[time-nuts] FE5680 GPS Disciplined Controller Update

EWKehren at aol.com EWKehren at aol.com
Tue Jun 24 20:06:55 EDT 2014

Again we are talking past each other I am talking about temperature  
compensation with the DDS that ideally should be removed. Those steps  upset any 
In a message dated 6/24/2014 6:38:48 P.M. Eastern Daylight Time,  
holrum at hotmail.com writes:

Check  out the temperature control code in Lady Heather.  It uses a nice 
PID  controller algorithm (from Warren Sarkison) to PWM modulate a fan to 
stabilize  the environment around the Tbolt.  It can achieve millidegree range  
stability...  I have seen long term RMS values of the temperature plot  less 
than a few micro-degrees.   The standard Tbolt oscillator has a  rather 
horrible tempco...

I'll post some recommendations/findings about  various environmental 
sensors I tried while I was building my  weather/envionmental sensor package.   
Hint:  the  MS5611  pressure sensor chip is very nice.  Has 24 bit ADCs for 
the pressure and  temperature readings and produces very stable readings with 
a 100 Hz update  rate.
However it is disappointing that no one has stepped up  to tackle the  
temperature problem.           
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