#1371

Hi, I have a question regarding the input impedance of the shield. The norns hardware informations state that the input impedance is 10k, but if I calculate the inpute impedance of the shield according to the data sheet of the CS4270 (adding R7 and R8) I get 4.8k. Does the input impedance of the shield simply differ to the Monome built Norns or am I making a mistake somewhere?

I am asking simply out of academic interest :grinning:

Thanks!

1 Like
#1372

hi! I cannot find anywhere in Italy or EU the Cirrus Logic CS4270-CZZ. Looking on eBay I found two different dealers selling the chip but they reported on the surface different codes, should I worry about?

Link 1

Link 2

Anyway, if there is anyone whoā€™s got a spare one Iā€™d be interested :smile:

#1373

Iā€™d try Aliexpress in this extreme case. A friend of mine is in the search for one and he ended up buying from the Chinese portal.
Every component I purchased there came out perfectly fine.

#1374

aliexpress
not the best solution

#1375

I agree.
I only bought there when I couldnā€™t find any stock and itā€™d take a lot of time to be back on it.

#1376

I ordered these from ebay:


I hope they work.
Will report as soon as I know. Donā€™t know when i will have all the parts and build it.
#1377

take advantage mouser

#1378

Mouser is out of stock until May of next year

https://www.mouser.com/ProductDetail/Cirrus-Logic/CS4270-CZZ?qs=bUPhaerQQeFhRaSYlj1lyg%3D%3D

#1379

large new batch of shields are being assembled now. iā€™m expecting weā€™ll be shipping within two weeks.

5 Likes
#1381

Does someone have some input on this?

PS: Sorry for the deleted post, I am not used to the edit functions yet

#1382

it looks like the norns shield has slightly different values. hereā€™s the schem: https://github.com/monome/norns-shield/blob/master/norns-shield-schem.pdf

1 Like
#1383

Thanks, I used this schematic to calculate the impedance. But it seems to be correct then.

1 Like
#1384

The lower 4 digit number is the date code

Iā€™d reach out to them on eBay before ordering to make sure they have them in stock. Ordered some items from overseas in bulk to later have them contact me saying they were out of stock and price was actually 5x :money_mouth_face:

#1385

Noob here
Iā€™ve spent some time on this thread but i was unable to find a link to a compatible Pi to purchase to add to my BOM
is this compatible? Thanks in advance?

#1386

No. Pi3b+ is recommended.

Also try Canakit for a Canadian distributor (if mouser doesnā€™t have them)

Mouser link

Canakit

3 Likes
#1387
  • CS4270 update -
    My ebay order got canceled due to ā€˜shipment lostā€™. I got a refund. Ebay prices seem to have gone up elsewhere.
#1388

URGH just tripped over my headphone cable and

IMG_20201116_214817
IMG_20201116_2148172976Ɨ3968 1.44 MB

This is not going to be fun to fix :confused:

#1389

Very fixable - glue and wire as it looks like the pads and traces have goneā€¦ Should be okā€¦

1 Like
#1390

I just bought two from a seller on ebay called ā€œTop-Chipā€ - 7,30ā‚¬ a piece :confused: going to report how that goesā€¦estimated shipping in 14days

1 Like
#1391

Just built a DIY Norns shield and it seems to be working other than Iā€™m pretty sure I got a defective display from Digikey (same missing pixels issue noted by others) and none of the distis has CS4270 codecs. Iā€™ve ordered one on ebay but thats a crap shootā€¦

As expected with no codec on the shield, dmesg shows that the codec is not found and I get a SuperCollider error in Norns because jack and scserver have no audio device.

In the meantime Iā€™m trying to configure Norns to use a cheap USB audio adapter as its default audio device. I plugged the USB audio dongle in, confirmed it is recognized by the OS and tested it with aplay - its working.

From what I see Norns sets up the codec as alsa audio device 0. I remapped the USB dongle as device 0 by adding /etc/modprobe.d/alsa-base.conf which contains:
options snd_usb_audio index=0

I also added /etc/asound.conf which contains:
defaults.pcm.card 0
defaults.ctl.card 0

This appears to be working to some degree - flashing led on the USB dongle indicates its getting data, no SuperCollider or Jack errors but I have no audio from the dongle. Iā€™ve tried adjusting all the audio levels in Norns. If I try aplay to the USB audio dongle it fails telling me the device is busy which it should. If I kill jack aplay works again because jack has released the audio device. It seems so close to working!

I have not changed the devtree so I still get errors about the missing codec on bootup but it seems like Norns should be using Jack, not a specific device driver. What am I missing?