README: /ros_lcd_driver/

ROS1 repository in the https://github.com/Pet-Series Git-Organizations.

• Containing a ROS1-package.
  
• For a ROS2 package, please visit https://github.com/Pet-Series/pet_ros2_lcd_pkg

What is this folder for?

ROS1-package that publish text, via ROS1-topics, on an physical I2C-Display.
This packages also contains a ROS1 test publisher.

Display any string on the LCD-Display via ROS1-topics. * ROS1-topic `lcd_display/row1` => LCD-display row1 * ROS1-topic `lcd_display/row2` => LCD-display row2

flowchart LR
    A(topic: lcd_display/row1)-->|Subscribe| C[node: Ros_lcd_node]
    B(topic: lcd_display/row1)-->|Subscribe| C
    C -->|i2c| D[hardware: LCD1602 display]

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How do I set up the Hardware?

• Hardware: Display LCD1602A (LCD2040) LCD Display - 16x2 Character LCD Backlight.
• Hardware: I²C interface PC8574T - Piggyback on the backisde of the display.
  
  • Software: Pyhton library "from rpi_lcd import LCD" that supports LCD text displays (20x4, 16x2 and other) via the I²C converter.
    

    $ pip install rpi-lcd
    

    Display LCD1602A with I²C interface PC8574T

• Hardware: I²C wire between the PC8574T and the Raspberry Pi.
• Hardware: Raspberry Pi (aka. Target System)
  • Operating system: Linux/Raspian Buster (based on Debian 10)
  • Middleware: ROS 1.0 Melodic

How do I set up the ROS1-package?

$ cd <your ROS-workspace>
$ git clone https://github.com/Pet-Series/ros_lcd_driver.git
$ catkin build ros_lcd_driver

How do I launch the ROS1-package?

1. Launch main ROS-system (on the Target System)

   $ roscore
   

2. Launch the the LCD-display-driver-node (on the Target System)
   There is two ways to launch the LCD-display-driver-node-subscriber (select ONE of them)

   1. Launch alternative: Via a launch file (recommended)

      $ roslaunch ros_lcd_driver ros_lcd_driver.launch
      

      Note:warning: By using the .launch file you could <remap> existing topic-names to the generic topic-names used in this implementation.

   2. Launch alternative: Direct launch the python node.

      $ rosrun ros_lcd_driver lcd_driver_node.py
      

How do I verify that everythings is OK?

These steps are only for verification and not necessary.

3. Make sure that the node/topics is up and running.

   $ rostopic list
       /lcd_display/row1
       /lcd_display/row2
   

4. Investigate the node/topics.

   $ rostopic info /lcd_display/row1
       Type: std_msgs/String
       Publishers: None
       Subscribers: /lcd_display
   
   $ rosmsg show std_msgs/String
       string data
   

How do I publish text on the Display?

Publish your first message on the display

5. "Manually" via command line:

   $ rostopic pub /lcd_display/row1 std_msgs/String "data: 'Hello LCD World'"
   

6. Via provided test publisher:

   $ rosrun ros_lcd_driver test_publisher.py
   

   row1 = current date-time. Example: 11 Mar 19:20:36
   row2 = seconds since start. Example: Run 56.00 Sec

Whats next?

Modify, the provided test publisher, or create your own publisher to suit your needs.

Who do I talk to?

• Repo. owner: "SeniorKullken" stefan.kull@gmail.com
• Folder contributor: "Kullken" karl.viktor.kull@gmail.com

⚠️Be aware⚠️ You might get some "close to hardware experiences".