Mpi3508 GPIO HDMI screen

Hardware
1

mpi3508 GPIO HDMI screen.
The question is:
If I use an All-in-one Zynthian board (with MCP23017), can I use a generic mpi3508 GPIO display via GPIO?
My full setup is:
pcm5102 audio DAC- this one uses pins:

SCK         > Not wired (Internally generated)
BCK         > PIN 12    (GPIO18)
DIN         > PIN 40    (GPIO21)
LRCK        > PIN 35    (GPIO19)
GND         > PIN 6     (GND) Ground
VIN         > PIN 2     (5V)

MCP23017 uses:
Pin 3     >  GPIO 8
Pin 5     >  GPIO 9
Pin 8.    >  GPIO 15
Pin 10.   > GPIO 16
Pin 36.   > GPIO 27
Pin 37.   > GPIO 25
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The reason why I want to connect the screen with a use of GPIO instead of HDMI is that I HDMI option requires an HDMI cable that will not fit inside Zynthian case, and a usb touch screen cable, that will not fit inside the case either.
The case I’m using is a 3D printed version from zynthian-case/3DPrinted_Waveshare35 at master · zynthian/zynthian-case · GitHub

An MCP23017 All in one board I’m using is:

3

Previously I’ve used a diy plywood case that was quite larger and the 2 RPI4 hdmi sockets, RPI audio 3.5 socket were not exposed. So all the connections and wires were inside the case.

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Hi @sinitsinmike, I guess there will be no GPIO conflicts as the display use HDMI for the video signal (other 3.5 inch displays usually use the SPI interface wich “consume” a couple of GPIOs).
But I’m not 100% sure about this as the documentation lacks informations about this.

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Hello. I specifically need to use GPIO for video, not HDMI, becasue those cables are sticking out of the case. When using gpio there’ no cables sticking out outside the case.

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This display use HDMI for vidéo signal.
Thé GPIO header is for touchscreen and power supplu feature

1 Like
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I guess I’ll have to order a different one :slight_smile:

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For what it’s worth: There are a lot of choices for HDMI, USB and Ethernet to use flat and-or slim cable:

or just google “flat hdmi cable”.

1 Like
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Thank you!
I kind of set my mind on a specific case. Wanted nothing hanging outside that case. Perhaps this is not possible. Perhaps I have to look at other 3d printed cases.

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May be I can get a display that connects with a flat ribbon cable from LCD to the special connector on PRI board.

11

About these HDMI connectors, they exists in 90° or -90° too wich consume less space but from my experience the little plastic lock is really fragile (I have broke a couple of them) and I finally found that solution not so convinient and a bit expensive.

because, for quiet the same price of a 3.5 inch 480x320 display you can get a 5 inch DSI 800x480 dsplay.
Only one flat cable is needed for power touch and video signal: