How is this data being formed from the values given?

[Acetronics2]

Hi, Peter

I suggest you to try :

count = ( 1001 x Voltage - 9891 ) / 8

Alain

[retepsnikrep]

Thanks again for the ideas. Alain what makes yours special/sneaky?

I note that in my original table the 3rd character of the hex words 100V = $2C30 (3) in this case is never a letter A,B,C,D,E,F
Either I got lucky with my samples or something else is happening.

I was wondering if we are seeing the output from a 12bit ADC 4096 packed into those twelve bits.

[retepsnikrep]

Sorry I'm still a bit stuck.

Looking at this again lets assume my voltage data is being encoded into a 3 digit hex humber. (12 bits)? or is it a raw 10 bit non justified ADC result I am seeing?

Lets take 100V as an example $2C3 = 707

The position 3 is never > 7 and varies between 0 and 7 as the voltage rises and falls.

That feels significant, so what is going on?

150V for example = $447 = 1095

Grateful for any other ideas.

Or alternatively how can I prevent anything other than 0-7 appearing in the result?

[Jerson]

Hi Peter

Let us walk through this as per what I suggested

(100V-10)*126 = 11340 = $2C4C
(150V-10)*126 = 17640 = $44E8

Now suppose we drop the last nibble( divide by 16), you get $24C and $44E which is pretty close to the numbers you're seeing. So, the error must be in the formula being an approximation.

Hope this makes it easier for you to solve the issue

Regards

[retepsnikrep]

Thanks I think I have it now..