On Sun, May 15, 2011 at 6:08 PM, Andrew Errington
<[email protected]> wrote:
> On Sun, 15 May 2011 14:20:16 Nick Rout wrote:
>> On Sun, May 15, 2011 at 2:45 PM, Steve Holdoway <[email protected]>
> wrote:
>> > http://www.newit.co.uk/forum/index.php?topic=1810.0 any use??
>>
>> Certainly worth bookmarking for the future, but you can't get the
>> serial console without the proprietary jtag connector.
>>
>> However I wonder if I can jimmy one up. The device has two ports that
>> plug into the jtag box. One is a 'uart' connector, the other is
>> specifically for jtag. The proprietary box seems to serve two
>> purposes, a proper jtag connector AND a gateway between the uart port
>> on the device and a ftdi serial usb chip. So... I guess someone with
>> knowledge of the pinouts on the 4 pin uart connector, and some
>> electronics nous could try and get the serial part going...
>
> Hi Nick,
>
> The adapter kit is US$39.  It's hardly expensive.

Plus $38.05US shipping via fedex, and whats more globalscale seem to
take forever to actually ship, from my looking around on the net.

>
> This wiki indicates the order of the 4 pins in the serial connector (at the
> bottom of the page):
>
> http://www.plugcomputer.org/plugwiki/index.php/GuruPlug
>


Thanks for the link, i found the same info elsewhere, good to have two
sources though.

> If you only need the serial interface

Now I have twigged that the serial and jtag funtionalities are
different, and that the globalscale box just happens to supply both, I
am working towards a serial/usb connection.

>(not the JTAG) then you could probably
> hack a USB->RS232 converter.

I am looking at using this method:

http://buffalo.nas-central.org/index.php/Use_a_Nokia_Serial_Cable_on_an_ARM9_Linkstation

to get a serial connection. The uart pinouts are 3.3v level, not true
serial, so this should work (again it was referenced in some guruplug
forum.)

I just bought a nokia cable on trademe, and am looking forward to some hacking.

Now I just need the connector, 4 pin Molex PicoBlade™ 51021 Series
connectors (1.25mm pitch).

> Inside the converter (an FTDI one would be
> best) is a USB UART chip and a level shifter.  The UART deals with the USB
> interface and the RS232 protocol.  There are three key wires between this
> chip and the level shifter: Data In, Data Out, and Ground.  The level shifter
> simply converts the 5V or 3.3V from the USB UART into +/- 12V or so needed by
> a true RS232 device.
>
> If you buy a converter you need to peel off or crack open the case and
> identify the two chips.  Find out if the level converter is running at 3.3V
> or 5V, and the model number of the FTDI chip (the USB UART).
>
> If the level converter is running at 3.3V then you can hook up two wires
> directly from the Data In and Data Out pins on the FTDI.  You also need a
> Ground wire.  Run these to the serial connector on the GuruPlug.  (You don't
> need the 3.3V wire).
>
> If the level converter is running at 5V then remove it and discard it.  Find
> out which pin on the FTDI chip sets the output to 3.3V and change it, then
> hook up Data In, Data Out and Ground as above.
>
> Assuming you don't need another level of inversion this should give you a
> console interface on /dev/ttyUSB0
>


That's all good info, hopefully the nokia thingy will avoid needing to
do all that, providing I can find the connector (as above).

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