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Unread 20-11-2005, 09:01
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DonRotolo DonRotolo is offline
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Re: Rotary Position Sensors

Quote:
Originally Posted by Rickertsen2
...Btw 100K pots are required for the OI because it measures the current that flows through the pots....
Thanks for your other comments, with which I agree and will try out.

For the quote above, I disagree. I do not believe that the OI is reading the current, instead it reads the voltage. My thought is that the 100k limit is there to avoid issues with excessive current draw.

The specs of the OI state that the inputs are Analog, 0-5 volts. Also, IFI gives instructions for using a Y cable to connect two joysticks to the same port, which would double the current. Finally, they specify an 8 bit A/D which measured voltage (although I agree, they could measure current through a sense resistor - but why?)

IFI also states that any voltage below 0.05 volts causes an output of 127 (so the 'bot doesn't go into full reverse), and this is easy to do in code.

NEVERTHELESS. If IFI states so clearly "Always use 100k pots", who am I to argue??

Don
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