I like the idea of offloading audio connection to a seperate card with single connecting cable. Do allow for audio in/out and possibly multichannel audio. Maybe it would make sense to place the DACs and ADCs on that card with I2S & I2C connections allowing flexibility in what expansion card is used. The initial default would have the 2 x output PCM5102 but could be exchanged for more complex audio i/o card.
It looks like you have found the info on eurorack format but remember:
Left and right holes are not equidistant from their corresonding edges.
Vertically centre the PCB on the frontpanel.
Avoid horizontal overhangs of front panel.
Skiff enclosures may accept cards up to 40mm deep but that may not be across full height of card. Indeed my Behringer is shallower at the lower edge (due to the angle of the case).
I like the idea of offloading GPI and ADC expansion to a dedicated card that could include the electronics and connectors.
You got it. Literally about to place an order for boards for my business this week so Iāve already got a set of 5 of both the main board and fascia in my cart already.
Figure I can do a set of both for $20 including shipping looking at it right now. Iāll be keeping one set for myself (clearly) but the other four are up for grabs.
Yes, Iām in the US. Iāll have to look into shipping to Italy but itās probably doable. Probably not super cheap, but should be cheaper than buying 5 sets of boards
Hi Stojos
thanks for putting this together. It was a lot of fun building. I ordered the second 5" display you recommended. While the outer holes do match, the inner ones do not. The build guide tells me to remove the screen posts but I do not know how? They are very tight on there. I tried with a pair of pliers but to no avail.
You are right. Internal posts are not used and they need to be removed. I removed them all. I do it with pliers. They are not screwed. They are just pushed into screenās PCB and glued/soldered. Remove them with pliers as you would if you would remove somebodies tooth. Wiggle little bit left and right and then get it out trying to protect the surface of PCB as much as possible. There is no important traces around the posts. Please do not take this wrong way. I donāt imagine that you are dentist or a weird person
Hi Guys, I am looking to add audio in hardware to mini but I could not find well supported affordable alternative as we have for audio out.
I looked first to integrate readily available i2C ADC PCM1808 but that one need external clock source and I could not find kernel overlay for it.
There is another alternative using waveshare WM8960 audio hat - not that affordable but still third the price of cheapest hifiberry DAC ADAC cards and with decent raspberry pi support. Did anyone try this one ?
the vaweshare is entry level in term of perf but has a versatile chip with built in mems mic, amp and so on. I canāt tell for the software support, I guess it should be OK.
But, in the same manner the raspberry codec pi zero should be a better choice
Both are comparable to wm8731 chip, wich is an old friend of the raspberry pi ecosystem (know as audioinjector). Search the forum for wm8731 or audioinjector, youāll get a lot of stories
pcm5102+pcm1808 is the way to go imo. pcm5102 has much better perf and is supported. Both chip are damn simple and fully hardware configured, so simple device tree based on spdif-dit and spdif-dir should run.
Iāve started with this:
And tried to make run with some aliexpress modules, but as you mentionned, it lacks the external clock.
So Iāve already designed a small board with those chips, the oscillator, good voltage regulators. In a format that fits my needs, but I ask myself if a kind of real simple evaluation board wouldnāt be better for getting started.
Design is quiet simple and can, why not, be duplicated for investigating multichannel audio.
Also see here:
With better specs (and higher price) thereās the CS4272 from Cirrus Logic wich has a device tree driver āsuperaudioboardā
Finally the TAC5242 looks promising. But is not for sale yet.
PCM5242 is interesting due to simplicity. However, it is interesting why adc was not implemented on this card that is using it.
It looks like that I will need to continue with pcm5102+pcm1808 approach. I assume that due to pcm1808 external clock pcm5102 will have to be in that mode as well. There is a project on GitHub that managed to get it working on rpi4. It include schematics too and code for driver.
I own one IQAudio like this. Itās really great value (excellent specs and lots of connectors) for the money and itās officially supported by Raspberry PI. But, its not really low cost.
yes Iāve pointed it here
Iām not sure the method he use for registring the driver is still valid. There where many changes in the audio side since kernel 5.19 (more or less at time he published his project)
Now, most of the Hat (that are actively supported) tend to use the simple-audio-card driver, and and there is no more master/slave, but clock producer and clock consumer.
From what I understand : Now that RBPi5 has a decent pll generator, he can act as a clock producer, while with Pi4 it was the codec the producer.
PCM1808 use HW configuration pins for choosing the working mode while I"m quiet sure PCM5102a doesnāt need any hw config. If an external clock is provided, he will act as consumer.
All through holes are on the top side, with jumpers for configuring the working mode and slide switches for changing input impedance (not yet implemented)
Headers are for adding input filters with adjustable gain with the 2 pots. SMD are on bottom, jumpers are for routing audio to the jack: stereo in + stereo out or full differential input. FPC connector is for the upper control board
Yes, I spotted that too. Hence my hesitation originally to go this path.
Hm it looks like that I will need to build this and try to make working driver. I will first try to build this as per schematics from GitHub and only if getting driver working I will try to do the same with using combination of two cards plus a oscillator (if rpi canāt produce a clock). These two cheap cards have most of components that are in schematics so I believe that combination of these two plus clock should work and that would be very affordable option for mini.
if you would like to help me with a driver development I can send you assembled card. If we are successful we can ask @jofemodo to include driver inside zynthian build instead of explaining to user how to compile and configure it.
Of course Iām ok to help for the driver. Iām sure that it would not be a great issue. I dont know what you mean in assembled card. I was thinking on a very basic one just for prototyping.
[edit]too enthusiastic I didnāt read your post carefully |/edit]
Thanks for the video, that did the trick. It is actually quite satisfying to remove them:)
I guess this pcm5102 card does not have any mixer, so that is why the audio levels do not work? Should the SCK jumper on top be bridged or not?
Audio level is software managed inside zynthian mixer. By default there is sound because by default main chain inside mixer screen is set to 100.
First check that card is properly configured at the back. There are earlier posts on this thread what configuration should be:
Then check that card is not faulty. I did get one where audio connector was not properly soldered on the card. This was only for one channel. I never had issue where both channels. Resoldering solve the problem. if you use connector from zynthian mini pcb than this should not be an issue.
Hi Stojos
Audio works fine, just the Audio Levels Screen in zynthian does not work, it is empty.I did solder the 4 jumpers like this, but did not know if I should bridge the sck jumper pad on the other side as well.
Ah, you are right, I am not sure what you could do on audio levels screen. I use that screen only for controlling audio in gain for cards that comes with adc. I am not sure what would be the purpose of audio screen for such a simple card that do not have adc, neither headphone hardware.
The Audio Levels view provides control of the audio hardware including input / output levels, connection type, etc. only the parameters supported by the loaded driver are presented. For the V5 it includes the assignment of the TRS signals, etc. For the PCM5102 there is no control so the page is empty. Only audio signal is connected via I2S. There is no control, e.g. via I2C.
|/edit]