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Need help finishing USB audio DAC

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chrisjohan

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Hi. I want to build an USB audio DAC, for my raspberry pi project.

I want it to have stereo speakers, but changing to the headphones when I insert them. I'm using the CM108: https://datasheet.lcsc.com/szlcsc/1912111437_Cmedia-CM108AH_C371346.pdf

This is my schematic so far:

I would be very grateful if someone could help me. How do I connect the rest of the pins?
 

Hi,

In your schematic the device has 48 pins, you just connected 7 pins.
So you ask us how to connect the remaining 41 pins.
(This means we should do about 80% of your job)

Nobody could do this without reading the datasheet.
I recommend you do this first.
Many of the pins will have a clear description how to connect them - even when unused.
Please do/try the main job on your own.

You are welcome here with a more complete datasheet.

I assume the vendor has some application note, design note, example design.
At least there should be some schematics in the internet.

Klaus
 

Ok, I understand. I'm sorry. But can you help me with one thing? I'm trying to understand, but I can't figure out how to connect so the audio switches to the headphones when I plug them in.
I've found a board that uses the CM108 chip: https://kameya-z.way-nifty.com/blog/2015/06/cm108usb-dac-cf.html
It looks like the speaker output are connected to the "AVDD1" pin. Is that correct?
 

Hi,

In the link I see just (chinese) symbols. No schematic.
Sorry, I can't help.

Klaus
 

Sorry, I mean the picture on that site.
How does the switch between the speaker output(middle) and headphone(top) work?

cm108b.jpg
 

There has something to do with the MODE pin, right? But I don't know how to connect it all.
Can someone please help me?
 

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