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Intro
The CRT BOY is a simple project that tries to build a Game Boy clone using a small CRT screen. The end result will look like a even more retro Game Boy from the 80ies. The micro controller based on the ESP32 is not so retro is strong enough to emulate consoles from the 90ties.

You should check out the prior relevant projects to have all the details on the esp32 game console componets:
http://bitluni.net/esp32-composite-video/
http://bitluni.net/esp32-composite-audio/
http://bitluni.net/esp32-color-pal/

CRT
The CRT I got from an old intercom is labeled as XG680F . I found similar ones in the google image search and checked the Chinese infos google translated.
https://world.taobao.com/item/39620771319.htm
A similar screen had more specs and info
https://world.taobao.com/item/12491150672.htm

Code
For testing of the first part I have used my Tetris clone https://github.com/bitluni/TetrisSpaceX. It seems to be a bit buggy but I’ll improve the code in the upcoming parts.

Circuit
There is not much to the circuit. The incoming ~12V are routed to the CRT connector and also regulated down to 5V. The micro controller needs to have a 5V pin. Vcc might also be the 3.3V rail so be careful. The 5V will be regulated down to the 3.3V from needed by the ESP32.
The op amp is configured as a simple voltage follower and will only amplify the current. The positive supply voltage of the op amp needs to be higher than 3.3V, otherwise it will cut off and distort the audio. Using the 12V here is ok and takes some load off the 5V voltage regulator.”

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