Correct 100K Pot readings

[SimRandy]

hi all,

pete, if i am not getting the high scale values that you say axis (my pots) should have. you know 16,000??? to -16,000 or so, using 100K pots, then will i get poor results. must i redo my pots so i get the highest values i can when calib.

randy

[Pete Dowson]

if i am not getting the high scale values that you say axis (my pots) should have. you know 16,000??? to -16,000 or so, using 100K pots, then will i get poor results. must i redo my pots so i get the highest values i can when calib.

I don't think so. The range -16k to +16k is not the input from the hardware in any case. That range is the one that is established by calibration in Windows, and by FS scaling thereafter. You should be doing that anyway before even thinking about using FSUIPC, for example.

To take one example, the ISA EPIC analogue inputs are 0 - 255 maximum, and calibrated to that by the EPIC Joystick program. Even then most pots won't give you even as many as 256 discrete measurable positions. The pots used on the PFC equipment (yokes, rudders, throttle quadrants) all give a maximum range of only 0-127 (usually significantly less), and of those there are only about 40 discrete positions (i.e the numbers jump in 3's).

Check the numeric input from any joystick, I bet you'll find the same. Even if you got -16000 to +16000 you'll probably find the increment between positions is about 320 or more.

In the end, what's important is how many different values your pots can provide The more the better, as that means more precision. It is for precision that many makers turns to optical systems rather than pots in the first place.

Regards,

Pete

[airforce2]

Another good option is to use Hall Effect RVDTs...they provide very good resolution and are generally much cheaper than optical encoders.

Cheers

[lefteris]

Another good option is to use Hall Effect RVDTs...

Cheers

And for those of us who didn't know what a "Hall Effect RVDT" is, I found this link which may be of interest:

http://www.micronas.com/products/overvi/index.php

[airforce2]

RVDT = rotary variable differential transducer