[ntp:questions] Re: Motorola M12+T interfacing

Richard B. Gilbert rgilbert88 at comcast.net
Thu Nov 25 21:11:55 UTC 2004

mattopia wrote:

>Hello all,
>Planning to interface an M12+T as a reference clock to establish a
>stratum 1 ntp server.  I have sourced the board and antenna from
>Synergy GPS.  I've found a fair amount of information on the software
>end of things, but have not found much on the hardware aspect.
>Synergy also sells a ~$70 interface board to convert the M12 board's
>output to rs232.  I'm wondering what those who have designed an M12
>solution have used -- the Synergy (or exit.com or similar) interface
>board, or have pieced together a component level solution to convert
>to rs232 voltages.  Motorola's guide suggested a Maxim product which
>is readily available on ebay for $12 in a quantity of 6.
>I'm assuming most have gone with the Motorola eval kit or something
>similar, but being a hobbyist, every dollar saved is a bonus.
>Matt Whitted
I bought the M12+T evaluation kit from Synergy.  I'm also a hobbyist (at 
home).  I chose the evaluation kit in order to avoid the problems of 
designing and constructing something to provide similar functionality.   
IIRC the evaluation board provides RS232 to TTL level conversion, a 
voltage regulator, battery backup and other goodies.

If I had it to do over again, I'd spend a little more money and get a 
GPS receiver that comes with a case.  The evaluation board has no 
mounting holes to allow you to fasten it to anything.

If you have the ability to "roll your own" go ahead.   If you have 
doubts, spend the money for a "plug it in and it works" solution.

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