Figure out: How to configure screen brightness.

[Asmageddon]

Currently, when turned on, the device often sets screen and knob LEDs so bright as to illuminate the whole room, which isn't conductive to falling asleep. Being able to set the values lower, or add more steps based on light sensor(I think there is one) would be really nice.

[m-kozlowski]

there is one.
0x20009d74 and 0x20009d78 are ALS raw and hysterysis values.

I wouldn't trust it too much, but I think there's something like that:

name	addr	type
PWM_SetBrightness	0808044c	Function
PWM_SetBrightnessAlt	08080458	Function
BrightnessLevelToPWM	08080470	Function
pwm_brightness_curve	0808057c	Data Label

[m-kozlowski]

Backlight logic sits inside FUN_0807a1d0
var 0xfb is current als reading (#ASR)
var 0xfc is averaged value (#ASF)
var 0xfd is threshold (can be get/set with resmed_config.py set ATH)

logic here is (if i get it right)

if fc < fd:
    allow dimming

if fc > scale(fd):
    start 3 second timer
    if still bright after 3 seconds:
        exit dim state

FUN_0807a4ac is smoothing filter
FUN_0807a4d2 is filtered float to int

[m-kozlowski]

var_id	var_name	default	desc
0x0FE	LBL	50	button backlight low level
0x100	LBH	100	button backlight high level
0x0FF	LLL	60	lcd backlight low level
0x101	LLH	100	lcd backlight high level
--------	------------	---------	------
0x0FB	ASR	4095	ambient sensor raw reading
0x0FC	ASF	4095	ambient sensor filtered reading
0x0FD	ATH	15	bright/dark threshold