LED&Key and stepper motor

[DaveX]

@kmanuele

I've been playing with the LED&Key module as a possible stepper RPM display.

The fastest library I've found for this is Tom Almy's TM1638 SPI lib.

Is this the LED&KEY module:

TM1638 8-Bit Button Digital LED- Seven Segment Display Module

and this the library?

TM1638 and SPI Interrupts

This is a follow up on my previous re: Tom Almy's TM1638 library. I've attached his code, and I replaced his test loop() code (which works) with a simple test that should cycle the indicated LED's on and off. However, it doesn't work. After the second updateDisplay(), the LEDs are never turned off. Strangely, if I insert a Serial.println(), it works as expected. I don't understand the indexing in his ISR(), which is where I think the problem lies. Anybody willing to investigate ? Thanks /* …