The UK based crew from Batsocks develops and sells open source kits including breadboard related projects. We found a project they call the Tellymate which looks like a simple and easy way to provide plug-in video text output to any MCU project using just an ATmega8 and a handful of passive components.
TellyMate is a ‘terminal display’ device that takes serial data and outputs text to a TV screen. We’ve (primarily) designed it to perform as a display/debug device for other electronics projects. In that respect it performs a similar function to a ‘LCD + serial backpack’ that we use, but with more characters.
* Input: RS232 Serial data (autobauding)
* Output: Composite video (PAL or NTSC)The aim is to keep the hardware as simple as possible – an AVRMega8 and a 16Mhz crystal. The software should allow the display to be controlled via simple control codes. The output signal shouldn’t be interrupted in any way whilst receiving or processing input.
Batsocks has completely documented this open source project, which they also have available in kit form. Visit their website for complete information including design details, schematic and source code.