[time-nuts] Oncore 1pps driver & LED

Glenn glenn at net127.com
Thu May 4 14:55:30 EDT 2006

 I am hoping someone can help me with some basic electronic questions 
about hooking up the Oncore UT+.

I have a MAX233CPP two channel rs232 driver. I presume I can use the 
second channel to drive the 1pps on DCD line. Yes? I'll have a run of 
about 30-50' of CAT5, which *should* work. I should be able to adjust 
the 1PPS offset on the Oncore to account for this, plus the delay of the 

The 7805 +5v voltage regular appears to be plug&play. I don't think I'll 
need a heat sink for it.

The Linux PPS driver appears to only support kernel 2.4. And, I'd rather 
stick with a stock kernel on that box anyway. So, I'll follow Geoff's 
advice and run FreeBSD on an old Compaq for my timeserver. But, I'll 
probably test everything out on my linux box before I get around to 
building the FreeBSD box.

I'd like to put an LED near the Oncore module that blinks on the 1pps. 
What's the best way to wire this up?


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