Method for QuickStart touch pads

Addington

I would like to have a general method for using the QuickStart touch pads as switches. Although the touch pads are unreliable, they are on the board, and it would be nice to use them despite their limitations. I am trying to adapt Ariba's 2011 version of TouchPad.spin, but have failed so far. Any clues would be much appreciated.

Please find attached my test harness.

DigitalBob

You need the Touch button object

DigitalBob

Like this

DigitalBob

And this

Duane Degn

I seems like there are lots of variations on touch pad objects. I think part of the reason there's so many different versions is the touch pads will behave differently in different weather and different skin types. People modify the driver to work best for their climate and their skin.

Here's my attempt to explain how to use the touch pads as buttons.

I used the touch pads as inputs in my Quickstart Servo tester.

Here's a thread with some Quickstart projects listed.

Addington

Many thanks Digital Bob for pointing me towards "Touch Buttons" and the LED demo application. I have just started to play with it. It works.

Thank you Duane Degn for posting all that material. Just had a quick look. Fantastic. Especially the bits that apply to robots. A lot to study.

Well...time to get stuck in....

Addington

I just followed Duane Degn's recommendations with success. What follows is a simple test harness.

CON
  _clkmode = xtal1 + pll16x
  _xinfreq = 5_000_000

VAR
  long delay          'Time to measure discharge
  byte button[8]      'For storing state of touch pads

OBJ
  Buttons : "TouchButtons111029a"       'Object that does the heavy lifting

PUB Main
  delay := clkfreq/100                  'Optimal value depends on humidity, etc.
  Buttons.Start(@delay, @button)
  waitcnt(clkfreq/1000 + cnt)           'Time for cog to be launched

  dira[23]~~                            'Leftmost LED, can be any other LED
  repeat
    if button[2] == 1                   'Third pad from the right, can be any other pad
      outa[23]~~
      waitcnt(clkfreq/4 + cnt)          'Time to see the LED
    else
      outa[23]~
      waitcnt(clkfreq/4 + cnt)

The links are really interesting. A lot to learn.

Duane Degn

Thanks for making the demo program. I added a link back you your post from the other thread.

I hope you share photos and video of your projects with us.

Tracy Allen

Check out this old thread too, alternative-mode-for-the-quickstart-touch-buttons.

Addington

Many thanks Tracy Allen.

Gosh! Who would have thought that supposedly simple touch pads would be the subject of such a lot scrutiny and experimentation.

Today, another touch pad thread has popped up in the forum.