Bring HDTV Capability to Small MCUs with TechToys’ HDMI Shield

Hong Kong-based hardware developers TechToys have designed a shield that provides HDMI support for modern microcontrollers, allowing them to pipe a 1080p signal to HDTVs. While there are some great projects that can provide HD video to MCUs, producing an HDMI signal isn’t as easy as it sounds, as it’s a proprietary interface and specification for transmitting uncompressed audio and video. It’s by no means an open source platform, which means it requires a little trickery to get it to work with small development boards.

The HDMI Shield uses a RA8876 MIPI TFT controller and CH7035B HDMI encoder to produce a resolution of 1920 x 1080 at 60Hz. (📷: TechToys)

That being said, it’s not an impossible endeavor, and the engineers at TechToys have managed to create an Arduino HDMI Shield capable of doing the trick. The board features two different circuits to accomplish this feat, including a RA8876 MIPI TFT controller, which is a graphics engine that generates RGB video in 8:8:8 format. A CH7035B HDMI encoder converts that RGB signal into differential signals needed to produce an HDMI output.

TechToys is also offering some add-on boards to enhance the Arduino HDMI Shield — a Due Zipper Board outfitted with an ESP8266 for wireless applications, a Teensy 3.2/3.5 Stacker Board (the company states this is the best board for audio), and an RA8876/77 AP Board with STM32F103VET6 MCU, which ports video and images over to HDTVs. TechToys says their Shield has been thoroughly tested with ESP32/8266, DUE, Arduino M0, Arduino 101, and Teensy 3.2/3.5-based boards, but I suspect it will work with any board compatible with the Arduino IDE. has uploaded all necessary drivers, and Arduino library needed to get the Shield up and running on TechToys’ GitHub page.

Bring HDTV Capability to Small MCUs with TechToys’ HDMI Shield was originally published in Hackster Blog on Medium, where people are continuing the conversation by highlighting and responding to this story.

Original article: Bring HDTV Capability to Small MCUs with TechToys’ HDMI Shield
Author: Cabe Atwell