Meaning of ARI LEDs colors and patterns#

There are four different LEDs displays in ARI, located on the ears, the microphone (on the front of the robot) and on the back.

Ears#

Both ears have the same behaviour and the ARI’s ear LEDs have two default meanings:

  1. yellow and red blinking ears mean that battery level is under 20%. For more details check the battery how-to;

  2. blue and red blinking ears mean that an error on the motors occured.

../_images/ARI_ear_LEDs.png

Back LEDs#

The back LEDs have three default meaning:

  1. yellow and red blinking back LEDs mean that the batter level is under 20%. For more details check the battery how-to;

  2. blue and red blinking back LEDs mean that an error on the motors occured;

  3. if ARI is charging, back LEDs show the current charge level.

../_images/ARI_back_LEDs.png

Microphone LEDs#

The microphone LEDs are blue by default.

You can change the microphone LEDs colours yourself: see Tutorial: Creating expressions with LEDs.

../_images/ARI_respeaker_LEDs.png

Example code#

ari_leds_example.py#
 1#!/usr/bin/env python
 2# -*- coding: utf-8 -*-
 3
 4# System imports
 5import rospy
 6from actionlib import SimpleActionClient
 7from pal_device_msgs.msg import DoTimedLedEffectAction, DoTimedLedEffectGoal,
 8LedEffectParams
 9
10
11# led devices ids
12BACK = 0
13LEFT_EAR = 1
14RIGHT_EAR = 2
15RESPEAKER = 4
16
17MAX_PRIORITY = 255  # The maximum value for leds effect priority
18
19
20def init_clients():
21    """ Initializing the action clients. """
22
23    # Creating a client object to communicate
24    # with the LEDs action server
25    led_client = SimpleActionClient("/pal_led_manager/do_effect",
26                                    DoTimedLedEffectAction)
27    led_client.wait_for_server()
28
29    return led_client
30
31
32def show_fixed_color(client,
33                     devices,
34                     r,
35                     g,
36                     b,
37                     a,
38                     duration_secs,
39                     duration_nsecs=0):
40    """ Setting up and sending a LedEffectGoal
41        for a fixed color leds effect
42    """
43    goal = DoTimedLedEffectGoal()
44    goal.devices = devices
45    goal.params.effectType = LedEffectParams.FIXED_COLOR
46
47    # Setting the colour parameters
48    goal.params.fixed_color.color.r = r
49    goal.params.fixed_color.color.g = g
50    goal.params.fixed_color.color.b = b
51    goal.params.fixed_color.color.a = a
52
53    # Setting non effect-specific parameters
54    goal.effectDuration.secs = duration_secs
55    goal.effectDuration.nsecs = duration_nsecs
56    goal.priority = MAX_PRIORITY
57    client.send_goal_and_wait(goal)
58
59
60if __name__ == '__main__':
61   try:
62      rospy.init_node('led_basic_tuto')
63      led_client = init_clients()
64      show_fixed_color(led_client,
65                      [BACK, LEFT_EAR, RIGHT_EAR, RESPEAKER],
66                      r=1,
67                      g=0,
68                      b=0,
69                      a=1,
70                      duration_secs=10)
71   except rospy.ROSInterruptException:
72     print("Abruptly finished!")

Code explanation#

We import the required LEDs-related messages.

ari_leds_example.py#
7from pal_device_msgs.msg import DoTimedLedEffectAction, DoTimedLedEffectGoal,
8LedEffectParams

Then, we define the different LEDs IDs.

ari_leds_example.py#
10# led devices ids
11BACK = 0
12LEFT_EAR = 1
13RIGHT_EAR = 2
14RESPEAKER = 4
15
16MAX_PRIORITY = 255  # The maximum value for leds effect priority

Now, we are defining a set of functions that will be used later in __main__. The first function we implement is init_clients(), to initialise the client-server connection required to interact with the ROS action server involved in the LEDs management.

ari_leds_example.py#
19def init_clients():
20 """ Initializing the action clients. """
21
22 # Creating a client object to communicate
23 # with the LEDs action server
24 led_client = SimpleActionClient("/pal_led_manager/do_effect",
25                                 DoTimedLedEffectAction)
26 led_client.wait_for_server()
27
28 return led_client

We will go through the definition of the function that initialises and sets the fields of a DoTimedLedEffectAction object, that is, the object sent by the node to the action server to request a specific LED effect. In this example, we will see how to set the Fixed Color effect.

ari_leds_example.py#
32def show_fixed_color(client,
33                  devices,
34                  r,
35                  g,
36                  b,
37                  a,
38                  duration_secs,
39                  duration_nsecs=0):
40 """ Setting up and sending a LedEffectGoal
41     for a fixed color leds effect
42 """
43 goal = DoTimedLedEffectGoal()
44 goal.devices = devices
45 goal.params.effectType = LedEffectParams.FIXED_COLOR
46
47 # Setting the colour parameters
48 goal.params.fixed_color.color.r = r
49 goal.params.fixed_color.color.g = g
50 goal.params.fixed_color.color.b = b
51 goal.params.fixed_color.color.a = a
52
53 # Setting non effect-specific parameters
54 goal.effectDuration.secs = duration_secs
55 goal.effectDuration.nsecs = duration_nsecs
56 goal.priority = MAX_PRIORITY
57 client.send_goal_and_wait(goal)

At this point, we have all the functions that we need to run this example. In __main__, we can find how we call the two functions that need it.

ari_leds_example.py#
62if __name__ == '__main__':
63   try:
64      rospy.init_node('led_basic_tuto')
65      print("init")
66      led_client = init_clients()
67      show_fixed_color(led_client,
68                       [BACK, LEFT_EAR, RIGHT_EAR, RESPEAKER],
69                       r=1,
70                       g=0,
71                       b=0,
72                       a=1,
73                       duration_secs=10)
74   except rospy.ROSInterruptException:
75      print("Abruptly finished!")

See also#