AWTRIX NG: build a smart LED pixel clock from an ESP32 and a WS2812B matrix

AWTRIX NG is open firmware for LED pixel clocks, and its docs walk you through building one yourself. The build needs only two things: an ESP32 or ESP32-S3 board and a WS2812-style LED panel 8 pixels high and 32 to 128 pixels wide, plus a 5 V supply (3 to 4 A for a 32 x 8 panel). A 1000 µF capacitor across the panel's power input and a 330 to 470 ohm resistor in the data line keep it reliable, and a milky diffuser makes the pixels readable as text. Buttons, a light sensor, a temperature sensor, a buzzer and a battery are optional. Wire it to the standard pinout and there are no pins to set; other pins can be set in the web UI. Installation happens in the browser. Once it runs, the clock shows the time, the date and its sensor readings, plus whatever your smart home sends it over HTTP or MQTT: the washing machine is done, someone is at the door, the train is late. Home Assistant finds it through MQTT discovery, and apps you write run on the clock itself, so it keeps working without a server. An ESP32-S3 with PSRAM and an I2S amplifier adds MP3s and internet radio. Rather not build one? The same firmware runs on the ready-made Ulanzi TC001 and TC002 clocks.