4x4x4 Help.......

Forum for posting topics and questions about anything.
blackzakk
Posts: 16
Joined: Mon Jul 27, 2020 2:52 pm

Re: 4x4x4 Help.......

Post by blackzakk » Sun Aug 02, 2020 3:42 pm

Hi,
Pin 1 U1 to ground gives 5v. It just seems to be pin 22.
I ran the meter across a finished cube and pins 1 and 22 do give 5v and the other pins. Probably why it works.
I assume that the link to the LEDs is pin 22 ?
Thanks again.

Tel ;o))

blackzakk
Posts: 16
Joined: Mon Jul 27, 2020 2:52 pm

Re: 4x4x4 Help.......

Post by blackzakk » Sun Aug 02, 2020 6:02 pm

Hi,
Update: Gone back to the drawing board and took off LEDs for easier access. I get 5v on pins 1 & 8, 7 &8, 8 & 22, There is continuity between the crystal pins and UI 1.
Put LEDs back on and still no joy.

Tel ;o))

andrew
Site Admin
Posts: 1374
Joined: Sun Aug 05, 2012 4:15 pm

Re: 4x4x4 Help.......

Post by andrew » Mon Aug 03, 2020 1:11 pm

I get 5v on pins 1 & 8, 7 &8, 8 & 22,
Ok, I'll have a rethink based on this information but before I do can you confirm pins 8 & 22 as these are both GND pins so you shouldn't see 5V across them.
Comments made by this poster do not necessarily reflect the views of Hobby Components Ltd.

blackzakk
Posts: 16
Joined: Mon Jul 27, 2020 2:52 pm

Re: 4x4x4 Help.......

Post by blackzakk » Mon Aug 03, 2020 2:47 pm

Hi,
Sorry, miscounted. 0v on 8 & 22 and 5v on 8 & 23.
Wouldn't there be a way to "jump" the connection with a small piece of wire ? Or at least check if current could reach the LEDs ?
I'm probably talking cobblers but it's just an idea.

Tel ;o))

andrew
Site Admin
Posts: 1374
Joined: Sun Aug 05, 2012 4:15 pm

Re: 4x4x4 Help.......

Post by andrew » Tue Aug 04, 2020 8:49 am

Wouldn't there be a way to "jump" the connection with a small piece of wire ? Or at least check if current could reach the LEDs ?
You could try connecting one of the legs that connects to sockets P17, P18, P19 or P20 to GND.....
4x4x4_Image2.jpg

Be sure only to connect these pins to GND and also not to short any other pins. If the microcontroller is running and the problem is with IC2 then some of the LEDs on the cube will start to do something.

Failing that, based on your recent measurements, everything looks sensible which leaves very little left you'd be able to check with a meter so we may have to look at plan b.
You do not have the required permissions to view the files attached to this post.
Comments made by this poster do not necessarily reflect the views of Hobby Components Ltd.

blackzakk
Posts: 16
Joined: Mon Jul 27, 2020 2:52 pm

Re: 4x4x4 Help.......

Post by blackzakk » Tue Aug 04, 2020 2:15 pm

Hi,
Just finished the green cube and it works. Fantastic. So, now I have blue and green cubes.
Right, connected pins 17, 18, 19 and 20 to ground and the corresponding led on vertical layer 3 lights up. So, the top one, next one down, next one down and next one down. So, it lives !!!. No other LEDs light up though, so I'm hoping this is a positive thing. (Sorry about the pun.)
If this doesn't work out then don't worry. I can't thank you enough for your unending patience and the fun I've had putting the cubes together and seeing them do their thing. I'm still hoping, though, that the little bugger will work.

Tel ;o))

andrew
Site Admin
Posts: 1374
Joined: Sun Aug 05, 2012 4:15 pm

Re: 4x4x4 Help.......

Post by andrew » Wed Aug 05, 2020 8:22 am

Right, connected pins 17, 18, 19 and 20 to ground and the corresponding led on vertical layer 3 lights up. So, the top one, next one down, next one down and next one down.
Hmm, unfortunately that's not what I was expecting to happen. Connectors P17 to P20 provide a GND to each entire 4x4 horizontal layer via IC U2. If the problem was with IC2, by grounding one of those 4 connections should have caused the LEDs on the corresponding horizontal layer to start flashing. Albeit in an indiscernible pattern.

Do any of the LEDs flash rather than permanently light up when you do this? If so that would at lease confirm that the microcontroller is running.
Comments made by this poster do not necessarily reflect the views of Hobby Components Ltd.

blackzakk
Posts: 16
Joined: Mon Jul 27, 2020 2:52 pm

Re: 4x4x4 Help.......

Post by blackzakk » Wed Aug 05, 2020 12:39 pm

Hi,
No, just the one LED on each vertical layer. I have tested each LED and a couple light up the four vertical line rather than just that one LED.
I'm really tempted to buy a bag of the blue LEDs that you sell and remake the LED set up and make sure that it is all connected properly. The last cube I did I checked at all stages. This one I didn't. Maybe that could be the problem?

Tel ;o))

andrew
Site Admin
Posts: 1374
Joined: Sun Aug 05, 2012 4:15 pm

Re: 4x4x4 Help.......

Post by andrew » Wed Aug 05, 2020 3:12 pm

No, just the one LED on each vertical layer. I have tested each LED and a couple light up the four vertical line rather than just that one LED.
That's defiantly not what I would expect to happen so something is very wrong. I would expect either that all the LEDs on the layer you grounded the pin for would flash on and off in various patterns or, none of the LEDs would light at all.

Do any of the LEDs that do light actually light up flash at all or are they permanently on?

Can I just also sanity check that you are grounding the pins I circled in red in this image....

Image

...and not the actual pins on the IC.

I'm really tempted to buy a bag of the blue LEDs that you sell and remake the LED set up and make sure that it is all connected properly. The last cube I did I checked at all stages. This one I didn't. Maybe that could be the problem?

TBH I doubt very much that it's the LEDs that's the problem because the only way I can think where there could be a problem with the LEDs that would cause all of them not to light is if they were all the wrong way around. Assuming you're doing the above test at the correct place then the fact that some are lighting means that can't be.


One other option before resorting to buying more LEDs is that we can look at getting the PCB part of the cube back and I can have a look at it myself.
Comments made by this poster do not necessarily reflect the views of Hobby Components Ltd.

blackzakk
Posts: 16
Joined: Mon Jul 27, 2020 2:52 pm

Re: 4x4x4 Help.......

Post by blackzakk » Tue Aug 11, 2020 4:57 pm

Hi Andrew,
I've checked everything you've asked and no change. So, I've ordered and received another red cube and will put the pcb together and then transfer the LEDs from the dodgy one onto it. If it works then there's definitely something adrift with the pcb and components or my soldering them.
I'll let you know how I get on. It could be an idea to send you the pcb for you to look at if it isn't too much trouble.
Stay safe.

Terry

Post Reply

Return to “General Discussion”