Raspberry Pi Pico + W5500 + GPS TCP API Server
Rust-based embedded project for RP2040, W5500, and Pico-GPS-L76K GPS module to create TCP API server that can respond to HTTP request/provide GPS data in JSON.
0
Components
Hardware components
WIZnet - WIZPoE-P1
x 1
WIZnet - W5500-EVB-Pico-PoE
x 1
Waveshare - L76K GNSS module
x 1
Project description
This is a Rust-based embedded project for the Raspberry Pi Pico (RP2040) that uses:
W5500 Ethernet module for network connectivity
Pico-GPS-L76K GPS module for GPS data
Embassy asynchronous framework and embedded networking
to create a TCP API server on the Pico that can respond to HTTP requests and provide GPS data in JSON.
🧠 Key Features
The device supports:
✅ Ethernet via W5500 (SPI)
✅ Automatic DHCP IP address
✅ ICMP Ping responses
✅ TCP API server on port 8080
✅ JSON formatted responses
✅ GPS module support with NMEA 0183 parsing
✅ Provides GPS location & time over network API
🔌 Hardware Setup
MCU: Raspberry Pi Pico (RP2040)
Ethernet: W5500 connected via SPI
GPS: Pico-GPS-L76K connected via UART (9600 bps)
Detailed pin wiring for both modules is described in the README.
🧩 Network API Endpoints
Here’s how you can interact with the server:
| Endpoint | Method | Returns |
|---|---|---|
/ or /status | GET | { "status":"ok", ... } |
/ping | GET | { "message":"pong" } |
/api/info | GET | List of available endpoints |
/api/gps | GET | GPS data (JSON) |
/api/gps/mode/{...} | GET | Change GPS output mode |
GPS output modes:
log – Only logs data
tcp – Only outputs via TCP
both – Logs + TCP (default)
none – No output
🛰️ GPS Data Example
Example JSON from /api/gps:
{
"gps": {
"valid": true,
"position": {
"latitude": 35.681236,
"longitude": 139.767125
},
"time": {
"utc": "12:34:56",
"date": "2024-01-15"
},
"satellites": 8,
"altitude": 45.5,
"speed_knots": 0.0
}
}
``` :contentReference[oaicite:6]{index=6}
---
### ⚙️ **Tech Stack**
- **Language:** Rust (no_std)
- **Async framework:** Embassy
- **Network stack:** embassy-net (smoltcp based)
- **W5500 driver:** embassy-net-wiznet
- **Logging:** defmt + RTT :contentReference[oaicite:7]{index=7}
---
### 🚀 **Build & Flash Instructions**
Typical steps to compile and run:
1. Add Rust target:
```bash
rustup target add thumbv6m-none-eabi
Install probe tools:
cargo install probe-rs-tools --lockedBuild and flash using cargo commands:
cargo build --release
cargo run --release
``` :contentReference[oaicite:8]{index=8}
🧪 Usage & Testing
You can test the device with:
Ping:
ping <PICO_IP_ADDRESS>HTTP (cURL):
curl http://<IP>:8080/status
curl http://<IP>:8080/api/gps
``` :contentReference[oaicite:9]{index=9}
⚙️ Configuration Options
You can modify MAC address / TCP port / GPS baud rate / Static IP instead of DHCP
via the source code configuration.
🧰 Project Structure
The main components in the source code:
src/
├── main.rs // init & HW setup
├── network.rs // network stack & DHCP
├── tcp_server.rs // API server logic
└── gps.rs // GPS parsing + UART
``` :contentReference[oaicite:11]{index=11}
---
### 📄 **License**
MIT License. :contentReference[oaicite:12]{index=12}
🔑 Key Benefits
1. Deterministic & Stable Networking
The W5500 hardware TCP/IP offload removes the need for a heavy software TCP/IP stack on the MCU.
Results in predictable latency, lower CPU usage, and higher reliability, especially valuable for industrial or long-running deployments.
2. Clean Separation of Concerns
Networking, GPS parsing, and application logic are clearly separated.
Makes the project easy to extend with additional sensors, protocols, or endpoints.
3. Modern Embedded Rust Architecture
Uses Rust + Embassy async, showing how to write:
Non-blocking UART (GPS)
Concurrent network services
Safe, memory-efficient embedded code
Serves as a real-world learning reference for embedded Rust beyond simple demos.
4. Ethernet as a Strong Alternative to Wi-Fi
Ethernet provides:
Better stability
Lower jitter
Easier IT integration (DHCP, fixed ports, predictable behavior)
Ideal for industrial IoT, gateways, lab equipment, and infrastructure devices where Wi-Fi is undesirable.
5. Ready-to-Use Network API
The HTTP/TCP API makes GPS data immediately consumable by:
- Servers / Dashboards / Data loggers / Cloud ingestion pipelines
- Minimal integration effort for system-level developers.
6. Excellent Reference for RP2040 + Ethernet Designs
Shows practical wiring, SPI usage, DHCP handling, and TCP server design.
Can be reused as a template for other Ethernet-based RP2040 projects such as:
- Industrial sensors
- Time-sync devices
- Asset-tracking nodes
- Network-attached controllers
🎯Conclusion
This project demonstrates a clean, modern reference design for building an Ethernet-enabled embedded edge device using Raspberry Pi Pico, W5500, and Rust. By combining hardware-offloaded TCP/IP with an asynchronous software stack, it shows how even a resource-constrained MCU can reliably expose network APIs and real-world sensor data.
