Servo API
The Servo service allows to drive RC elements like servomotor
Its type has access to all common capabilities.
Functions​
| Function name and parameters | Action | Comment |
|---|---|---|
| control(self) | Displays service type graphical interface | Only available using Jupyter notebook |
Variables​
| Variable name | Action | Type |
|---|---|---|
| rot_position | Rotation position in °. | read / write: float |
| max_angle | Sets max_angle value, in degrees (°) (180.0 by default) | read / write: Float |
| min_pulse | Sets PWM minimum pulse value, in seconds (s) (0.0005 by default) | read / write: Float |
| max_pulse | Sets PWM maximum pulse value, in seconds (s) (0.0015 by default) | read / write: Float |
ROS topics​
| Topic name | Message type | Comment |
|---|---|---|
| /servo1_mod/variables/rot_position/read | std_msgs/msg/Float32 | value in radians |
| /servo1_mod/variables/rot_position/write | std_msgs/msg/Float32 | value in radians |
| /servo1_mod/variables/max_angle/read | std_msgs/msg/Float32 | value in radians |
| /servo1_mod/variables/max_angle/write | std_msgs/msg/Float32 | value in radians |
| /servo1_mod/variables/min_pulse/read | std_msgs/msg/Float32 | |
| /servo1_mod/variables/min_pulse/write | std_msgs/msg/Float32 | |
| /servo1_mod/variables/max_pulse/read | std_msgs/msg/Float32 | |
| /servo1_mod/variables/max_pulse/write | std_msgs/msg/Float32 |
Example code​
Example command from ROS topics​
Move the servo1 to 1.57 radians:
ros2 topic pub -1 /servo1_mod/variables/rot_position/write std_msgs/msg/Float32 data:\ 1.57\