8-inch digital audio output

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1

Hi!

I’m completely new to this so maybe it’s a stupid question.
I bought the 8", IPS, 1024x768, HDMI display kit and the Adafruit I2S 3W Class D Amplifier Breakout. I was thinking of building a miniature screen tv with a speaker that would play video and sound from the HDMI cable. On the driver board to the display there are som “digital audio” pins that I thought could be connected to the adafruit breakout board to get some sound. Is this possible? If so witch pins go where?

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Thanks

1 Like
2

I could be wrong, but I’d reckon:

LCK  -> LRC     Left/Right clock
BCK  -> BCLK    Bit-clock
DATA -> DIN     Data
N/A  -> GAIN    Check the amp datasheet/docs for this pin
N/A  -> SD      This is the ShutDown pin to disable the amp
GND  -> GND
5V   -> Vin

SPDIF is a different protocol/interconnect from the I2S pins.

3

Thank you for your reply.
Unfortunately I haven’t got it to work. When I connect the HDMI to my Mac mini I can’t find the HDMI in the sound settings. Maybe it’s not possible…

4

I’m curious also how to get audio out of the drive board.

5

I used the same Adafruit i2s breakout as above, and had to uncommitted a line in /boot/config.txt rebooted and all working OK.

hdmi_drive=2

More details here

6

Hey there,
So you found a solution for wiring the amp to the lcd driver board? Can you let me know how you wired it up? I’m trying to do the same thing. It sounds like even after it was wired correctly you had to make some script changes on you Pi.

I’d appreciate any help you can offer here.

Thanks!

7

I connected it was @gadgetoid suggested and removed the # in the line I quoted in my post above in the config file in /boot partition. Rebooted and it should have worked

8

Ah! Thanks. So I’ll wire it as @gadgetoid suggested and make the changes to the config.

To confirm you didn’t wire anything to the GAIN or SD pins?

Glad to see an example of someone making this work.

Thanks again. I’m going to try it tomorrow.

10

Having the same issue. the wiring suggested by gadgetoid is correct. But after going back and forth with Pimoroni through email, it seems like no one really knows whats going on with the digital audio out pins on this driver board.