I have tested a quite interesting breakout board – Serial VGA. It allows to organize multi-windows textual output via RS-232 (TTL) on a VGA monitor.
The maximum window size is 100x50 with 64 colours. It supports up to 9
windows simultaneously. Each window is controlled independently via
special escape (
In general – very useful for small projects on microcontrollers if you don’t bother doing VGA output by yourself (RS-232 output can be implemented even manually if your microcontroller doesn’t support it for some reason). I also tested Serial VGA with Raspberry Pi. The only recommendation is to support the CTS signal line on baud rates faster than 9600. Otherwise the device can loose some characters.