- Oct 14, 2008I saw a post about this on the APRSSIG - did you get an answer yet? You

should only need a constant and a multiplier, since the response is linear.

Scott

Mark Cheavens wrote:>

>

> I am trying to work with the telemetry page on FindU. I have a

> telemetry value that requires the attached math to make it display

> the way I want. I haven't figured out how to make the math work to

> get it to display correctly. Any help would be appreciated.

>

> Sample URL:

> http://www1.findu.com/cgi-bin/tele1.cgi?call=PURG&last=96¶m=1&b=1.0&label=Purg_Repeater_Cabinet_Temp&units=Temperature&autorange=1

> <http://www1.findu.com/cgi-bin/tele1.cgi?call=PURG&last=96¶m=1&b=1.0&label=Purg_Repeater_Cabinet_Temp&units=Temperature&autorange=1>

>

> I am reading telemetry parameter 1.

>

> I need to take the value (Currently sitting on my bench in an air

> conditioned room!) with a value of 148

>

> I would LIKE to have the value in Degrees F (I know that C would be

> easier).....

>

> So here is the formula:

>

> ((Telemetry + Correction Factor) X 1.9608 Sensor Multiplier - 273.15)

> * 5 / 9 - 32 = F

>

> For this install the correction factor is 4.7.

> 1.9608 is the sensor multiplier (Constant)

> The rest if just the basic math...

>

> OR ((148-4.7)*1.9608-273.15)*9/5+32=TempF

>

> I don't understand how the a= b= and c= can get me there!

> http://www.findu.com/cgi.html#tele1 <http://www.findu.com/cgi.html#tele1>

>

> Any help would be appreciated!

>

> (I have figured out the easy linear ones in the past - Like this same

> one for voltage -

> http://www1.findu.com/cgi-bin/tele1.cgi?call=PURG&last=96¶m=2&b=.072254&label=Purg_Batt_Voltage&units=volts&autorange=1

> <http://www1.findu.com/cgi-bin/tele1.cgi?call=PURG&last=96¶m=2&b=.072254&label=Purg_Batt_Voltage&units=volts&autorange=1>

>

> (FYI - This is the output of an OpenTracker+ being used in an outdoor

> solar only radio site (Emergency Clinic) to record interior

> temperature for the batteries and battery voltage. - I do have it on

> the status line, but I don't like the resolution, and would like to

> plot it like I have done for the voltage) http://map.findu.com/purg

> <http://map.findu.com/purg>

>

> Mark

> KC5EVE

>

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