using continuous rotation servos 'instead' of geared motors
June 30, 2010
For the sake of simplicity i will use the start here robot to ask my question, as the controller in the robot I am building here will be no more complicated (2 motors, one sensor) than that, and use the same processor (picaxe28x1)
The question is; Would I be able to use continuous rotation servo's instead of geared motors as the means of transport.
The differences and complications i've run into are -
- The inputs for a motor may be set high and low, and left in that state while the picaxe does other things like measure distances and rotate a servo.
- In continuous rotations servo's though, the pulse needs to be continuously generated to keep them rotating, meaning that the picaxe cannot complete any other processes (like measure distances with sensor) while it is instructing a servo to continue turning.
I've been trawling through search results but i'm not finding anything that is helpful.
The reason I ask this is because the continuous rotation servo's will be used as the powerhouse for my next robot as they are relativley high torque and are easily fitted onto the chassis.
Further information - The robot is controlled of a picaxe 28x1 and a 08M
In autonomous mode, the 28x1 will be active, and doing exactly what the start here robot does, navigate with an IR sensor.In R/C mode, both the 28 and the 08 will be recieving the same information from an RF reciever and interpreting it differently. The 28 will be used to navigate (via the two continuous rotation servos) while the 08 will take care of a 2-servo turret with wireless camera.
EDIT i guess this means it needs to be able to have the servo's rotating while it is in waiting for a signal with the serin command - something i think is only possible with a changed pinstate (ie, powering a motor) rather than a pulsing signal (to control the servo)
Because the camera is controlled separately, the robot will be able to drive and rotate the turret at the same time.
Each controller recieves the same single control byte. four bits are interpreted for movement (Forward, back, left right) by the 28, and it disregards the other four. The 08 interprets the other four bits for turret movement (pan left, right, up, down) so that in this way 8 boolean signals can take care of the whole range of motion in the robot.
I figure that if all else fails i can just resort to rewiring the servo leads directly to the servo's motor and running them like normal geared motors.
Anyway, any advice/code snippets or thoughts in general would be appreciated.