wsnewman / usb_relay_wsn

usb_relay_wsn

A ROS node to control the states of relays

Setup

Follow the Getting Started guide of the usb_relay module, as well as the next step, Changing the name of a module.

Usage

To start the node from the command line, run rosrun usb_relay_wsn ros_relay_bridge.py. This will listen for service calls for each relay, using each relay's name as the topic. If multiple relays have the same name, they will be controlled together.

It is recommended to namespace this node. To do this from the command line, run ROS_NAMESPACE=relays rosrun usb_relay_wsn ros_relay_bridge.py. This will prefix each relay with relays, so a relay with a name of serno will be controlled from /relays/serno.

This node will listen for service calls using the SetRelay service type. It will publish relay states with the RelayStates message type. Both the service and topic use the name of the relay. To change the name of a relay, follow the instructions to change the name of a module.

The following examples are shown without a namespace:

rostopic from the command line

# Shows the state of the relays with a name of 'serno'
rostopic echo /serno

rosservice from the command line

Used to change the state of relays.

# Turning relay 1 on with a name of 'serno'
rosservice call /serno '[{id: 1, state: true}]'
# Turning all relays on with a name of 'serno'
rosservice call /serno '[{id: 0, state: true}]'
# Turning relay 1 on and relay 2 off with a name of 'serno'
rosservice call /serno '[{id: 1, state: true}, {id: 2, state: false}]'