ESP32 MQTT LED Text Display

I am setting up an ESP32 to drive an LED display and need reliable firmware that shows plain text messages received over MQTT. The messages will arrive in JSON format from my own application or directly through my broker; the code simply has to subscribe, parse the JSON, pull out the text field, and push it to the display. No animations or extra status indicators are required at this stage—just clear, readable text.

Subscribe Topic : iot_display/application_to_display
Publish Topic : iot_display/display_to_application



Preferred tool-chain is Arduino IDE or PlatformIO with a familiar MQTT library such as PubSubClient or AsyncMQTT. Please keep the pin assignments and Wi-Fi credentials easily configurable in a header or defines section, and make sure the loop stays non-blocking so the device can reconnect gracefully if the network drops.

Deliverables
• Complete, well-commented source code and any custom libraries
• A short README covering wiring, topic structure, and build steps
• Proof of function (photo, short video, or serial log) showing a JSON payload received via MQTT and rendered on the LED display

Acceptance Criteria
1. After power-up the ESP32 connects to Wi-Fi and my broker without manual intervention.
2. When a JSON message containing a text field is published, the display updates within two seconds.
3. If the MQTT connection breaks, the device recovers automatically and continues displaying new messages.

That’s the full scope; if you have suggestions for keeping the code lean or improving display clarity, feel free to include them in your bid.