1*4882a593Smuzhiyun* Pattern format for LED pattern trigger 2*4882a593Smuzhiyun 3*4882a593SmuzhiyunThe pattern is given by a series of tuples, of brightness and duration (ms). 4*4882a593SmuzhiyunThe LED is expected to traverse the series and each brightness value for the 5*4882a593Smuzhiyunspecified duration. Duration of 0 means brightness should immediately change to 6*4882a593Smuzhiyunnew value, and writing malformed pattern deactivates any active one. 7*4882a593Smuzhiyun 8*4882a593Smuzhiyun1. For gradual dimming, the dimming interval now is set as 50 milliseconds. So 9*4882a593Smuzhiyunthe tuple with duration less than dimming interval (50ms) is treated as a step 10*4882a593Smuzhiyunchange of brightness, i.e. the subsequent brightness will be applied without 11*4882a593Smuzhiyunadding intervening dimming intervals. 12*4882a593Smuzhiyun 13*4882a593SmuzhiyunThe gradual dimming format of the software pattern values should be: 14*4882a593Smuzhiyun"brightness_1 duration_1 brightness_2 duration_2 brightness_3 duration_3 ...". 15*4882a593SmuzhiyunFor example (using sysfs interface): 16*4882a593Smuzhiyun 17*4882a593Smuzhiyunecho 0 1000 255 2000 > pattern 18*4882a593Smuzhiyun 19*4882a593SmuzhiyunIt will make the LED go gradually from zero-intensity to max (255) intensity in 20*4882a593Smuzhiyun1000 milliseconds, then back to zero intensity in 2000 milliseconds: 21*4882a593Smuzhiyun 22*4882a593SmuzhiyunLED brightness 23*4882a593Smuzhiyun ^ 24*4882a593Smuzhiyun255-| / \ / \ / 25*4882a593Smuzhiyun | / \ / \ / 26*4882a593Smuzhiyun | / \ / \ / 27*4882a593Smuzhiyun | / \ / \ / 28*4882a593Smuzhiyun 0-| / \/ \/ 29*4882a593Smuzhiyun +---0----1----2----3----4----5----6------------> time (s) 30*4882a593Smuzhiyun 31*4882a593Smuzhiyun2. To make the LED go instantly from one brightness value to another, we should 32*4882a593Smuzhiyunuse zero-time lengths (the brightness must be same as the previous tuple's). So 33*4882a593Smuzhiyunthe format should be: "brightness_1 duration_1 brightness_1 0 brightness_2 34*4882a593Smuzhiyunduration_2 brightness_2 0 ...". 35*4882a593SmuzhiyunFor example (using sysfs interface): 36*4882a593Smuzhiyun 37*4882a593Smuzhiyunecho 0 1000 0 0 255 2000 255 0 > pattern 38*4882a593Smuzhiyun 39*4882a593SmuzhiyunIt will make the LED stay off for one second, then stay at max brightness for 40*4882a593Smuzhiyuntwo seconds: 41*4882a593Smuzhiyun 42*4882a593SmuzhiyunLED brightness 43*4882a593Smuzhiyun ^ 44*4882a593Smuzhiyun255-| +---------+ +---------+ 45*4882a593Smuzhiyun | | | | | 46*4882a593Smuzhiyun | | | | | 47*4882a593Smuzhiyun | | | | | 48*4882a593Smuzhiyun 0-| -----+ +----+ +---- 49*4882a593Smuzhiyun +---0----1----2----3----4----5----6------------> time (s) 50