Re: [Gumstix-users] clarity on the console-hw

[Paul F. S. <pa...@se...>]

Thanks Dave!  Your annotated photo is very helpful.

So, when I'm doing my programming, would I open up two serial ports, 
/dev/ttyS1 (STUART) and /dev/ttyS3 (HWUART), and turn on and off RTS and 
CTS (which I'll use to control DTR) through S3, but transmit/recieve 
through S1?  Mucking around with RTS & CTS on the HWUART won't interfere 
with the ethernet connection that shares the HWUART lines?

Looking through my notes, I agree that pin 1 should be DTR.

I would rather not have to do driver changes if at all possible.  (my 
data rate is 19200, although the DTR (hacked via CTS) and RTS values 
will be static for hours, so any data rate would be fine for those.)

Paul
On 3/16/2008 11:12 PM, Dave Hylands wrote:
> Hi Paul,
>
>   
>>  So what do you recommend for me to build out something that will use the
>>  FFUART on the console-st, and have DTR set and RTS cleared?  I am happy
>>  to hardwire one of them - eg I could tie DTR to VCC.  I would like to
>>  have at least one under software control (I plan on using Perl or
>>  Python, since my C skills are old and weak).  Is there something off the
>>  20 pads (U3) that would be easy to control? What about pulling the Y0
>>  CTS signal?  I don't plan on using the USB port, so I could even cut pin
>>  1 on U$18 if needed.
>>     
>
> You could use almost any of the GPIO lines on the 20 pin connector and
> wire it up. It would most likely require some driver changes in order
> to get CTS working properly, although it depends on the data rate that
> you need to achieve.
>
> If you go this route, I'd still probably get the console-HW, since it
> has the CTS/RTS lines run through the RS-232 voltage converter.
> You could then cut traces to wire up the STUART port instead. I have a
> photo here that shows how to wire up the TxD and Rxd:
> <http://davehylands.com/gumstix-wiki/WaySmall-STUART/WaySmall-Back.png>
>
> The black signals are wires you need to add. The dotted red lines are
> traces on the other side of the board which need to be cut. It also
> has the HWRTS and HWCTS lines labelled. You would want to cut both of
> those, and add a wires from your GPIO lines.
>
> According to this:
> <http://pinouts.ru/SerialPorts/sgi8_pinout.shtml>
> pin 1 would correspond to DTR.
>
> You should check your cable to see if it's wired through. You can probably
>
>   
>>  I asked a similar question 2 weeks ago, but you and steve both
>>  recommended the HWUART board - but it looks like I would have to give up
>>  my netMMC board if I did that.
>>     
>
> Sorry - that was a slight bit of misguiding on my part.
>
>