[time-nuts] multi input counter

Jim Lux jimlux at earthlink.net
Fri Oct 7 03:08:39 UTC 2011

On 10/6/11 4:24 PM, Magnus Danielson wrote:

> Consider that you have 7 digits of time-stamp value and 8 digits of hex
> code for time-stamped inputs and a carrige return, you need to output 16
> bytes. Considering that it takes 32 read-outs a second in peak. This
> means 512 bytes a second or a rate of 5120 baud needed, so 9600 baud
> output will do just fine. The time-stamper clock can count in BCD to
> make conversion cheap (and easy to code, just slab 0010 on top of
> digits). A 64 bit wide FIFO is needed to store time-stamps, as they can
> come at high burst rate but low average flow.
> It's doable and not too much work to cook up. I did something similar
> before, but I just can't find the code lying around. Sad, since it had
> the serial transmitt code and FIFO stuff more or less what we need.

That's basically what I was thinking..   9600 bps is also slow enough 
that you can do something on the receiving end like open the file, add a 
line, close the file, so it makes rolling over files every hour or 
whatever easy.

The experiment I have in mind will last about 2 months, with the batch 
of oscillators cycling in temperature either on a 100 minute cycle or a 
24 hour cycle. (Low orbit or earth/mars rotation period)

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