Control RGB Light

For convenient control, the underlying software of the robotic arm expansion board is developed separately and provides interface calls for controlling bus servos, PWM servos, and RGB lights. The relevant underlying driver source code has been packaged into a Python library, which is already installed in the factory image. If you want to port it to your own system, you can find the Dofbot.zip compressed package in the program source code summary folder.

Extract the compressed package: You need to copy the compressed package into Docker for extraction. Since basic control does not involve ROS, users can also install it on the host machine.

unzip Dofbot.zip 

Install Python driver library: This is just a demonstration of how to install the Python driver library

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cd Dofbot/0.py_install && sudo python3 setup.py install

After entering the user password and pressing Enter to confirm, if you see the installation prompt Arm_Lib=x.x.x version number, it means the installation was successful.

I. API Introduction

The corresponding API for RGB light is: Arm_RGB_set(R, G, B)

Function: Set the color of the RGB light.

Parameter explanation:

R: Control the brightness of the red color in the RGB light, range is 0-255, the larger the value, the brighter the light.

G: Control the brightness of the green color in the RGB light, range is 0-255, the larger the value, the brighter the light.

B: Control the brightness of the blue color in the RGB light, range is 0-255, the larger the value, the brighter the light.

Return value: None.

II. Start Docker

After entering the main board desktop, open a terminal and run the following command to start the corresponding Dofbot container:

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./Docker_Ros.sh

Then enter the following command in the Docker terminal to start jupyter-lab,

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cd
jupyter-lab --allow-root

Then enter the main board's IP address followed by :9999 in the browser

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IP:9999         // Example: 192.168.1.11:9999

III. Code Content

Code path: /root/Dofbot/3.ctrl_Arm/1.rgb.ipynb

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Loop to make the RGB light on the robotic arm expansion board light up red, green, and blue.
#!/usr/bin/env python3
#coding=utf-8
import time
from Arm_Lib import Arm_Device
# Get the robotic arm object
Arm = Arm_Device()
time.sleep(.1)
def main():
     while True:
     Arm.Arm_RGB_set(50, 0, 0) #RGB lights up red
     time.sleep(.5)
     Arm.Arm_RGB_set(0, 50, 0) #RGB lights up green
     time.sleep(.5)
     Arm.Arm_RGB_set(0, 0, 50) #RGB lights up blue
     time.sleep(.5)
     print(" END OF LINE! ")
try :
     main()
except KeyboardInterrupt:
     # Release Arm object
     del Arm
     print(" Program closed! ")
     pass
​

Open the 1.rgb.ipynb file from jupyter lab, and click the "run entire notebook" button on the jupyter lab toolbar, you will see the RGB light on the robotic arm expansion board cycle through red, green, and blue colors every 0.5 seconds.

To exit, click the stop button on the toolbar.