Description

The servocontroller node to move the 6 servos for wheels and the 3 servos for the robotarm

ros2 name: n10_servo_controller

wheel-servo-channels: 0-5, usual wheel enumeration

Setup

In order to access GPIO for I2C, the user running the node needs I2C permissions:

sudo usermod -aG i2c $USER

Open (file may not exist yet):

sudo nano /etc/udev/rules.d/99-i2c.rules

add these lines:

  SUBSYSTEM=="i2c-dev", MODE="0666"
  KERNEL=="i2c-[0-1]*", GROUP="i2c"

Reload the rules:

sudo udevadm control --reload-rules
sudo udevadm trigger

Finnally, you may need to relog.

Interface

subscribed

• /n10/servo_cmd_wheels std_msgs::msg::Float32MultiArray (6) : control wheel servos

  • from -π/2 ≐ pointing right to π/2 ≐ pointing left

• /n10/servo_cmd_arm std_msgs::msg::Float32MultiArray (4) : control robotarm servos

  • index 0: base_joint 0 ≐ pointing up counterclockwise
  • index 1: arm_joint 0 ≐ same as base_joint counterclockwise
  • index 2: correction_joint 0 ≐ same as base_joint counterclockwise
  • index 3: gripper state ?? ≐ open ?? ≐ closes