M5Stack's Atomic Display Base Gives Atom Boards an HDMI Output — Through Clever SPI LCD Emulation

On-board Gowin FPGA presents itself to the host as an SPI display, but spits out up to an 720p60 HDMI signal at ~16fps.

Gareth Halfacree
2 months agoDisplays / HW101 / FPGAs

Embedded and hobbyist electronics specialist M5Stack is bringing HDMI-compatible video outputs to its Atom family of all-in-one development boards — with a clever gadget that turns almost any HDMI monitor or TV into an "SPI" LCD: the Atomic Display Base.

"Users can pair [the Atomic Display Base] with the Atom series hosts to meet different memory and application requirements," M5Stack explains of the unusual device. "The Atomic Display Base can replace the traditional PC control solution for display panels, providing a more cost-effective option. It is suitable for applications in industrial control displays, smart home information screens, education and conference presentations, and remote monitoring displays."

M5Stack has brought a 720p HDMI output to its Atom family, thanks to the clever FPGA-powered Atomic Display Base. (📹: M5Stack)

The way the Atomic Display Base delivers an HDMI output from devices never built with such functionality in mind is unusual, to say the least: the gadget includes a Gowin GW1NR-9C field-programmable gate-array (FPGA) on board, loaded with a firmware that emulates an SPI-connected LCD panel — outputting RGB video to a dedicated HDMI controller.

To the microcontroller host, the display seems to be a perfectly normal SPI panel; to the HDMI display, the connected gadget seems like a perfectly compliant HDMI device — though, M5Stack warns, the output resolution may not match the display's expectation, and if the display doesn't support adaptive scaling of non-standard resolutions issues may occur.

The Atomic Display Base is capable of outputting a 720p60 (1280×720 at 60Hz) video signal with "optimized frame rates" up to 12-16 frames per second (fps), without audio, from any Atom-format development board — including the company's Atom-Lite, Atom-Matrix, Atom-Echo, and latest Atom-S3 and Atom-S3R families.

The Atomic Display Base is now available to order from the M5Stack store at $19.95; additional information, including a schematic, is available in the company's online documentation. The device is supported in the Arduino IDE and Espressif's own ESP32-IDF, M5Stack says, though not yet in its own block-based UiFlow environment.

Gareth Halfacree
Freelance journalist, technical author, hacker, tinkerer, erstwhile sysadmin. For hire: freelance@halfacree.co.uk.
Latest articles
Sponsored articles
Related articles
Latest articles
Read more
Related articles