FreeRTOS rendering pipeline
Compressed WebP animations are downloaded over HTTP, decoded into composited RGBA frames with libwebp, and streamed into a DMA-backed framebuffer.
P—002 / Connected hardware
Minitron
01 / Overview
Minitron is an ESP32-powered 64x32 HUB75 LED information panel with a FreeRTOS animation pipeline and a Dockerized FastAPI backend aggregating live weather, NYC subway, Spotify, and Formula 1 data.
- Contributors
- Sanjay Kumar
- Project dates
- May 2025 - August 2025
02 / Tools & technologies
11 tools- C++
- C
- FastAPI
- Docker
- ESP32
- FreeRTOS
- I2S DMA
- HUB75
- libwebp
- Arduino
- PlatformIO
03 / Technical highlights
Design / ImplementationSafe live content updates
Mutex-protected, PSRAM-aware buffer management coordinates network and rendering workloads. Versioned shared state allows display content to be replaced without invalidating active animation buffers.
Continuous display refresh
I2S DMA keeps the timing-sensitive HUB75 display scan running independently of Wi-Fi communication and image decoding.
Live data API
A FastAPI backend aggregates OpenWeatherMap, NYC MTA, Spotify, and Formula 1 services and runs as a Dockerized service on self-hosted infrastructure.
04 / In practice
The 64x32 HUB75 LED matrix is driven by an ESP32 using continuous I2S DMA refresh. Display scanning runs independently of Wi-Fi communication and image decoding, while the firmware downloads WebP animations over HTTP from the remote API.
Panel can display the time with dynamic animations.
Track planes flying overhead