On 8/27/05, Julien Jassaud <sojastar@...> wrote:
> Thanks to all for your suggestions, but I finally solved the problem
> which was indeed electrical and not related to software. I once red
> on this mailling list or on the forum that serial signals should be
> 3.3V. This is why I used a ATMEGA8L, powered by a 3.3V power supply.
> I finally decided to give it a try with a 5V power supply and it
> worked instantly. So it looks like the gumstix serial ports can
> handle 5V signals and even need a 5V signal.
Hmmmm. I find this quite suprising.
On the robostix, the serial signals are converted from 3.3v to 5v on
the way out and 5v to 3.3v on the way in. So the gumstix will
definitely work with 3.3v signals (and that's in fact what the
waysmall boards provide as well).
Did you have a crystal connected to the ATMEGA8L? If so, what
frequency was it? At 3.3v, the max frequency supported by the ATMEGA8L
is 8 MHz. At 5v you can upto 16 MHz.
I'm really dubious about the 5v thing and I think your problem is
really something else.
Vancouver, BC, Canada