On 06/29/2012 01:38 PM, Mark Benson wrote:
I work with a
lot of embedded boards these days. Design wise, I
rather like the Raspberry Pi.
It is a nice piece of kit, especially at the price point. For
embedded or semi-embedded work it's really nice, my only gripes are
the SD IO speed is terrible, and the 5V power input is via a USB
Micro connector not a 2-pole barrel connector which would have been
more 'standard'.
I'm sorry, but this is flawed reasoning. MicroUSB *IS* a standardized
connector, available everywhere, with the same pinout and identical
connectors. Those coaxial power connectors...Hey, I like them too,
but...There are several outer diameters, and several inner diameters,
and every combination is made, sold, and...designed into products.
There is no standard coaxial power connector.
Then, what's the polarity? Center positive or center negative? And
what voltage? Current rating? Oh, is it even DC? If so, regulated or not?
One may say, "Bull, I have these two boards here, and they use the
same one!" ...Yes, I have at least four that use the same one. And
another dozen or two that use completely different ones. Coincidences
happen. There is no standard. MicroUSB really was the correct design
choice here.
-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA