[time-nuts] Electronics Question

[Steve Longcor]

The M12 is 3V logic.  I assume the net4501 is 5V logic, so you may need 
level shifting for the connection to work reliably and not damage the M12.

Steve

On 7/27/2011 2:02 PM, Chris Albertson wrote:
> No, you can't simply wire two logic outputs together.  One or the
> other logic state is "stronger" (Yes I know poor analogy) and "wins".
> The details are here.
> http://en.wikipedia.org/wiki/Wired_logic_connection
>
> But it is pretty easy to remove a chip especially if you don't care if
> you damage it.  The classic method is to clip all the leads from the
> IC toss out the chip then de-solder the leads one at a time.     When
> chips cost 2 cents it's better to trash them than waste time with
> complex rework methods.  (Different story for expensive parts.)
>
>
>
>
> On Wed, Jul 27, 2011 at 1:48 PM, Jason Rabel
> <jason at extremeoverclocking.com>  wrote:
>> This is only pseudo time-nuts related...
>>
>> I'm wiring up (yet another) net4501 with a Motorola M12 GPS..
>>
>> This net4501 has the RS232 driver chip there for the 2nd serial port (previous units I purchased didn't, which made life easier for
>> me).
>>
>> Can I solder my GPS tx/rx lines on the ttl side of the RS232 chip and will it work? Or will the rs232 chip hold the voltages
>> low/high because there is no signal on the input sides?
>>
>> This is just kind of "for future reference" question. I half wasn't sure if it would work, and half didn't care to try and solder a
>> wire to a TSOP lead. So I bought a Max3222 PDIP and can make a proper interface. The prototype board will also give me room for some
>> extra LEDs. ;)
>>
>> This is kind of an experiment to see how a regular M12 compares to the M12+T for NTP purposes. I'll probably build a fresh NanoBSD
>> image because I need to modify a line of code in NTPns to remove a TRAIM command that makes the regular M12 PPS stop. I also want to
>> build the latest regular NTP distro.
>>
>>
>>
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>
>