• Status Closed
  • Percent Complete
  • Task Type Patches
  • Category LCD
  • Assigned To No-one
  • Operating System All players
  • Severity Low
  • Priority Very Low
  • Reported Version Version 3.2
  • Due in Version Undecided
  • Due Date Undecided
  • Votes
  • Private
Attached to Project: Rockbox
Opened by matsch - 2009-06-03
Last edited by funman - 2009-06-07

FS#10273 - Enable OLED-Screen for Clip v1 (without FM chip?)

Patch enables OLED-Screen for some Clip v1 which are different from
others (due to missing FM chip?). The DC-DC converter of AS3525 is
switched on. Parameter x of ascodec_write(AS3514_DCDC15, x) has no influence on screen contrast unless x = 0.

Closed by  funman
2009-06-07 23:33
Reason for closing:  Accepted

I think that should be toggled in backlight_on() and backlight_off() (or lcd_enable(), that’s the same on the clip anyway). The DCDC doesn’t need to be on without backlight.

I hesitate if we should cache radio_hardware_present() value and use it to enable/disable DCDC.

We would need to have at least one report of a Clip without a FM chip and with a display working without this patch

According to bertrik, the power consumption is small enough to enable powering unconditionally, so the patch should go in when it disables DCDC in lcd_enable()

I tried to toggle the DCDC in lcd_enable. For a short time I see a bright screen when ascodec_write(..) is in lcd_init-device
like in the patch, but then the screen is black. If ascodec_write(..) is not in lcd_init_device the screen is black from start.

My reasoning is that the current battery life time is about 7 hours for a 350 mAh battery, so it’s drawing about 50 mA on average.
For clips that don’t need the DCDC15, I don’t expect the 1.25 mA current to really run into anything. Even if it does, it’s only 1.25/50 = 2.5% more current draw.

This is roughly what the OF does: enable DCDC15 just before enabling the display and disable it again after disabling it. The OF uses a small delay between enabling DCDC15 and enabling the display, possibly to avoid visual glitches.

I can confirm that the patch works with my clip.
I ran battery_bench wit 7h30 running time.

Can somebody with a Clip that doesn’t need this patch run battery benches with it applied and without and post them to compare the difference?

i’ll run the benchmarks and post the results this week end

here are some results, but I had a problem : playback stopped itself while testing SVN so results might not be 100% reliable

EDIT: WRONG TEST : the LCD was off during both benches .. I feel stupid .. I’ll retest again.

   clip.png (4.5 KiB)

no effect on Clip not needing the patch


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