AVR-Chat

Chuck Hackett wrote:
> I have been able to generate output from the USART on the Butterfly but my PC
> (Dell Inspiron 8100) doesn't see it.
>
> On my scope I can see that data is being generated ("X"s at 100ms intervals) but
> I get nothing when I bring up HyperTerminal.  I've tested the HyperTerminal
> connection and it is working.  On the scope I can see the start bit, data and
> stop bit.  I'm using 38,400 baud, 8 bit, no parity, 1 stop bit.
>
> The only thing I can think of is that the signal does not have enough swing
> above and below zero.  My scope shows Mark as about -2.75v and Space as about
> +2.25v.
>   
   This is probably not enough voltage swing for the RS-232 receivers in 
your PC port.  You might want to insert a TI75232 (MAX232 clone, much 
less expensive) in between your Butterfly and your PC.

  I am expecting to have a Butterfly here soon myself, so i am looking 
forward to the same sort of fun you're havingm Chuck.

tom