From: Mark Ganson <mwganson_at_hotmail.com>
Date: Sat, 11 Apr 2009 14:06:56 +0000

>
> That's sort of where I was going. However I'd keep the
> firmware SD internal as a microSD card. Doing so removes
> confusion over which is which albeit at the compromise of
> a second user accessible slot.
>
> microSD has become quite cheap and a microSD socket will
> add less than US$1 to the BOM cost. The PCB footprint
> even including mounted card isn't much greater than a 56
> pin TSSOP flash part yet provides the trivial upgrade/replacement
> option as above.
>
> -john
>
> --
> john.cooper_at_third-harmonic.com

I have found there are 4 things that will most commonly render a portable music player unusable: 1) obsolescence, 2) defective internal storage, 3) damaged LCD screen, and 4) damaged headphone jack. You're going a long ways towards fending off 1 and 2 by using a standard type of memory card in place of a soldered in on-board memory chip, especially if you provide that 2nd expansion slot, since doing so allows for twice as much potential future memory expansion. For 3 and 4, if I were designing a player I would want to first build it like a tank, but also make the LCD and headphone jacks both easily user-replaceable. This means the LCD should be connected to the system board via some sort of socket rather than being soldered in directly -- and the LCD used should be the same used on some popular brand and model that the user could acquire in order to scavenge a replacement LCD. Similarly, the headphone jack should be of some standard type that is connected to the system board via lead wires, which can easily be spliced into when replacing a bad jack.

--Mark

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Received on 2009-04-11