autonomy_leds

Firmware and tools to interface with Autonomy Lab's LED strip driver.

Packages

• autonomy_leds_avr: rosserial based firmware for the driver board
• autonomy_leds_msgs: Custom message definitions
• autonomy_leds_tools: High level tools, scripts, udev rules and animation API

Compile instructions

Instructions on how to build the whole stack is provided in autonomy_leds_avr/README.md file. If you do not need to [cross] compile the firmware (i.e. you only need to use the pre-programmed board), follow the same instructions but put an empty .CATKIN_IGNORE file inside autonomy_leds_avr folder after cloning it. That will prevent catkin from [cross] compiling the firmware.

Running the driver

(One time only) Please install provided udev rules in autonomy_leds_tools/udev based on the accompanying README file.

$ rosrun rosserial_python serial_node.py _port:=/dev/led_strip _baud:=115200

Using the low-level API

Setting individual LEDs

To set an individual LED, set the index and color of a message of type autonomy_leds_msgs/LED to your desired values, then publish it to leds/set_led topic.

Changing the values of all LEDs

Messages published to leds/set topic set/manipulate the value of all LEDs in one go. These messages are of type autonomy_leds_msgs/Command. The flag field of this message specifies the desired action:

• flag = 0 (FLAG_SET_ALL) will set the RGB value of each LED based on the color specified by colors_vec vector. Each color is a 16 bit value. The encoding is described in color encoding infomation section.
• flag = 1 (FLAG_CLEAR) clears the LED strip
• flag = 2 (FLAG_SHIFTLEFT) performs a circular shift left on all LEDS
• flag = 3 (FLAG_SHIFTRIGHT) performs a circular shift right on all LEDS
• flag = 4 (FLAG_INVERT) inverts the color of all LEDs

Check autonomy_leds_tools/scripts/test.py file for some demo material.

Color encoding information

Please refer to autonomy_leds_msgs/msg/Command.msg file.

Using the high-level Animation Engine

autonomy_leds_tools package provides a simple Keyframe based animation engine via leds_animation_engine_node. The format for Keyframe messages are defined in autonomy_leds_msgs/msg/Keyframe.msg:

# This array defines the RGB values for each individual LED
# r,g,b should be in [0..1] range, a is ignored
std_msgs/ColorRGBA[] color_pattern

# Number of times the color_pattern should be repeated
# Totoal number of affected LEDs: color_patten.size() * pattern_repeat
uint16 pattern_repeat

# The start index (LED) of this frame
uint16 start_index

# The duration to show this frame
float64 duration

Each Animation (defined in autonomy_leds_msgs/msg/Keyframe.msg), consists of a vector of Keyframes as well as duration and desired timing function of each transition. The engine will co

uint8 TIMING_FUNCTION_LINEAR = 0
uint8 TIMING_FUNCTION_EASE_IN = 1
uint8 TIMING_FUNCTION_EASE_OUT = 2
uint8 TIMING_FUNCTION_EASE_INOUT = 3

# Vector of Keyframes
autonomy_leds_msgs/Keyframe[] keyframes

# Number of iterations, 0 is infinite
uint32 iteration_count

# If set to false, there will be no interpolation between Keyframes 
bool smooth_transition

# The duration of each transition (in seconds)
float64 transition_duration

# Timing function to use (Liear, ease in, ease out, ease in and out)
uint8 timing_function

To display a single Keyframe, publish a message of type autonomy_leds_msg/Keyframe to leds/display topic. To display an Animation, construct a message of type autonomy_leds_msg/Animation, then publish it to leds/animation topic.

To see a demo of these APIs, you can check autonomy_leds_tools/scripts/test_anim.py script.

Run Everything (driver + high level engine)

$ roslaunch autonomy_leds_tools engine.launch