Cat GPS Tracker & Home Alarm
Keep my cat safe and close to home using Wi-Fi-based tracking, smart alerts, SD card backup, and live map tracking
Author: Dragoș-Andrei Sava
GitHub Project Link: https://github.com/UPB-PMRust-Students/proiect-savaandrei2003
Description
A two-device system based on Raspberry Pi Pico 2W boards to track a cat using GPS and Wi-Fi, while offering local and remote alerts, SD logging, and live map integration via a mobile device.
Key functionalities:
-
The collar Pico W:
- Sends GPS coordinates every 5 seconds via Wi-Fi to:
- The home Pico W
- A server running on my computer
- Saves coordinates on a microSD card if Wi-Fi is unavailable.
- Activates a night mode - LED + beep every 10s - based on light sensor.
- Can activate its buzzer or LED remotely via buttons on the home unit.
- Sends GPS coordinates every 5 seconds via Wi-Fi to:
-
The home Pico W:
- Displays live coordinates or last known data on an LCD screen.
- Triggers LED and buzzer alarm if connection is lost.
- Two buttons control the collar LED or buzzer remotely.
-
The server running on my computer:
- Receives GPS coordinates via HTTP API.
- Maps the real-time location using Leaflet.js + OpenStreetMap.
- Can be accessed via browser for live tracking.
Motivation
Commercial GPS trackers are expensive and full of subscriptions. This DIY alternative uses affordable hardware, local Wi-Fi, and a custom pc-hosted map server to help my mother keep track of her cat. It offers a rich feature set including real-time alerts, offline GPS logging, and a live web map.
Architecture
Log
Week 5 - 11 May
Week 12 - 18 May
Week 19 - 25 May
Hardware
- Raspberry Pi Pico 2W x2:
- Wi-Fi-enabled microcontrollers
- One on the cat's collar, one in the house
- GY-NEO6MV2:
- GPS module
- Real-time positioning of the cat
- TSL2561:
- Light intensity sensor
- Takes periodic measurements and sends the data to the MCU
- Detects ambient darkness to trigger beacon mode
- LCD screen:
- Shows live GPS coordinates in house
- LEDs x2:
- One on the collar for visibility in dark
- One in house unit for alarm signal
- Buzzer x2:
- One in collar for locating the cat
- One in house unit for lost-signal alarm
- Push Buttons ×2
- Control collar LED and buzzer remotely
- SD Card Module + microSD
- Stores GPS coordinates when offline
Schematics
Bill of Materials
| Device | Usage | Price |
|---|---|---|
| Raspberry Pi Pico 2W | The microcontroller and debugger | 39.66 RON × 2 |
| TSL2561 | Light intensity sensor | 22.99 RON |
| GY-NEO6MV2 | GPS Module | 44.95 RON |
| SD Card Module | Write data locally | 7,14 RON |
| Breadboard | Connect all the components | 9.98 RON x2 |
| LCD screen | Display the sensors' measurements | 16.34 RON |
| Buzzer | Audio alarm | 1.40 RON x2 |
| Push Buttons | Remote commands | 0,49 RON x2 |
| LED | Visual alarm | 0.39 RON × 2 |
| Pin header | Connect components to the breadboard | 0.99 RON × 10 |
| Battery holder | Power the circuit | 3.95 RON |
| Total | - | 209,11 RON |
Software
| Library | Description | Usage |
|---|---|---|
| embassy-rp | RP2040 HAL | GPIO, UART, SPI, I2C |
| embassy-time | Timekeeping, delays and timeouts | Create timers |
| embassy-net | Async network stack | Send messages over Wi-Fi |
| embassy-executor | An async/await executor | Create different tasks |
| lcd1602-rs | Display library | Display coordinates |
| heapless | Statically allocated data | Buffers for display and packets |
| embedded-sdmmc | Filesystem access to SD card | Log coordinates when offline |