Norns shield - issues with hotswapping grid? [SOLVED]

I’ve been trying to create a setup where I share a grid between Ansible and my Norns Shield. I’ve been using a simple USB switch:

Most of the time it works absolutely fine for switching between, say, Kria on ansible and MLR on norns. It can work for several minutes and lots of back and forth, but then randomly it’ll stop working on the Norns. The little burst of light in the corner of the grid still comes on, and Ansible continues to work, but the norns grid won’t show. On top of that, this seems to crash something in norns. Specifically, the screen remains frozen and no button or encoder inputs work. However, the device keeps processing sound as it should. I am able to open “norns.local” in a web browser but it says “not connected to matron”. I am also able to ssh in and the unix prompt comes up fine, but I’m not sure what to do next to diagnose the issue.

Any thoughts?

(EDIT: I’m using the official power supply and a fast SD card by the way.)

Ok - it’s now doing the same thing even without the USB switch and just a grid and Norns. Matron crashes some of the time the instant I pull the usb cable out.

sorry to hear about the trouble :confused:

this is assumed fixed in the last update — can you do a quick check to verify your software is up to date? SYSTEM > UPDATE

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Oh thank you! I was sure I was on the latest update but wasn’t (I think I forgot to update after a second reformat of my SD card - doh). I’ve updated now and it works like a charm. :pray:

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Just a quick follow-up in case anyone else is looking at the same setup… this switch works, but unfortunately on my system at least, introduces a lot of high pitched electrical noise into the signal chain when there are grid LEDs lit (which I don’t get otherwise). I’m guessing this is because it’s wired for the two USB sockets to share earth perhaps? Anyway, beware - your mileage may vary!

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No USB switch over here but getting noise that sounds like what you described on my Shield + Grid when many LEDs are fully lit. Proper replacement caps on grid.

Let me know if you ever vanquished that noise! :cowboy_hat_face:

No, I stopped using the switch for this reason. It might be unrelated, but I have noticed that the noise floor on the norns shield output is hugely affected by what power supply you use. The best I’ve found so far is the “official” raspberry pi one. I have another one which actually came with a raspberry pi kit and it’s massively more noisy on the output of the shield (like unusably so). Anyway… definitely worth trying every power supply you can get your hands on to see if it fixes any noise problems…

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