2.5 vs 3.5 jack and some other considerations

Dmitry Shalnoff shalnoff at gmail.com
Thu Feb 17 09:28:47 CET 2011


On 16/02/11 23:28, David Lanzendörfer wrote:
>> Hi list,
> Hello list-user :-)
>
>> is anybody here from GTA04 developers?
> yes
>
>> if it's not late, would be great to hear some case concerning 2.5 jack
>> retention. That's only thing I found objectionable in the current tech.
>> specification. is it possible to change it in final PCB version to 3.5 standard socket to make it compatible with most widespread headphones standard?
> Well, I'm plagued by the same issue. Here where I live, all connectors are
> Ø3.5mm while the FreeRunner has Ø2.5mm.
> I talked with Nikolaus about this topic already, and it's not that easy.
> The board wouldn't fit into the case anymore,

that understandable reason, but ... I see simple compromise, which is, 
to my mind, quite suitable for device audience and relevant to the 
spirit of the project... this is not a big difference with 2.5 and 3.5 
socket pads. why not make just a bit wider pads under the socket to give 
a possibility to solder other jack for the people who would like to do 
that and ready to drill case hole to make it wider.

If I don't mistake ther is enough space over the socket in the case and 
even if not, the case easly can be modified by little filing.

at least (even if it stay in current status), what would be good to take 
into account this is the order of pins in the socket. Current GTA02 jack 
have non standard punout where is a 3 contacts jack just short one 
channel and to get normal stereo you need to get 4 contact jack and 3 
pins socket and resolder it by youself (that what I did, for example)

this adapter (which has similar order of contacts on the both sides) 
didn't work 
http://www.dealextreme.com/p/2-5mm-male-to-3-5mm-female-adapter-cable-white-14-5cm-23191


> so you would have need for a new one too...
> Good thing is, that we also are already planning the gta05, and there I'm
> organizing an amazing, cool and totally innovative new chassis in addition.
> Can't tell too much as long as the specs are not CC-License, but:
> It's TOTALLY cool ;-D

Heh :) that's sounds promising. would you like to make it public on 
early stage? it's open hardware project. let people to get involved.

Just one last think... it's about the case and screen size. I totally 
like current form-factor and, as designer, I found it very interesting 
and relevant to the idea of the project. I really like that hole and 
that's difference from hundreds of other mass-market pocket bricks. But 
the big minus of the current case that a limitation of the screen size. 
Probably, would be great to focus on form-factor "flexibility" and 
modularity of the hardware (as I suspect, you, probably, already 
planning something in this way).

Ideally that could be really great to have a chance to repack all 
hardware in selfmade case with _other_screen_ and other set of 
peripheral devices. (is LCD have a standard interface?) It would gives 
dramatically new abilities for individuals and small design companies to 
create customised portable devices.

anyway, thank you guys that you continue the project. I reckon that it's 
just a beginning of the big movement which eventually changes our 
understanding of the market and design of things.

best regards,
Dmitry

>
> best regards
> 	lev
>
>
>
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