[Arm-netbook] need help interpreting AXP209 datasheet (LDO1SET->VINT)

[luke.leighton]

On Sat, Nov 10, 2012 at 6:38 PM, Henrik Nordström
<henrik at henriknordstrom.net> wrote:
> lör 2012-11-10 klockan 03:30 +0000 skrev luke.leighton:
>> http://rhombus-tech.net/community_ideas/kde_tablet/news/
>>
>> another update: i've discovered that the AXP209 is f*****g awesome.
>
> Yes, it's quite capable for being a PMU, and quite easy to work with.
>
>> it has a RTC battery output which can be connected to the STM32F's BAT
>> input, supplies 3.3v @ 30mA and this would keep the STM32F's internal
>> registers happily supplied, along with its RTC.
>
> Hmm. Usually you connect tjat to the A10 for powering it's RTC.
>
> Or are you using an AXP209 in the I/O board?

 *cackle*... yes :)

>> i'll have to waste a couple of pins on a 32mhz oscillator (shaaaame)
>> which, joking aside, might actually turn out to be a problem, there's
>> a bit of a shortage of pins, because i connected up an extra SD-Card
>> to the STM32F (yay!) in SPI mode (oops).
>
> What will the SD-card be used for?

 ohh, i don't know - it just seemed like too good an opportunity to miss :)

 it would mean that the STM32F would end up as an embedded controller
not just for audio, but also camera, buttons, power management,
date/time if you remove the CPU Card and it loses its time *and* also
as an SD Card reader.

 by going to 2-wire serial-jtag i've freed up a couple more GPIOs...
and then used *all* of them.  mad.  and extremely jammy.

>> but, i need help with the AXP209 datasheet (from someone who's chinese
>> would be great) - i'm not sure if the circuit i've got (shown at the
>> top of the news page) is correct - could someone please look at
>> section 9.6 of the datasheet and see if it's correct?  datasheets
>> here: http://hands.com/~lkcl/eoma/kde_tablet/
>
> The AXP202 datasheet might help, available in both chineese and english.
> The two seem very similar.

 ah superb.

> You can find a complete(?) collection of datasheets for the AXP series
> of PMUs at http://dl.linux-sunxi.org/AXP/

 thanks henrik.

 you'll be amused to know that i'm going to have to use LDO2 set to
2.5v as the mid-point for the headphone circuit.  means programming it
with a different setting from the A10.  fuuuun.