Ubercorn Chaining

Hi All

Have searched the forum but can’t seem to find any good answers on this - chaining together ubercorns… I have the daisy chain cable from pimoroni and I am attempting to run the uber corn 2x1 sample but I only ever get one panel to display.

I see there are DIP switches for setting an address but toggling those don’t seem to help matters.

I have adequate power supplied to both boards which I’ve verified.

Can someone suggest what I’m doing wrong, do I need to spec the address in the code?

I have to ask the obvious, second board also has the power wired up?

Hi yes I have verified 5v to the other board via the ‘site power’ posts

Ok, I don’t own one so I don’t know what to look at or for.

Thanks for replying alpha, I hope the Pimoroni crew can shed some light on this…

Well it seems there’s little to no support on this, I had hoped for more from the forums (*Pimoroni crew!)

We can try an @gadgetoid and @sandyjmacdonald. I could have sworn I saw a post by pimoronicrew or something similar in another thread but can’t find it now.

Hello! Sorry for the radio silence…

You do indeed need to specify the addressing. We have an example of how you can run two Ubercorn matrices together here: https://github.com/pimoroni/unicorn-hat-hd/blob/master/examples/ubercorn-rainbow-2x1.py

I can’t recall if the addresses start from the left hand side or right hand side of the switches, but they’re binary, so 0 (the first panel) is all of the switches down, 1 is either the right hand or left hand switch up, and so on.

Hope that helps!

It’s left to right, I’ve just been told. 🙂

Thanks for getting back to me Sandy I’ve been in the lab all day setting up for a STEM event tomorrow so I will be in early and will take a look!


Hi both,

Did you manage to resolve this? I’ve just taken delivery of 4 Ubercorns. I’m using a Pi 3 and each board works perfectly if it’s directly connected to the Pi. However, if I connect a second board using a data cable and power cable the second board will never light up.

I’ve checked I have power and I’ve tried ever combo of binary addressing I can see, but nothing ever works for the chained board. Is there something simple I am missing?



@NAnderson, @td4dotnet: I’ve just hooked up a couple and have the switches all down on the first Ubercorn, then switch 1 in the up position on the second Ubercorn. I’m using the ubercorn-rainbow-2x1.py example from the GitHub repo without any modifications.

This is what I’ve setup here.

Senario 1:
First Board: All switches down. Second board: 1st switch up. = First board lights up. Second board dark.

Senario 2:
First Board: 1st switch up. Second board: All switches down. = First board lights up. Second board dark.

If I swap the Pi onto the other board the board with the Pi will light up, but the other board is dark.

I’ve tried it all off one power supply and also with a second 2.5A power supply injected into the second board. In both cases, the board with the Pi lights up. The second board is dark.

Is there something else I need to be doing?

Should I return the parts as faulty?

It’s hard to tell from the photo, but is it possible that you have the data cable plugged in the wrong way? The connector on the cable has a little lump on one side that should slot into a notch in the female connector on the Ubercorn board. My short data cable looks a little different to yours, in that there’s no kink in it when the two boards are side-by-side.

Further to that, it’s entirely possible that your cable has had one connector put on it the wrong way round. Be aware that if that is the case, then you can’t just rotate it 180° to correct the problem.

I presume you got a few data cables if you bought four panels? If so, then have a look at the others to see how their connectors look, and try swapping them.

I can confirm that the first panel in your chain (with the Pi attached) should have all the switches in the down position, and the second should have switch 1 in the up position.

I bought four cables and they are all identical. They match the orientation of the plugs on the product photos on your website too. However…

you are absolutely correct. The plugs on one end of all four cables (and on your website product photo of the cables as far as I can tell) are on back-to-front (facepalm emoji if I had one).

I deconstructed one of the plugs, re-crimped it back together and boom, everything now works.

Any idea what I do now with the faulty cables? And also what I should do with the Ubercorn that has the broken ‘IN’ socket? (Some of the tiny joints holding the socket to the board are now broken because I had to plug-in/plug/out these faulty cables so many times).

If you hadn’t mentioned the cable might be the issue to me I honestly don’t think I would have ever worked out what it issue was (I would have simply trusted that the professionally produced cables were correct) - thank-you so much for the prompt!!

As a temporary fix for the broken IN socket I’d just swap the positions of the two boards. Mount your Pi on the one with the broken IN socket. That will switch your cable over to the other socket(s). Don’t forget to change the ID switches. ;)

Thanks - that’s exactly what I did and it worked a treat as a short term fix.

@NAnderson Erk! That’s not so good, but I’m glad that I sussed it out.

Could you do me a favour and take a photo of a cable, with the knobbly-bits on the connectors visible and also of the two connectors on your Ubercorn boards with the slots on the connector shrouds visible. I just want to make sure I know what’s going on before we try to fix it…

We’ll refund you for the cables and refund/replace the panel that you’ve destroyed too.

Oh boy… this is a weird one, but I think I know what’s going on… 😆

The cables are correct, but the left hand connector shroud is on the wrong way. You can try to carefully slide the plastic shroud off, rotate it 180°, then push it back on. If you have a soldering iron, you can try to remelt the joints on any pins that have come loose.

As I say though, we’ll happily refund you for the panel or replace it, and if you can fix the broken one when you’ve got an extra one for free!