[PD] HID and timestamp

etienne deleflie et at lalila.net
Sat Aug 27 07:50:19 CEST 2005


I'm getting stuttering data output from my wacom tablet using the latest 

stuttering .... I put a [timer] on the output of the abs X position 
messages, and discovered that the HID object spits out around 4 X 
position messages in one go ..... i.e. without any time delay.

I've got a patch where you can really hear this (it is using a vd~ to do 
a dopler effect on ambisonic spatialisation stuff).... if I do a 
straight consistent line on my Wacom, the output comes out all stuttery 
and spitty.... and I have traced the reason to the fact that (around) 4 
messages get spat out at once. NOTE: changeing the poll value of the HID 
object does not aleviate the problem.

I concluded that this is what the timestamp (inlcuded in the USB 
messages) is for.... right? .......... the USB driver _or_ the USB 
device( I dont know about these things) instantaneously spits out 4 X 
positions and includes the timestamp between them.... so it should be 
(by using those timestamps) possible to get PureData to space out those 
4 messages in time and hence get a smooth data line.

do I sound like I dont know what I am talking about? does anyone want to 
educate me?


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