Is the smart matrix shield required for a teensy 3.5?

Hi there, and big thanks to you guys =)

I’ve wired up a teensy 3.5 without a shield to 4 x 64 * 32 panels, but I’m getting some unwanted image distortion ( the image kinda blurs off to the side). Is this due to the absence of 5V level shifters? . longer ribbon cables and more screens seem to increase the distortion.

If I add in some level shifters would that sort this out? Are other elements of the smart matrix shield also required?

Any help would be appreciated. Thanks.

Level shifters are the first thing I’d try. The Teensy 3.5 is outputting 3.3V, which isn’t enough for some panels.

ahhh, thanks for pointing this out. I thought the teensy was 5V logic, but it’s not. I believe it’s 5V tolerant, which isn’t the same thing.

Thanks

Just to note, some Teensy’s aren’t even 5V tolerant!

  • All ARM Teensys use 3.3 volts as their native voltage. Some Teensys (LC, 3.0, 3.6, 4.0, and 4.1) can be damaged if they get more than 3.3 volts on any pin, while other Teensys (3.1, 3.2, and 3.5) will tolerate 5 volt input for the digital pins (the analog only pins and the reset, program pins cannot tolerate anything more than 3.3 volts). To be compatible, no Teensy pin except for VIN and VUSB must ever get more than 3.3 volts;

can you explain, what’s the purpose of the 74374PW chip? is it required? or would just using a 74245PW to level shift all pins for the panel suffice?

any info would be much appreciated

There’s details here:

The 74374 chip is the “improved circuit” mentioned