2 Teensy 3.2 boards

I have 2 Teensy boards, one is a 3.2 while the other is 3.? as it’s not marked with the version number. However it looks just like the 3.2 but with the markings. Coupled with these boards are 2 shields: SmartMatrix SD and SmartMatris Shield for Teensy 3.1. The problem that has developed is that one of my Teensy’s has stopped passing color info to the LED HUB75 panels. Every GIF image is only rendered in red color whereby alot of detail is missing. My questions are: 1. What combo shield/Teensy would I purchase to be able to continue the animated GIFs sketch? Of course there would have to be an SD card reader populated on the board. Is the Teensy 3.2 board out of production? What board replaces it?
Thank you very much,
Alfred Olivas

Hi Alfred, it sounds like you might have a power supply issue with one of your panels. Make sure you’re giving it a full 5V. Are you able to swap shields between the two panels to compare and help troubleshoot?

Red leds have a lower forward voltage than blue and green, so it’s common to see just some red pixels lighting up when’s there’s not enough power for all pixels

The best combo for playing GIFs is now a Teensy 3.5 or 3.6 with SmartLED Shield for Teensy 3. Or a Teensy 4.1 with SmartLED Shield for Teensy 4. I don’t make a shield with SD slot anymore as you can get Teensys with the slot. With a Teensy 3.2 you can always add a SD card external to the shield using the breakout pins on the shield and an external reader

Unfortunately, Teensy 3.2, 3.5, and 3.6’s are nearly impossible to find. Paul Stoffregen (creator of the Teensy) has said that a limited number of Teensy 3.5’s are in production right now, but they are likely to sell out. Beyond that, the chips used in Teensy 3.2, 3.5, and 3.6 are likely to unavailable for most of 2023.

At the moment, Teensy 4.0’s are sold out, but a new shipment is expected to to ship in December.

The Teensy 4.1’s are currently available (sometimes with the original ethernet interface, sometimes not). Given the Teensy 4.1 has a built-in SD card, you likely will want to use the Teensy 4.1 any way. You need to change the pin the SD card is on to ‘BUILTIN_SD_CARD’. Using the Teensy 4.0 shield, the Teensy 4.1 will work fine (I have one displaying animated 64x64 GIFs right now). Note, if you attach the Teensy 4.1 to the shield, and then attach that to the display, you will need to remove some of the pins past the first 14 pins due to dimensions of the board.

The Teensy 4.0/4.1 PixelMatrix shield has a completely different pinout from the current 3.5/3.6 shield. I don’t have the original SmartMatrix 3.2 shield, so I don’t know what the pinout was for the original shield, but I assume that would also be different than the Teensy 4.0/4.1 shield.

I haven’t played around with it for the PixelMatrix shield, but the lastest version of Teensyduino (1.57) has support for using the extra flash memory of the Teensy 4.0/4.1 as a file system that you can read from. But the space is fairly small (total flash size for Teensy 4.0 is 2 megabytes, and 8 megabytes for Teensy 4.1 and you need to hold the program and such in flash).

The Teensy 4.1 also has two sets of solder pads underneath the Teensy that you can solder 1 flash chip and one PSram chip (or 2 PSram chips if you need more volatile memory).

If your soldering skills are good, the Teensy 4.0 does have a set of solder pads underneath the Teensy 4.0 that you can connect a SD card reader. This can be faster than using an external SD card reader. But with the Teensy 4.1, you don’t have to do that.

But in general, it is simpler to just use the SD card on the Teensy 4.1.

A post was split to a new topic: RP2040 HUB75 DMA Driver

Thank you for the helpful info. Yes, the global chip shortage is affecting my creativity.

for what it’s worth, if you don’t mind doing a little bit of wiring (no shield), ESP32 also works fine for sizes below 128x64