• 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 Matthias Schneider - 2009-06-03
Last edited by Rafaël Carré - 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  Rafaël Carré
2009-06-07 23:33
Reason for closing:  Accepted
Thomas Martitz commented on 2009-06-03 17:41

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.

Rafaël Carré commented on 2009-06-03 18:59

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

Rafaël Carré commented on 2009-06-04 11:43

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()

Matthias Schneider commented on 2009-06-04 18:59

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.

Bertrik Sikken commented on 2009-06-04 19:05

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.

Bertrik Sikken commented on 2009-06-04 20:08

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.

Matthias Schneider commented on 2009-06-05 17:37

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

Hilton Shumway commented on 2009-06-05 17:39

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?

Rafaël Carré commented on 2009-06-05 17:46

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

Rafaël Carré commented on 2009-06-06 13:56

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)
Rafaël Carré commented on 2009-06-07 23:28

no effect on Clip not needing the patch


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