Package ROS for the Adafruit PWM Board

Usage

Used for Adafruit 16-Channel PWM / Servo HAT for Raspberry Pi.

Listen for PwmDeviceArray messages on /cmd_pwm_board by default and send accordingly the commands to the board by I2C.

To test the package without any prior configurations, launch :

roslaunch adafruit_pwm_driver test.launch

It will run the driver and the interpreter with the example configuration.

Configuration

This package needs to be configured with a YAML config file. An example is in the config folder with and example launch file.

Example :

pwm_board_config:
# If your board doesn't handle inputs (sensors) then defining device with a data_type.type:'inputs' will make the
# node throw an error
  data_types:
    'motor100':
      type: 'output'
      range: [-100,100]
      accel: 10
    'attopilot':
      type: 'input'

  device:
    'thruster_left':
      'pin': 0
      'data_type': 'motor100'
    'battery1_voltage_raw':
      'pin': 8
      'data_type': 'attopilot'

Nodes

• adafruit_pwm_driver.py

  • Parameters

  pwm_board_config/device : list of devices connected to the board
  pwm_board_config/data_types : list of data types
  

  • Subscriptions

  cmd_pwm : PwmCmdArray
  

  • Publications

• adafruit_cmd_interpreter.py

  • Parameters

  pwm_board_config/device : list of devices connected to the board
  ~sub_name : topic on which the node suscribe
  

  • Subscriptions

  sub_name : PwmDeviceArray (default : cmd_pwm_board)
  

  • Publications

  cmd_pwm : PwmCmdArray
  

Notes

The command is in ms. For example 1000 is minimum, and 2000 is maximum pwm.