life decent and the software open‑source so shelters can tweak it. If you want to dive in, I can point you toward the code and parts list.

Here’s the link to the repo where I keep all the sketches, firmware and the Python dashboard: https://github.com/tech4pets/rescue‑collar The parts list (I keep it short so you can get a quick quote): - 4 × DFRobot GPS V2 modules - 2 × LoRa SX1278 breakout boards - 1 × Arduino Nano Every (or equivalent low‑power MCU) - 2 × Li‑Po 1000 mAh batteries with built‑in charger - 1 × DFRobot heart‑rate sensor (MAX30102) - 1 × DS18B20 temperature sensor - 4 × PCA9535 I²C GPIO expanders (to keep the I²C bus tidy) - 1 × Raspberry Pi 4 (used only on the drone for the video link) - 1 × Mini‑MAVLink telemetry radio - Basic 3‑axis IMU (MPU‑6050) for attitude filtering - Enclosure: 3D‑printed ABS case with mounting tabs If you’re ready to prototype, just clone the repo, grab the parts and follow the README. I’ve kept the code modular so you can swap in a different MCU or battery pack if you need to. Let me know if you hit any snags or if a shelter has specific requirements – I love tweaking things to fit real‑world use.

Nice, glad the README hit the mark. If you’re aiming for a longer runtime, I’d swap the Nano Every for a STM32‑L0 or an ESP32‑S2 in deep‑sleep mode; those have sub‑µA idle currents. You can also reduce the GPS update rate to 1 Hz or less and keep the LoRa in a low‑power sleep state between packets. That can push a 1000 mAh pack into 10‑12 days if you’re only sampling once a minute. For waterproofing, I recommend a silicone gasket around the 3D‑printed case and a small O‑ring on the lid. Use a hot‑glued cable gland for the sensor leads and seal the mount holes with a small epoxy. If you need a ready‑made solution, I’ve got a version on the repo with a 5 cm thick ABS shell and a waterproofing spray that holds up to IP65; just copy the STL files and the assembly notes. Happy hacking, and ping me if the firmware starts throwing errors or if the shelters want a custom badge.

That’s the spirit! Just keep the firmware tidy and test the sleep cycles early, and you’ll have a rugged, long‑lasting tracker ready for the field. Happy building, and I’m here if anything gets fuzzy.