barnum/README_ETH.md

RP2040-ETH WS2812 Network Control

This implementation adds ethernet connectivity to the WS2812 LED control, allowing you to control the LED color over the network.

Hardware Setup

• Board: Waveshare RP2040-ETH
• LED: WS2812 connected to GPIO 25
• Ethernet: CH9120 chip handles TCP/IP communication

Network Configuration

Default settings (can be modified in ch9120.c):

• IP Address: 192.168.1.200
• Port: 1000
• Mode: TCP Client
• Target IP: 192.168.1.10
• Target Port: 2000

Building

cd build
cmake ..
make barnum_eth

Flashing

1. Hold BOOTSEL button and connect USB
2. Copy barnum_eth.uf2 to the RPI-RP2 drive
3. The board will reboot automatically

Usage

Supported Commands

Send these commands as TCP messages to control the LED:

• RED - Set LED to red
• GREEN - Set LED to green
• BLUE - Set LED to blue
• WHITE - Set LED to white
• OFF - Turn LED off
• RGB:r,g,b - Set custom color (e.g., RGB:255,128,0 for orange)

Python Test Client

Use the included test_client.py to test:

# Run demo sequence
python3 test_client.py

# Send single command
python3 test_client.py "RGB:255,0,255"

Features

• Smooth color transitions between commands
• Network status feedback via USB serial
• Acknowledgment messages for each command

Pin Assignments

• WS2812 Data: GPIO 25
• UART TX (CH9120): GPIO 20
• UART RX (CH9120): GPIO 21
• CFG (CH9120): GPIO 18
• RES (CH9120): GPIO 19

Troubleshooting

1. No network connection:

   • Check ethernet cable is connected
   • Verify IP settings match your network
   • Use serial monitor to see debug output

2. LED not responding:

   • Verify WS2812 is connected to GPIO 25
   • Check power supply to LED
   • Monitor serial output for errors

3. Can't flash the board:

   • Make sure to use the correct board setting in CMakeLists.txt
   • The board type is already set to waveshare_rp2040_eth