[Gta04-owner] GTA04A5 - was 8mW sleep for Beagle Board

[Dr. H. Nikolaus Schaller]

Am 10.01.2013 um 00:36 schrieb Butrus Damaskus:

> On Mon, Jan 7, 2013 at 11:09 PM, NeilBrown <neilb at suse.de> wrote:
>> On Mon, 7 Jan 2013 18:55:52 +0100 "Dr. H. Nikolaus Schaller"
>> <hns at goldelico.com> wrote:
>> 
>>> 
>>> Am 07.01.2013 um 04:56 schrieb NeilBrown:
>>> 
>>>> On Fri, 4 Jan 2013 11:51:38 +0100 "Dr. H. Nikolaus Schaller"
>>>> <hns at goldelico.com> wrote:
>>>> 
>>>>> 
>>>>> Am 04.01.2013 um 10:21 schrieb Radek Polak:
>>>>> 
>>>>>> On Thursday, January 03, 2013 01:09:53 AM NeilBrown wrote:
>>>>>> 
>>>>>>> On Tue, 1 Jan 2013 16:29:45 +0100 Radek Polak <psonek2 at seznam.cz> wrote:
>>>>>>>> Hi,
>>>>>>>> i found this mail:
>>>>>>>> 
>>>>>>>> https://groups.google.com/forum/?fromgroups=#!topic/beagleboard/GXqO9rRsy
>>>>>>>> Cg
>>>>>>>> 
>>>>>>>> Do i count right? 8mW means 2mA on 4V battery. I wonder if we could apply
>>>>>>>> this also on GTA04.
>>>>>>> 
>>>>>>> The first patch is a useful guide for writing similar code for the GTA04.
>>>>>>> The remainder aren't particularly relevant I think - the relevant
>>>>>>> functionality is already in mainline.
>>>>>> 
>>>>>> I wonder about the HW changes - if they can be also applied on GTA04.
>>>>> 
>>>>> It is on the GTA04A5 todo list. At least the "disable 26MHz oscillator" patch.
>>>>> 
>>>> 
>>>> What else is on the A5 todo list?  I'm particularly hoping that inserting the
>>>> headset plug will cause an interrupt.
>>>> Any chance of seeing the schematics before you commit to them :-?
>>> 
>>> Yes, that is planned to be finalized this week.
>>> 
>>> Important (i.e. kernel relevant) changes are so far:
>>> * power down 26 MHz oscillator through switching off VPLL1 (tbc.)
>>> * LIS302 option removed completely
>>> * LSM303 option removed completely
>>> * BMA180 / HMC5883 replaced by BMC050
>>> * GPS-chip has 1 second pulse - connected to GPIO114 (was connected to LIS302)
>>> * IrDA can be separately enabled/disabled (GPIO175 or TGPIO7 - tbc.)
>>> * TCA8418 replaced by FFC connector (for external keyboard)
>>> * there will be an optional connection that a 3G wakeup can simulate pressing the power key (tbc.)
>>> * switch in headset jack will pull down a GPIO if no headset is inserted (tbc.)
>>> * RESET-OUT from UMTS module connected to a GPIO so that it is possible to detect if it is really running (tbc.)
>>> 
>> 
>> Sounds good. thanks.
>> 
>> Though I wonder a bit about IrDA - does anyone actually care about that?  I
>> would imagine that most situations that would once have used IrDA would not
>> be using bluetooth.
> 
> I think IrDA maybe easier to use with MCU's (and doesn't interfere
> with WiFi in 2.4GHz)...
> 
>> The OMAP3 is capable of generating CIR (Consumer IR) signals which most
>> consumer electronics remote controls use.  That might be more useful, however
>> it needs to be wired differently.
> 
> In order to generate CIR a simple GPIO with PWM connected to a cheap
> IR LED might
> be sufficient...
> 
>> The CIR signal goes out on the uart3_cts_rctx  pin, where as IrDA goes out on
>> uart3_tx_irtx - So I don't think they can use the same IrLED (???).
>> 
>> 
>>> Some options are a little critical and can't be tested before building the first devices.
>>> So there will be hardware options to disable/remove them if they don't work well enough.
>>> 
>>> Non-software related changes replace some obsolete components, improve the
>>> GPS antenna switch, reduce noise generated by SD card interface, and make a
>>> really complete case kit possible with components from continued production.
>>> 
>>> But at the moment it does not look as if there is any demand for a GTA04A5 board.
>>> So far there is exactly 1 preorder for a GTA04A5 board...
>> 
>> That's a shame.  Maybe demand will pick up as Christmas gets further and
>> further into the past...
>> 
> 
> Well, for many people 555€ is a lot of money... :-/

Yes I know.

But there is something which cheaper alternatives don't offer:
* schematics & documentation available
* a community to discuss details
* made in Germany
* almost all components are available through big distributors in small quantities, i.e. it is possible to take it as the starting point for your own design
* cutting edge Linux available (currently kernel 3.7)
* actively supported for long time (2 years now - if you include the GTA01/02 it is the 6th year now)
* nice platform to experiment with
* reuse instead of throw away and replace with something completely incompatible/different
* you know whom you support
* opportunity to make proposals for future development and bring in ideas
* chance to port any operating system where you have the sources and a chance to get it 100% running (not only 90% because of lack of documentation)

Unfortunately some of these features make it impossible to get down to a lower price (production of small quantities in central Europe) without having someone subsidize it.
 
BR,
Nikolaus