32x32 LED Matrix Hardware Issue

EL Wire/Tape/Panels, LEDs, pixels and strips, LCDs and TFTs, etc products from Adafruit

Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.
User avatar
Brycek
 
Posts: 15
Joined: Sat Sep 27, 2014 3:36 pm

32x32 LED Matrix Hardware Issue

Post by Brycek »

Hello,

I recently bought a Medium 32x32 LED Matrix from the store, along with a SmartMatrix, and a Teensy 3.1. I loaded the example code, and tried to use it, and when I powered it on for the first time, all I got was random flickering pixels in random colors. I determined it was not the smart matrix by completely unplugging it, and only pushing power to the board, still got flickering. In the past, power only would result in a blank display. Has anyone else had this issue? Do I need to return this one?

Some of the patterns for those interested (you can actually see the LEDs in the lens flare):
Photo on 10-1-14 at 9.00 PM #2.jpg
Photo on 10-1-14 at 9.00 PM #2.jpg (107.34 KiB) Viewed 872 times
Photo on 10-1-14 at 9.02 PM.jpg
Photo on 10-1-14 at 9.02 PM.jpg (138.43 KiB) Viewed 872 times

Thanks!
B_man
Last edited by Brycek on Sat Nov 01, 2014 9:20 pm, edited 1 time in total.

User avatar
Franklin97355
 
Posts: 23912
Joined: Mon Apr 21, 2008 2:33 pm

Re: 32x32 LED Matrix Hardware Issue

Post by Franklin97355 »

Could you post clear pictures of both sides of your board showing any soldering you have done and the connections to it?

User avatar
Brycek
 
Posts: 15
Joined: Sat Sep 27, 2014 3:36 pm

Re: 32x32 LED Matrix Hardware Issue

Post by Brycek »

I have not soldered anything to the matrix, mine came with the 4 pin power connector.

here is my teensy,
IMG_1205.JPG
IMG_1205.JPG (377.96 KiB) Viewed 849 times
IMG_1201.JPG
IMG_1201.JPG (248.63 KiB) Viewed 849 times
cont. below |
\/

User avatar
Brycek
 
Posts: 15
Joined: Sat Sep 27, 2014 3:36 pm

Re: 32x32 LED Matrix Hardware Issue

Post by Brycek »

And here's my smart matrix,
IMG_1212.JPG
IMG_1212.JPG (340.82 KiB) Viewed 849 times
IMG_1213.JPG
IMG_1213.JPG (389.37 KiB) Viewed 849 times

User avatar
adafruit2
 
Posts: 22148
Joined: Fri Mar 11, 2005 7:36 pm

Re: 32x32 LED Matrix Hardware Issue

Post by adafruit2 »

its worth checking, are you sure the smartmatrix shield is plugged into the LED board right? its easy to be 'off by one'
what code are you running on the teensy?

User avatar
Pixelmatix
 
Posts: 17
Joined: Wed Sep 24, 2014 3:50 pm

Re: 32x32 LED Matrix Hardware Issue

Post by Pixelmatix »

I don't see any soldering errors. My suggestion is also to check for the female header being off by one when plugged into the panel.

User avatar
Brycek
 
Posts: 15
Joined: Sat Sep 27, 2014 3:36 pm

Re: 32x32 LED Matrix Hardware Issue

Post by Brycek »

If it is was off by one, would that have fried it? It's not offset now, but I have unplugged and replugged it a few times.

edit: I am using the "FeatureDemo" for the smartmatrix

User avatar
Pixelmatix
 
Posts: 17
Joined: Wed Sep 24, 2014 3:50 pm

Re: 32x32 LED Matrix Hardware Issue

Post by Pixelmatix »

I've been off by one a couple times, and I've never damaged a panel.

Is the Teensy Loader application that loads the compiled sketch onto the Teensy working properly? Does it show a progress bar and that programming was successful?

User avatar
Pixelmatix
 
Posts: 17
Joined: Wed Sep 24, 2014 3:50 pm

Re: 32x32 LED Matrix Hardware Issue

Post by Pixelmatix »

Let's rule out that it's a compiler or firmware configuration issue.

You can program this .hex file with the Teensy Loader program. If it's working it will cycle between two bitmaps on the display. It will also blink the LED on the Teensy, alternating every second. Let me know if it's displaying properly, and if not, let me know if the LED on the Teensy is blinking. If it's not blinking when plugged into the SmartMatrix Shield, try running the Teensy on its own.
Attachments

[The extension hex has been deactivated and can no longer be displayed.]


User avatar
Brycek
 
Posts: 15
Joined: Sat Sep 27, 2014 3:36 pm

Re: 32x32 LED Matrix Hardware Issue

Post by Brycek »

OK. That's working fine. I guess it was code. Also note, that the code doesn't run properly when the Teensy is disconnected from the smartmatrix.

I'm going to let it run for a while, and see how it goes. Thanks!

User avatar
Pixelmatix
 
Posts: 17
Joined: Wed Sep 24, 2014 3:50 pm

Re: 32x32 LED Matrix Hardware Issue

Post by Pixelmatix »

Did you cut the VUSB trace on the Teensy as part of the install? That's probably why the code isn't running when disconnected from the SmartMatrix Shield: the Teensy won't be getting any power when disconnected from the shield.

It could be a issues with the Teensy settings, here's the settings you need:
https://learn.adafruit.com/smartmatrix- ... ino-sketch

User avatar
Brycek
 
Posts: 15
Joined: Sat Sep 27, 2014 3:36 pm

Re: 32x32 LED Matrix Hardware Issue

Post by Brycek »

I was confused with the power instructions on the smart matrix website, and now I have a connected VUSB, and no diode on the smartmatrix. Right now, I am powering both the teensy, and the smart matrix separately. See my video below for info.

https://www.youtube.com/watch?v=0CrFv06 ... _SNHcsyP8w

User avatar
Pixelmatix
 
Posts: 17
Joined: Wed Sep 24, 2014 3:50 pm

Re: 32x32 LED Matrix Hardware Issue

Post by Pixelmatix »

The random two lines symptom comes from the code on the Teensy crashing, the GPIO driving the display are left floating after the code crashes. If you're using backBuffer and write outside of the buffer you could overwrite some other variables and crash the code. Try a simpler sketch that uses some simple functions like fillScreen() and scrollText() and see if that works.

I don't think you damaged anything by using both the diode and VUSB.

If you want to just use the barrel connector you cut the VUSB trace and add the diode.

User avatar
Brycek
 
Posts: 15
Joined: Sat Sep 27, 2014 3:36 pm

Re: 32x32 LED Matrix Hardware Issue

Post by Brycek »

*facepalm* I just realized I was running at 16 MHz!

No more crashes now, working great. The last thing I need is the spec of that diode, I kinda killed mine. :( Thanks a bunch!

User avatar
Pixelmatix
 
Posts: 17
Joined: Wed Sep 24, 2014 3:50 pm

Re: 32x32 LED Matrix Hardware Issue

Post by Pixelmatix »

Great! I'm glad it's working now.

It's a common 1N4001 diode. Should be easy to replace.

Locked
Please be positive and constructive with your questions and comments.

Return to “Glowy things (LCD, LED, TFT, EL) purchased at Adafruit”