Scanning encoder debounce on new scope

[Demon]

Nice chip! I did not knew that one although I am of the CMOS era! ...

I also found the MAX6818 debouncer, but it's $4.37 for 8-bit at JLCPCB.

... since you master the art of software, I think is waste of money to add hardware when you can debounce in software. ...

More like master of none.

... One example. Read all buttons in an array. After a period of say 10ms, read again and compare all the buttons. One pass, reading and debouncing all buttons.

Ioannis

I might still go for that. But I'd really like to avoid any debounce on the PICs so they are free to USART with the main USB PIC.

[Ioannis]

I might still go for that. But I'd really like to avoid any debounce on the PICs so they are free to USART with the main USB PIC.

This can work just fine:

1. Set up a timer interrupt at 10ms. Or even at 1ms and after ten int's do step 2.

2. Every interrupt read the buttons into the arrays. You can use a low priority interrupt if the PIC supports it.

3. Either with or without interrupt use the hardware USART to communicate. If you choose interrupt driven USART, use it as high priority, or Disable as long as you do serial, the timer interrupt.

Problem solved.

Ioannis

[Demon]

I wanted to see just how sharp a Schmitt trigger could clean up a signal.

This is using a MR0102 with rocker actuator, followed by the Bourns RC debounce circuit, and then inverted with a TCC74HC14 Schmitt trigger, followed by LED/330R resistor:



(text on image has been corrected)


Datasheet says negative threshold is 1.6V at 4.5V. This is USB 5V, so 1.8-1.9V seems ok to me.

[Ioannis]

What a magic tool Oscilloscope is, right?

Ioannis

[Demon]

Darn tootin' right.

It's nice to finally use it as a diagnostic/testing tool. The scope has always been a mystery to me. I've always wanted to use one, but never had any electronics training. So it's slow; getting old and a worsening memory doesn't help, but help from you folk make it fun.

One thing is for sure, I wouldn't hire me to do this stuff.

[HenrikOlsson]

Your waveforms seem to indicate that you might benefit from adjusting the trimmer capacitor on your probe(s).

[Demon]

Your waveforms seem to indicate that you might benefit from adjusting the trimmer capacitor on your probe(s).

I noticed that "rhythmic pulse" too. I figured it might be the breadboard.

I wanted to enjoy my scope for a few days before tweaking it and messing it up.
😄