[time-nuts] Thunderbolt Controllers

Hal Murray hmurray at megapathdsl.net
Mon Jul 7 17:11:29 EDT 2008

> My pendulum produces pulses at a rate of one per second. That signal
> clocks a latch that samples the less significant bits of   my
> reference oscillator  (100kHz or 1MHz) in a counter. 

> but what I would really like is a clock showing UTS in a form that
> can be compared to a clock. 

> That means one second audible pips and a marker on the minute. Just
> seeing numbers rolling over on a computer is not good enough to check
> the timing of the second hand of the clock. You need ear - eye
> coordinated signals. With WWV I can compare to 1/20th of a second. 

I haven't quite figured out what that means.  How do you feed WWV to your 
data logger?

If you have a TBolt, you get a PPS, a 10 MHz, and a RS232 data stream.

If you start a counter with the TBolt PPS and stop it with your pendulum PPS, 
that will tell you the offset.  If you want minute markers, you need to parse 
the serial data stream.

> Although I have programmed systems in a variety of languages in my
> working life, the only languages that have stuck are Fortran and
> Basic. All the rest are forgotten after a year or two. I do not wish
> to start again to learn a new system just for one task, and it is
> obvious that there are so many micros abroad and none of them is going
> to be universally useful for future tasks. 

If future tasks are likely to be interesting, then I'd suggest that you pick 
a manufacturer that looks good and give it a try.  Best would be one that a 
friend uses so you can get some help if you need it.  All the manufactures 
make a broad range of chips with various I/O devices and different sizes of 
RAM/FLASH and different numbers of pins.  Mostly, they are all very similar 
and use the same tools.  Scan the selector chart and pick a chip that has 
what you need.  Or use a bigger one on a board you like.  The cost of the 
chip is tiny relative to everything else.

If I was doing what I think you want to do, I'd probably use c in an AVR.  
That's just because that was the last tiny system I worked on and I have some 
in my junk box.

Another approach would be to horsetrade with a friend who likes writing that 
sort of software.

These are my opinions, not necessarily my employer's.  I hate spam.

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