Insert a short shaft into the center hole.With the sensor plugged into the cortex (or a separate test bed): Mark Your Sensors Before Usingīefore you even get this sensor on your robot, plug it into the cortex and do some testing using the online window (eas圜) or the debugger window (RobotC). If you do, the sensor’s “stops” at each end of the arc will break, but more importantly the data will be meaningless. Do not install it on the shaft that is spinning more than one full revolution. If your arm is geared-the motor is turning at speed X and through gears makes the arm move at speed Y-be sure to install the potentiometer on the shaft that stays within that 250º arc.
That’s why you have to include this sensor at the start of your design process. And maybe you have a tight spot, in which it will never fit. It’s difficult to slap one of these on after the fact doing so usually involves taking the arm joint apart and changing all of your spacers, etc. This sensor, along with the optical shaft encoders (subject of my next post) require some advance planning in your robot design. Then when the arm lifts, its axle turns that inner white portion of the sensor to produce a reading. Wrong! You screw this thing onto a part of your robot that does not move. My brain wanted to screw this thing onto the movement arm itself. The small white inner part of the sensor is square and can rotate (hard to see until you’re holding one) the big red part is screwed onto the robot.
The hole in the middle of the sensor is square, and you run the arm’s shaft through it. Renegade Robotics Starstruck robot potentiometer can be seen in upper right corner, at the top of the forklift arm Why? Because this sensor can only turn about 250º. It is used on a component that has a rather small arc of motion, like a lifting arm. This sensor is not for a chassis or other spinning motor. This one, however, is not digital but rather analog-returning values from 0 to 4095 (RobotC) or 0 to 1023 (eas圜). Along with the 2 sensors mentioned in my previous post (bump switch and limit switch), this is one of VEX’s most reliable sensors, and it’s pretty durable to boot.
The aim of this series is to help teams that are new to using sensors have an idea of what is available and what they might like to use on their own robots.Īnd since this post has gotten kinda lengthy, here’s your Potentiometer Table o’ Contents: (a) installation, (b) mark your sensors before using, (c) test, test, test, (d) OMG I broke it, (e) how does it work? (f) uses. This is the second of a series of posts that examines each VEX sensor in turn.
0 kommentar(er)
