[PD-dev] comport profiling, switching default poll time to 10ms

[Roman Haefeli]

Hi Hans

On Wed, 2012-03-07 at 13:06 -0500, Hans-Christoph Steiner wrote:
> I was doing some comport profiling using an Arduino and Firmata.  I
> noticed that at the default poll time of 1ms, that there were many
> fruitless calls to comport_tick() before any bytes where read. And
> that the bytes are always read and written in clusters, no matter the
> poll time.  

I think your numbers clearly suggest that lowering the polling rate does
no harm. I didn't do any serious testing, but I couldn't detect any
additional jitter due to this change. And since the polling time can be
adjusted with a message, I'd say it makes sense to leave the optimized
10ms as the default.

As a quick test, I toggled on and off the LED 13 on the arduino board
with a [metro 8]. By manually weaving the board as quickly as possible,
I could something like the following pattern drawn by the LED:

####   ######     ######    #####     #####     ######     ######

and this pattern didn't change noticeably when switching between 1ms and
10ms polling time.

Roman