CRServo
CR Servo, or Continuous Rotation Servo, is a servo that can rotate indefinitely in either direction. CR Servos typically have higher torque and can achieve a wider range of speeds compared to standard servos. They are a versatile component in robotics, providing continuous rotation and power for various applications.
Programming these servos are similar to setting the power on a DC motor. There are 3 steps, setting the power, sleeping the program, and then turning off the power.
Setting the power
What this code does is that it tells the CR servo what direction to move and how fast to move it. If the power is positive, the CR servo moves counter-clockwise. If the power is negative, the CR servo moves counter-clockwise. The CR servo power ranges from -1 to 1. The greater the magnitude of the CR servo, the faster it goes! The power doesn’t have to be a whole number either! It can be a decimal like 0.1 or -0.7.
Sleeping the program
By calling this block, the program doesn’t execute for the specified amount of milliseconds. This may seem dumb but it has an important purpose: it gives the CR servo direction in step 1 time to move the robot. Just setting the power of a CR servo doesn’t make the robot move! Instead it defines the CR servo’s behavior. To let the CR servo move the robot, you need to give it time, literally! Sleeping the program will allow the robot time to move around.
Stopping the robot.
To stop the robot, set the power of the CR servo to 0.
By completely cutting off the power the CR servo receives, it will completely stop.
Although the robot will automatically stop moving when it has fully executed its code, setting the power to 0 is a helpful way to ensure the robot moves precisely how it was intended.
Typically steps 1 and 2 are repeated several times to create more complex movements before stopping the robot. Step 3 may be incorporated, however, to allow other parts of the robot, like a claw or slide, to move before resuming locomotion.
You can also reverse the direction of the servo. Which will invert the power to the servo.
This is useful when multiple servos power the same mechanism like a robot arm but are attached facing each other. By reversing the direction to one of the servos, controlling the servo becomes much easier as the same power input will make both servos turn the same direction, synchronizing their movement. This can prevent mechanical failure and overloading the servo.
CR Servos have many uses in FTC. They are handy as a miniature motor, helping to power light and more compact devices.