fpga

[gaks]

I have to check Hall sensor output. It produces 2.5 volts. But when I connect using FPGA, it shows some raw data 8160. How to get the accurate voltage?

[crossrulz]

Which FPGA card are you using?  What is the range of the Analog Input?

[DAD]

What hardware are you using?

Some hardware will return a fixed point value that is scaled and some will return the raw A/D counts and you've got to convert that.  The latter sounds like your case.  You need to know the number of bits in your A/D and the input range in order to calculate the voltage per A/D count.

[dan_u · Accepted solution]

This sounds like the FPGA has a -10..10V input with 16 bits.

The range -32768..32767 (16bits or I16) corresponds to -10..10V.

The value you're getting (8160) corresponds to 2.49V.

[SLee2004]

You have to get the LSB Weight and Offset Values from the modules and use them to convert the readings into voltages.  See link below.

http://digital.ni.com/public.nsf/allkb/2BDBB541D421673A8625752E005F4B32

[gaks]

i am using pxi-7842R i have connected the output of hall sensor to SCB 68 . i want to convert the RAW data to actual voltage ...

[gaks]

hey this range is correct but...pls tell me how to configure it for my actual voltage output i.e 2.49 v...i am using pxi-7842R

[dan_u]

The FPGA does not support floating point numbers (well in LV FPGA 2012 it does support SGL).

To transform a I16 value into -10..10V just divide the I16 value by 3276.75 (multiply by 10 and divide by 32767.5).

[gaks]

actually i m new..i dont know how to perform that action can you explain it please

[dan_u]

If you don't know how to perform a simple division I would recommend going through the LabVIEW Tutorials...