allow easy configuration of single or double tapping

[ladyada]

see below!

import time
from adafruit_circuitplayground.express import cpx

# Set up the accelerometer to detect tapping ('click')
cpx.detect_taps = 1

while True:
    if cpx.tapped:     # Look for a single tap
        print("Tapped", time.monotonic())
    time.sleep(0.01)

[kattni]

My concern is the sensitivity with single-tap. Same issue in the first demo example you sent me, I can't touch the board without setting it off. The threshold, time_limit and time_latency values for double-tap are apparently wrong for single-tap. I've linked an example of a way to address this issue.

Is there a reason why you decided to do detect_taps and tapped vs. single_tap and double_tap? I wrote up the code to have single and double separate, and tested it. In that version, I am able to tweak the set_tapvalues separately. It will take more testing to get it right, but here is what it looks like initially: https://github.com/kattni/Adafruit_CircuitPython_CircuitPlayground/blob/single-double-tap/adafruit_circuitplayground/express.py

My issue with having both single and double available are the same as before, that you can use single- and double-tap together (regardless of implementation type), and it returns mostly singletap. Seems like something we'd have to address in documentation or a guide so people aren't frustrated trying to use double-tap and single-tap together.

[kattni]

Why is detect_taps included twice?

[ladyada]

one is the setter (detect_taps) and one is the variable that is set by the setter (_detect_taps)

[kattni]

Ah thank you!

[kattni]

These numbers work for double-tapping, but it seems like they are not great for single-tap. Did you have issues with sensitivity? I can't touch the board without setting single-tap off.

[ladyada]

we can tweak it for single/double, maybe set threshhold to 24 or so for single!

[kattni]

I had to set single-tap threshold to 70 with them separated before single-tap wasn't going off constantly. I'll test some numbers and get back to you.

[ladyada]

sure sounds good, yeah with 8G its hard to get good numbers!

[kattni]

It looks like 80 is a good threshold.

When you said "tweak it for single/double" were you saying tweak the number in this implementation or did you want me to clean up the single_tap/double_tap implementation I linked?

[ladyada]

yah i mean checking if you want 1 or 2 at this line
3a0c653
and then changing what you call self._lis3dh.set_tap with. i can commit late tonite when i get home, or you can take a go :)

[kattni]

I'm still curious though, why detect_taps and tapped, rather than single_tap and double_tap?

[kattni]

I'll commit it after the weekly :)

[ladyada]

zoOOOOOoooM!

i think given you have to set up the filter differently, maybe less difficult to just say "hey you get single or double, your choice"?

[kattni]

It doesn't look much different on the code end. The library sets everything up and the code is basically:

if cpx.double_tap:
    blah
elif cpx.single_tap:
    etc

Even with detect_taps and tapped, you can do both, and it looks more like this:

cpx.detect_taps = 2
if cpx.tapped:
    blah
cpx.detect_taps = 1
if cpx.tapped:
    etc

Either way, double doesn't really work with single.

So sticking with this: Do we want to try to put in something that makes it fail if you try to use it twice? Or deal with it in documentation? Or something different?

(I had an issue with LIS3DH and 2 instances, but fixed that, it does work with set_tap twice in a while loop.)

[kattni]

I'd like to do some work on the documentation for these changes, update the explanations and add another example where you can delay between checking for single and double taps.

I went straight to trying to use both in a tight loop, so I assume others might too. So I thought if we explain more clearly that it's single OR double, and also have an example of being able to use both with a delay between checking for single and double, that we'll catch that well enough.

I'll merge this one and do another PR for the changes so I can work on them locally. Let me know if this works!

[kattni]

I'm going to merge this PR and do the next set of updates locally.