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Unread 29-01-2005, 00:24
MyFeetHurt MyFeetHurt is offline
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AKA: Christine Laing
#1018 (RoboDevils)
Team Role: Mentor
 
Join Date: Jan 2005
Rookie Year: 2005
Location: Indianapolis
Posts: 1
MyFeetHurt is an unknown quantity at this point
Re: Hall Effect Sensor.

Hey, Stu, it's Christine. I did some calculations.

Wheel radius = 4", Robot speed = 10 ft/sec, gear by sensor has 45 teeth

2 * pi * 4" / revolution

* 1 revolution / 45 teeth

* 1 sec / 120 "

* 1000 mSec / sec

= 4.65 mSec / tooth

In other words, you can't do this by polling the sensors in a 26 mSec cycle, and you probably can't do it in the fast cycle either.

I think the right way to do this is to hook the sensors to a digital counter and poll the counter. I could be wrong. I don't know squat about counters, it's after midnight, and I can't remember how quickly the fast code cycles.

I won't be there this weekend. See you all Monday.