For last year’s Hackaday Prize, [PK] tried to build a video card for microcontrollers and headless Linux systems. It was only 640×480 resolution VGA, but the entire project was designed around a CPLD communicating with a microcontroller over SPI. This prize entry was, by [PK]’s own admission, a failure. It was late, but now he’s had an entire year to perfect his design. That means he can enter version two of his VGATonic in The Hackaday Prize.
The VGATonic version 2 uses a Xilinx XC95144XL CPLD for the VGA timing, and an ATTiny 2313a to read the SPI bus. Video memory is four megabits of static RAM. That’ls pretty much all you need for the most basic VGA graphics card, and all of this is packed onto a 3×3 inch PCB.
You can do a lot with 640×480 8-bit graphics running at 25FPS. In the video below, [PK] has a ‘hello world’ of sorts, Doom, running on a Raspberry Pi 2 with his SPI graphics card. Yes, it’s a graphics card for the Raspberry Pi, and it looks really good.
Further refinements of the design will include some primitive graphics routines. Not OpenGL or anything fancy, just something to reduce the number of writes on the SPI bus. It’s a great project, and perfect if you want to add video out to an Intel Galileo or other microcontroller project. [PK] has a video demo, you can check that out below.
The 2015 Hackaday Prize is sponsored by: