Re: PI TNC - progress report.
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From: gm8bpq ;
Subject: [Raspberry_Pi_4-Ham_RADIO] Re: PI TNC - progress report.
Sent: Fri, Sep 21, 2012 12:28:19 PM
--- In Raspberry_Pi_4-Ham_RADIO@..., ve2hom Pascal wrote:
> Hi John,
> This sound very cool, give us news about your project. Do you plan
> to make these board available to sell ?
> 73 de Pascal
> Le 20/09/12 16:27, John Wiseman a écrit :
> > Hi,
> > For those fairly new to the group, I have been working on a TNC for
> > use with the pI that is the same size as the pi and plugs into the
> > expansion header. The prototype was a TNC-X, with a 26 way header
> > superglued to board. There is a photo of it on the home page of this
> > group.
> > I've now received the first PCB's, and built a couple. There are
> > photos at https://dl.dropbox.com/u/31910649/S1300001.JPG and
> > https://dl.dropbox.com/u/31910649/S1300002.JPG. The TNC is largely
> > based on the TNC-X, but I've replaced the serial port with an i2c
> > connection, so more than one can be connected to the PI. The current
> > board has a mini-DIN radio connector, but I find mini-DIN plugs very
> > difficult to wire, and the connector is just too high to stack
> > properly, so the final version will probably have a DB9. I've written
> > a linux driver that takes the i2c data stream, and converts to a pty
> > that can be used with the normal linux ax.25 kissattach program. All
> > this seems to be working.
> > I've a couple of developments in the pipeline. One is to replace the
> > MX 614 modem, hopefully with a PIC based solution. Although the 614
> > works very well, it is relatively exensive, and only works at 1200
> > baud. I hope to be able to run at 300 for HF use. I've also bought a
> > couple of RFM22B modules. These are tiny 100 mW 434MHz data
> > tranceivers - see
> > http://www.sparkfun.com/datasheets/Wireless/General/RFM22B.pdf. I plan
> > to do a version of the TNC using this module.
> > A version using the FX 489 modem for 9600 baud links is planned, nut I
> > haven't started work on that yet.
> > 73, John G8BPQ