Issues with Teensy+Shield+RGB panel over time


We setup a GIF wall at our museum using the SmartMatrix Animated GIF Player tutorial.

There are 16 individual panels each with:

  • Teensy 3.1
  • SmartMatrix Shield (the older one)
  • 32x32 RGB LED panel
  • Groups of 4 panels have their power wired in series to one power supply.

The wall has been installed for over a year and we have had minor issues in that time, mostly with MicroSD cards corrupting (an easy fix). Recently we have had more significant issues that are puzzling.


  • GIFs will freeze after a few hours. A power cycle fixes this.
  • We have a few panels that will not display GIFs, either immediately after power-on, or after a few hours.There is no error message, just a blank screen. Other panels with the same GIFs will be displaying correctly.


  • Why would a panel suddenly stop displaying GIFs?
  • Is there an issue with the GIFs that would cause them to freeze at a random point?
  • Has anyone else had similar issues with setups that are running 24/7?



I’m sorry to hear about these issues. It’s hard to know what could be causing the lockups after a few hours. If I had to guess, it might be from getting unexpected behavior or data from the SD card, which the SD card or GIF decoder library can’t handle. There are some stability improvements in SmartMatrix 3.0, the latest release, which might be worth switching to if you are able.

Are you able to hook up a USB cable to one of the units that won’t play GIFs at all? The Teensy is outputting debug information over USB-Serial while running the AnimatedGIFs program. That could help track it down.

What version of the SmartMatrix Shield are you using? Version 3 adds level shifting buffers on all the signals going to the panel for better compatibility with some panels that require 5V signals. It’s possible but unlikely that your panel requires 5V, but worked ok at 3.3V for a while and now doesn’t.

Are you able to swap the SmartMatrix Shield from one panel to another, to try to isolate the issue?


Some ideas for workarounds: You can enable a “watchdog timer” on the Teensy that will reset the CPU if the program doesn’t check in every so often. It’s not trivial to set up. That might help if the program was stuck somewhere in the GIF or SD code. One link:

If the program is running, and can recognize that something has gone wrong, it could force a reset. One link: