Pi Zero W GBA [BUILD]
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I also need to remove the board from screen. There's a few resistors and capacitors, are they going to mess me up it I connect the screen solely from the ribbon cable? Also I need a schematic showing which ribbon cable pins are what, since there are untraceable.
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@techieandroid the board will have most of its components for the SD card. There will be a resistor for the backlight, and a FET/transistor to allow you to pwm backlight.
I made a simple board that it designed for 14 pin versions of the screen (2.2 inch, no touch)
https://oshpark.com/projects/BP9tGKagBut larger screens have touch, and so I designed this board
https://oshpark.com/projects/zUNmnlLFThe pads on the back are for the touch interface, which most folks don't use. I have not tested the latter board, but I see no reason why it wouldn't work.
Either board needs a smd resistor, 0805 in size, and just 10 ohms
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@techieandroid In my build I don't use the top pin, sdo(miso).
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@techieandroid my board has the led pin tied to the 3.3v to simplify things. It means you can't adjust the backlight without changing the resistor. Saves you a wire 😀
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Okay thanks guys I'll check that out. So I can't be sure but maybe the buttons on the right side ground to the same location as the a-gnd (in the pic it's at the end of the alligator clip) which I believe to be the audio ground (speaker probably). And on the left side the buttons could ground to the same spot as the ground for the cartridge. I need to know because this won't work if I cut the center out and can't ground the buttons.
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Okay I cut my miso cable and the led cable and connected the led to vcc. What was miso doing since it seems to be working fine without it? And giving the backlight 3.3v makes it look better imo. Thanks for the tips. I'm going to test around on the GBA board and see if I can locate ground.
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YES! I've found the remaining information I needed.
Button programming
https://www.raspberrypi.org/forums/viewtopic.php?f=78&t=83317&p=589292#p589292GND location
https://assemblergames.com/threads/game-boy-advance-schematic-cadsoft-eagle-files.54814/I will be completing my project tonight. :]
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Shoot. I desoldered the screen from the board, mapped out all the traces, soldered to the ribbon cable successfully and it didn't work. Tomorrow I'm going to solder it back to the board, test it, then connect it a bit differently. I'm not giving up. I'll post pics later.
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@techieandroid the screen will have this pinout
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@moosepr
Um it doesn't look right to me. I will upload my schematic to show you what mine looks like. -
@moosepr
Wow. I've been so busy. I finally have time to finish this project.
Your pinout matchs up with mine. 10-18 though, I have no idea what each is for unless they operate the touch sensor.
1-9 is what I had connected that didn't work.I've soldered the screen back to the board successfully and now all that happens is the backlight gets powered, nothing else.
I've tried the 3.2" model too and without knowing what SCK (SCL) is and where it is I've left it not connected. Now all that happens is a powered the backlight.
I need a reference guide to what names mean the same on the pins since they are all named something else on different boards.
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https://goo.gl/xTw5Lj Here are my pics
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@techieandroid ok, so the last 4 pins are for touch, then all the led pins are for the backlight. Try this
Display--------Raspberry Pi
SCK------------pin 23 (GPIO 11)
SDO----------pin 21 (GPIO 9)
SDA----------pin 19 (GPIO 10)
CS--------------pin 24 (GPIO 8)
RST------------pin 22 (GPIO 25)
D/C-------------pin 18 (GPIO 24)
VIN-------------pin 17 (3.3v)
GND-----------pin 20 (GND)
LEDA----------3.3v via a resistor (10 ohm is enough)
LEDK1-4-----GND -
@moosepr
I thought you'd let me know what SCK was on my other screen (the 3.2")... Let me grab a pic so that you can see it.As far as what you have there, I already knew what GPIO pins to use, that's how it was working before I separated the 2.8" one from the board.
I don't need LEDA or LEDK1-4 because I wasn't using them in the first place.
Hope that clears things up.
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I don't see SCK on this board so what is it labeled as? Or am I wrong, do I not need SCK?
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@techieandroid i was talking about the bare ribbon on the 2.8" screen
Im not sure on the 3.2" screen, there is 'CLK' up in the top right, but that may be just for the SD card slot (along with the MOSI and MISO)
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@moosepr
Okay, maybe I'll figure it out. I don't think CLK is it since the pins are grouped, I believe those four up there are just for the touch screen.
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