Servo Board API
The kit can control multiple servos simultaneously. One Servo Board can control up to twelve servos.
Accessing the Servo Board
The servo board can be accessed using the servos submodule in sbot:
from sbot import servos
Servos are accessed by their index: the servo connected to position 0 on the board should be accessed as id 0, and so on.
The servo board is labelled so you know which servo is which.
!!! tip Remember that lists start counting at 0.
Setting servo positions
The position of servos can range from -1 to 1 inclusive:
# set servo 1's position to 0.2
servos.set_position(1, 0.2)
# Set servo 2's position to -0.55
servos.set_position(2, -0.55)
You can read the last value a servo was set to using similar code:
last_position = servos.get_position(11)
While it is possible to retrieve the last position a servo was set to, this does not guarantee that the servo is currently in that position.
How the set position relates to the servo angle
You should be careful about forcing a servo to drive past its end stops. Some servos are very strong and it could damage the internal gears.
The angle of an RC servo is controlled by the width of a pulse supplied to it periodically. There is no standard for the width of this pulse and there are differences between manufacturers as to what angle the servo will turn to for a given pulse width. To be able to handle the widest range of all servos our hardware outputs a very wide range of pulse widths which in some cases will force the servo to try and turn past its internal end-stops. You should experiment and find what the actual limit of your servos are (it almost certainly won't be -1 and 1) and not drive them past that.