Button Box with Leonardo 5 Rotary Encoders is it possible.

Projects General Guidance
1

Hi Guys,

I am currently designing a button box, and as all projects research is needed.

I have never used a rotary encoder, but have looked into how to use and code.

Hopefully mine will arrive shortly for me to play....

This question is using a Leonardo is it possible to use 5 encoders (non polling.)

I see that the Leonardo has 5 External Interrupts as shown Reference/AttachInterrupt

I also understand that to use the encoder will need at least 2 interrupts per encoder.

However i have read that it may be possible to use a single external interupt pin and a (a)nother pin non interupt for the other output for the encoder ?? but cannot find the article i read a month ago.. >:(

Leonardo Pin Layout

Also it would seem that the 5th External Interrupt ( pin 7.) will need some code adjustment ..

External Interupts 5th Pin Adjustment Code

If you have any possible any suggestion or code suggestions welcome.

Thanks

Neil

2

Why not simply use polling?

3

By polling is there not a chance that i will miss a pulse change of the encoder ?

if polling method is an option, can i connect 5 encoders ?

Thanks

Neil

4

Calculate yourself how many pulses will arrive per second, when the encoders move at maximum speed (driven how?).

AFAIR (pin change) interrupt handling is limited to about 100kHz in software - please correct me if I'm wrong. Polling a port for 8 signals at once could be faster.