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Topic: Ran into a problem when soldering some leds (Read 299 times) previous topic - next topic

karthyk

Jan 14, 2021, 08:26 am Last Edit: Jan 14, 2021, 08:36 am by karthyk Reason: File upload
So I am building this 8x8x8 cube where all cathodes are attached together in a layer and every anode is attached to the one above it, it forms a column however when I apply some current multiple leds light up which should not happen. For example if I apply gnd to layer 0 and touch the anode of 2nd column then that only that led needs to light up. I checked for short circuits there are nothing.
https://www.mediafire.com/file/6vvh3wkoyblpp6n/4F043E87-66BC-48A5-9486-B71A9D7C5086.jpeg/file https://www.mediafire.com/file/8bosvzeuwlh2nt3/E9E03609-75C9-44A4-8615-F7889BD4B171.jpeg/file
https://www.mediafire.com/file/8bosvzeuwlh2nt3/E9E03609-75C9-44A4-8615-F7889BD4B171.jpeg/file

UKHeliBob

Exactly which LEDs light up under the circumstances that you describe ?
Is there any pattern to the LEDs that light up if you connect to different columns and the same layer ?
What voltage are you testing the cube with ?
Did you check that every LED in each layer worked as expected before connecting the layers together ?
Please do not send me PMs asking for help.  Post in the forum then everyone will benefit from seeing the questions and answers.

karthyk

Please check the image and sorry about uploading it on mediafire that means you have to download the image for some reason my iPhone doesn't let me attach pics

johnerrington

#3
Jan 14, 2021, 08:41 am Last Edit: Jan 14, 2021, 08:42 am by johnerrington
Can you post a simplified schematic please? (Not 512 leds)  
How are you addressing 1 led? you seem to have x, y but no z.

Sorry karthyk I dont think anyone here will download pictures from an unknown source.
I'm trying to help. If I find your question interesting I'll give you karma. If you find my input useful please give me karma (I need it)

karthyk

https://pin.it/5XSUDdI
This is the schematic there is only x any y if you think about it the z's are all anodes soldered together and x an y is the cathode idk if this clears your doubt maybe it might make you more confused check the schematic it should clear it up

johnerrington

Quote
https://pin.it/5XSUDdI
This is the schematic there is only x any y if you think about it the z's are all anodes soldered together and x an y is the cathode idk if this clears your doubt maybe it might make you more confused check the schematic it should clear it up
To select 1 Led from an xy grid requires x & y selectors.
To select 1 LED from an xyz cube requires x,y,z selectors.
in the schematic X is (say)D0-D8; from J1; Y is from J1 via a 3-8 decoder, enabling 1 led driver.    Z iS from J2;

That is why you have 8 leds lighting up. Or you should have.
I'm trying to help. If I find your question interesting I'll give you karma. If you find my input useful please give me karma (I need it)


johnerrington

OK Karthyk, you know best. I'm out.

To select 1 Led from an xy grid requires x & y selectors.
To select 1 LED from an xyz cube requires x,y,z selectors.
in the schematic X is (say)D0-D8; from J1; Y is from J1 via a 3-8 decoder, enabling 1 led driver.    Z iS from J2;

That is why you have 8 leds lighting up. Or you should have.
I'm trying to help. If I find your question interesting I'll give you karma. If you find my input useful please give me karma (I need it)

karthyk

OK Karthyk, you know best. I'm out.

To select 1 Led from an xy grid requires x & y selectors.
To select 1 LED from an xyz cube requires x,y,z selectors.
in the schematic X is (say)D0-D8; from J1; Y is from J1 via a 3-8 decoder, enabling 1 led driver.    Z iS from J2;

That is why you have 8 leds lighting up. Or you should have.

Ok i am sorry dude you are right I will upload the pictures maybe you will understand help a brotha out man we don't need to fight I need your help





wvmarle

Bumping won't do you any good if you don't supply the information needed for an informative answer.

Don't know what information we need? Well, let's put it simple: whatever is needed to recreate exactly what you did.
Quality of answers is related to the quality of questions. Good questions will get good answers. Useless answers are a sign of a poor question.

PerryBebbington

If you have random LEDs lighting then you have made mistakes in your wiring. You need to check every LED very carefully and make sure it is correctly wired. The mistakes are there, you need to find them. You have the cube, we don't, however difficult this is for you it's a great deal harder for us, especially with incomplete information.

karthyk

#12
Jan 15, 2021, 08:43 am Last Edit: Jan 15, 2021, 08:44 am by karthyk
I tested out some of the leds with a multimeter, the anode and cathode are connected?!? What?!?
Is it because of faulty leds or heat damage due to bad soldering job?

wvmarle

Maybe you had the multimeter leads touching each other, or the wrong way around. Seriously, how would we know? I for one have yet to destroy an LED by simply soldering it. The things seem to be pretty robust.

Did you remember to test the LEDs before you put them in the cube?
Quality of answers is related to the quality of questions. Good questions will get good answers. Useless answers are a sign of a poor question.

TomGeorge

Hi, 
Welcome to the forum.

Please read http://forum.arduino.cc/index.php/topic,148850.0.html

Please attach your image files, the forum editor will automatically insert them into your post.

When testing with 5V on anodes and cathodes, did you use a current limit resistor?

Thanks.. Tom.... :)
Everything runs on smoke, let the smoke out, it stops running....

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