Hello!

I'm making a program with RobotC which has to read the rotation position of a NXT motor. I use nMotorEncoder(motor) but this function gives me absolute position of the encoder. If I move the motor backward, my measure turns to 360 and goes down, and I want it as -1ª, -2ª... It's a problem for me too that my measure passes from 360º increasing to 1º, and not to 361º
Is there a simple solution to this?

Regards,
Albert

PD: I promise you to upload my program when I finish, a self-balancing robot with a Gyroscope.

Hi Albert

You can reset the encoder to whatever value you want anytime, here is the command to do this.

nMotorEncoder[motorA] = 0; // reset encoder to 0

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Good luck with your project B-)
Scott

Hi Albert,

You will need a new variable or a conditional statement to reach the behavior you need.

Out of curiousity, does resetting the encoders affect the motors' PID control at all?

Regards,
Xander

mightor, this is the question i'm trying to solve, because if I design a control it will run properly only between 0 and 360 degrees, not mor than this or with negative rotation.

What I want to use is the rotation position without encoder reset to obtain, for example, 450º or -80º,-500º. I don't understand why there isn't a function to read rotation in this way, because in the window "NXT Device Control Display", in all "Tacho" columns this kind of result is given.

EDIT: I solved this problem. The problem is that when you put the function degreesToRadians it returns you a value between 0 and 2*PI radians. To solve this, I used a definition #define DEG_RAD 0.01745 and I multiply this with the encoder value.

PROBLEM SOLVED!!!