[WIP] Gameboy Printer

Hopefully someone here can help me out a little. I have been trying to get a gameboy printer to work with pokitto but I have had only limited results.
From what I can tell, I am doing everything right, but I’m getting into a situation where the printer malfunctions and refuses to print any more than a 16x16 block (the printer is being sent a full ‘line’ of 64x16 data).

If anyone has done this with arduino perhaps, maybe they can have a look at my code to see where my mistake is?


I dont have a gb printer. Where in the code does it stall?

The printer will initiate ok, it accepts 240 bytes of image data and replied that the buffer is full. I send the print command, the printer accepts it, starts printing. However it only prints the first 32 bytes then returns multiple error and stops.

Two words: logic analyzer

no I’m kidding. thats pretty heavy weaponry for this

can you send the data in smaller chunks?

I have it hooked up to an analyser, the data is sending ok. Sending in smaller chunks won’t help much as the print command won’t work until the buffer is full.

I think I’ll have to set up an Arduino version and test some of the existing projects to see if I’m missing anything. - I don’t have a real Gameboy to test with.

Is it possible you are missing some sort of a buffer termination character?

According to the internet you need to send an empty data packet, which I am doing. Apparently it won’t even attempt to print if something is wrong.

Hopefully this is of some help:

Also, are use using 5V / 3.3V level shifters?

No need for shifters, both are communicating with each other fine. I just seem to be missing something in the conversation.

Well after getting the same issues with arduino, it looked at my power supply. Turns out I was getting a genuine low battery warning, I thought my 9v power supply would be fine, turns out it wasn’t.

The code seems ok. :stuck_out_tongue:

[edit] For anyone wondering why I didn’t suspect the power supply at first, there is an easter-egg on the gameboy printer that when you hold the feed button when powering on, it prints ‘Hello’, this was working fine so I assumed the printer had enough power to work properly.

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Lets 'av a video mate!!!

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Might be a little while, need to make the code do something other than dummy data.

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Is there still an issue with getPixel? I’m reading pixels and attempting to convert them to gameboy format, but each 8x1 line seems to be half back to front.
So I have to convert the pixels from