40 lines
1.1 KiB
Markdown
40 lines
1.1 KiB
Markdown
|
I did some performance testing.
|
||
|
|
|
||
|
|
The Pro Micro runs an Atmel 32u4 at 8MHz.
|
||
|
|
If the code does nothing else,
|
||
|
|
I was able to poll all pins around 13 times every 1ms,
|
||
|
|
or 13kHz.
|
||
|
|
|
||
|
|
|
||
|
|
Sample Rate
|
||
|
|
-----------
|
||
|
|
|
||
|
|
The number of samples taken since the last HID report
|
||
|
|
is sent as the second Y axis.
|
||
|
|
If you use the
|
||
|
|
[included gamepad tester](gamepad.html),
|
||
|
|
it will show the approximate number of samples as an integer,
|
||
|
|
for Y axis 2.
|
||
|
|
|
||
|
|
This is approximate,
|
||
|
|
because the browser encodes the value as a real number between -1 and 1.
|
||
|
|
We convert it back, but may lose a little precision.
|
||
|
|
It's close enough for me,
|
||
|
|
hopefully it's close enough for you.
|
||
|
|
|
||
|
|
|
||
|
|
Debouncing
|
||
|
|
----------
|
||
|
|
|
||
|
|
Using `millis()` time to debounce the switch
|
||
|
|
roughly halved my sample frequency.
|
||
|
|
So instead, I do some preprocessor arithmetic
|
||
|
|
to calculate how many samples to take after an edge,
|
||
|
|
in order to debounce switches.
|
||
|
|
|
||
|
|
The drum controller was a partcular pain:
|
||
|
|
in addition to the switch bouncing,
|
||
|
|
the stick was bouncing on the rubber pad.
|
||
|
|
I settled on a 40ms silence window as feeling pretty good.
|
||
|
|
You can adjust this if you want to.
|