Project Requirements


STEP 1 - Unmount Tuner TV
Removed elements

STEP 2 - Install & configure RetroPie
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STEP 3 - Connect power, video & audio
⚠ Short thick wires must be used to connect analog video, audio and analog ground to prevent noise. Audio pin use an arbitrary GPIO, I used #12 (GPIO18), a line in your /boot/config.txt will specify this pin. Note that 2 pins must be soldered together on Tuner TV board, it is necessary to force external input mode on A/V jack component.
Tuner TV used pins
Pi Zero used pins
You should now be able to power the Pi Zero with the Tuner TV, video & sound should also be transmited from Pi Zero to Tuner TV analog input. If you have some noisy signal, ensure your cables doesn't cross each other. Oh and the existing A/V input jack has now become an output port, a standard A/V jack to RCA can be used to play on TV.

STEP 4 - Additional inputs
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STEP 5 - Add some polish
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STEP 6 - Add USB port to your Game Gear
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Pi Zero was slightly overclocked to enhance speed on Snes & Playstation emulators, here's what I added in /boot/config.txt: