Teensy 3.1 + SPI TFT LCD

Hello everyone, I was wondering if 1-2 Teensy 3.1 would be able to run 2 different 128x160 SPI TFT LCD screens (link below). If 1 Teensy could run both that would be great but I am prepared to have a separate Teensy for each LCD. The goal of this project is to have VU meters and/or some kind of visualizer embedded in a pair of headphones and have each screen be synced to the R/L channels respectively. The LCD should only use 4 connections and then 1 connection for a mono channel audio signal. I have worked with Auduinos before but I have never tried using LCDs in any of my projects. I want to make sure my setup will function correctly. Any advise you have on this project would be greatly appreciated.

LCD Screens - http://www.adafruit.com/products/358

At a minimum, you could use a single SPI port's bits wired to both LCDs, and two CS (chip select) bits.
There are more elaborate approaches, but the above is commonly done

Would a single Teensy 3.1 be capable of running both without getting caught up? It would also have to do the computations for the equalizer and vu meters. I'm not sure how much actual computation this might all take and if the Teensy would be able to handle it all in "real-time". If you think that a single Teensy could do it, then I might just get one for now and do the testing and if it needs a bit more I can get another Teensy later.

Teensy would do each one in succession (per your code).

Yes, I believe this will work. This display has a high optimized library for Teensy3.

https://github.com/PaulStoffregen/Adafruit_ST7735

Each display needs 5 signals: cs, rs, sid, clk and rst.

Connect both display's clk to pin 13, and both sid to pin 11.

You might be able to share rs, but each display will definitely need its own cs. Each should have its own rst.

To use the optimized mode, you must connect cs and rs to certain pins on Teensy 3.1: 2, 6, 9, 10, 15, 20, 21, 22, 23. Only those pins work for the cs and rs signals in the high speed mode.

Also, certain pairs must NOT be used:

2 & 10
6 & 9
20 & 23
21 & 22

For example, you might connect cs and rs to pins 2 and 6 on the first LCD, and cs & rs to pins 20 & 21 on the other LCD.

Any digital pins can be used for the rst signals.

Would a single Teensy 3.1 be capable of running both without getting caught up?

Click to expand...

Well, that depends on how you write your code. Using 32 bit integers is the best way. Teensy 3.1 is fast, but of course if you write extremely slow code or use a lot of floating point math, it will only be able to run the code you write.

Using that optimized library will help a lot. It's dramatically faster than using these displays on any other board.

There are 8 and 16 bit parallel interface TFT displays, which are faster than serial, but a lot of wires are needed.