LEDs API#

Overview#

ARI has 4 led displaying devices capable of being controlled via our ROS interface:

Back ring: a LED ring at the back, below the emergency button, with a
variety of colour options.
Ears rings: LED ring in each of its ears with a variety of colour
options.
ReSpeaker: LED ring at the speaker.

	ID	#Leds	Available Effects
Back	0	40	All
Ear Left	1	16	All
Ear Right	2	16	All
ReSpeaker	4	12	Fixed Color

Different devices may have different capabilities, and may only be able to show part of the effects.

LED Manager API#

All led devices are controlled using the same ROS Interface, provided by the PAL Led Manager. This interface allows clients to send effects to one or multiple led devices, for a duration of time and a priority. When a device has more than one effect active at a time, it displays the one with the highest priority, until the duration ends and then displays the next effect with the highest priority. There’s a default effect with unlimited duration and lowest priority that displays a fixed color.

Interface#

The led interface is an Action Server: /pal_led_manager/do_effect

A goal consists of:

devices A list of devices the goal applies to.
params The effect type, and the parameters for the selected effect type.
effectDuration Duration of the effect, when the time is over the previous
effect will be restored. 0 will make it display forever
priority Priority of the effect, 0 is no priority, 255 is max priority

List of LED effects#

Effects	ID
Set colour	0
Rainbow	1
Fade	2
Blink	3
Progress	4
Flow	5
Pre-programmed effect	6

The different effects and parameters are listed in the pal_device_msgs/msg