Talk:OMAP vibration device
From WebOS Internals
My own research has offered certain different results than are identified in this article, and others which are not mentioned:
First, as of 220.127.116.11 the low threshold for perceptible vibration, whether charging or on battery power, is nearer to 17%, not 20% as stated.
Second, default duty_cycle is 99, not 50, and can be demonstrated through the following methods:
(assuming duty_cycle has been set to a value other than default)
a.) cycle the ringer switch from vibe to ring and back (or just set to vibe if already on ring)
b.) open/adjust ringer volume via Sounds and Ringtones application
c.) Luna restart
d.) Java Services Restart
e.) Any system initiated event (as in receiving a text message or inbound call - any event calling for an alert)
e.) Device restart
Essentially, any event not engaged through terminal command.
Each action will affect a duty_cycle value reset to the default 99.
Such evidence leads me to conclude that duty_cycle manipulation via echo interface functions as a conditional on/off switch rather than a permanent data point and is of little practical value otherwise. However, in observation of the proclivity for webOS to retain a default duty_cycle value under a multitude of varying conditions, one might speculate that a singular data point of a more permanent nature exists. Further research toward the end of charge conservation via work load reduction at the vibration device node appears warranted.