overlay64 - video overlay module

The overlay64 module allows superimposing predefined texts onto an

existing composite signal or onto the luminance portion of an s-video

signal depending on the states of up to sixteen digital input

lines. An LM1881 video sync separator IC is used to detect the

vertical and horizontal sync pulses of the video signal. An Atmega1284

uses these signals to synchronize with the video signal and to

superimpose text on the video display by bit-banging the corresponding

characters over SPI.

The user writes a simple configuration file that determines which

texts are to be displayed for which input line states. The

configuration file is converted to a binary format using the supplied

commandline tool before flashing it to the Atmegas's eeprom memory via

the USB interface.

Device is made by Henning Bekel

Attribution card:

Original project source: https://github.com/hbekel/overlay64

This version allows you to solder inexpensive SMD version of Atmega1284, and has all other features unmodified.

Possible uses:

1) Use with other Commodore 64 hardware to display your own debugging information

2) Use with FPV aircraft system to provide the systems status(AHRS, Autopilot)

3) Computer vision debugging