SmartRace ESP32-C6 Light Controller

Control Govee network lights, onboard RGB LED, LCD display, and a relay based on SmartRace slot car racing events. Displays track conditions (weather) and race status through color-coded lighting.

Features

• SmartRace Integration: Receives events via HTTP POST from SmartRace Data Interface
• Govee Light Control: Controls H7020 (and compatible) lights via LAN UDP protocol
• LCD Display: 1.47" ST7789 320x172 with flicker-free partial updates showing race state, weather, relay status, Govee connection, and IP:port
• RGB LED: NeoPixel LED mirrors Govee light colors
• Relay Control: GPIO 23 (open drain) pulses HIGH for 5 seconds on race stop/end events
• Web Interface: Manual testing UI at http://<device-ip>/
• mDNS Support: Access via http://src.local
• Duplicate Event Filtering: Ignores repeated SmartRace events when already in that state

Display Layout

The LCD uses a split layout with flicker-free partial updates (no full-screen redraws):

• Left panel (200px): Large color-coded status indicator with word-wrapped text. IP:port shown at the bottom within the color band.
• Right panel (120px): Race state, weather condition, Govee connection, and relay status. Labels are drawn once at boot; only values are updated.

Light Colors

Condition	Color
Race Running (no weather)	White
Track Dry	White
About to Rain	Purple
Track Wet	Blue
Track Drying	Green
Race Stopped/Ended	Red

Hardware

• Waveshare ESP32-C6 with 1.47" LCD
• Govee H7020 network light (or compatible)
• Relay module on GPIO 23 (open drain, requires external pull-up)

Pin Configuration

Pin	Function
5	LCD MISO
6	LCD MOSI
7	LCD SCLK
8	RGB LED (NeoPixel)
14	LCD CS
15	LCD DC
21	LCD RST
22	LCD Backlight
23	Relay

Configuration

Edit these values at the top of the .ino file:

const char* WIFI_SSID = "your-wifi";
const char* WIFI_PASSWORD = "your-password";
const char* MDNS_HOSTNAME = "src";
const int RELAY_PIN = 23;
String GOVEE_NETWORK_IP = "";  // Leave empty for auto-discovery

SmartRace Setup

Configure SmartRace Data Interface to POST events to:

http://<ESP32_IP>:8080/

or

http://src.local:8080/

Supported Events

Event Type	Values
event.change_status	starting, running, restarting, suspended, ended
events.weather_update	about_to_rain, about_to_dry_up
events.weather_change	wet, dry

External Trigger

To trigger a race stop from another device (e.g. ESP8266):

POST http://<ESP32_IP>:8080/
{"event_type":"event.change_status","event_data":{"new":"suspended"}}

Building & Uploading

Requires Arduino CLI with ESP32 core installed.

# Compile
arduino-cli compile --fqbn esp32:esp32:esp32c6 .

# Upload (port may vary)
arduino-cli upload --fqbn esp32:esp32:esp32c6 --port /dev/cu.usbmodem14101 .

# Monitor serial output
arduino-cli monitor -p /dev/cu.usbmodem14101 -c baudrate=115200

Web Interface

Access the web UI at http://<device-ip>/ or http://src.local/ to:

• Test race status buttons (Starting, Running, Stopped, Ended)
• Test weather condition buttons (Dry, About to Rain, Wet, Drying)
• Turn lights off
• Manually pulse the relay for 5 seconds

Settings page at /settings allows configuring the Govee light IP address.

Behavior

• Race Stopped/Ended: Lights turn red, relay pulses HIGH for 5 seconds then returns to LOW. Weather condition is stored and displays when race resumes.
• Race Starting: Weather condition is cleared for a fresh start.
• Relay: Default LOW (open drain). Pulses HIGH for 5 seconds when race is stopped or ended. Display updates when timer expires.

Dependencies

• WiFi.h
• WebServer.h
• ArduinoJson.h
• Preferences.h
• ESPmDNS.h
• WiFiUdp.h
• SPI.h
• Adafruit_NeoPixel.h