Ruediger

Ruediger is the name of my Robot. It is design to adapt the platform of the Makeblock robots to communicate with ROS

For this we will use the Arduino board from Makeblock : MegaPi and a Raspberry Pi

The aim is to control the Robot over ROS and to get all the information about the sensors over the Arduino

That is why there will be 2 folders

• arduino_ruediger
• raspi_ruediger

To build the Robot, I used the instructions of the Ultimate Robot 2.0 Detect Robot You can watch them there : https://www.youtube.com/watch?v=8k3qfqbZZQA&ab_channel=Makeblock

For the cabling I used the following connections:

Slot	Motor
SLOT_1	25 mm DC Encoder Motor 9V/ 86RPM (Motor A)
SLOT_2	25 mm DC Encoder Motor 9V/185RPM (Motor B)
SLOT_3	25 mm DC Encoder Motor 9V/185RPM (Motor C)
SLOT_4	Makeblock Gripper

Port	Sensor
PORT_5	No Sensor
SLOT_6	IMU
SLOT_7	Ultrasonic Sensor
SLOT_8	No Sensor

Arduino_Ruediger

The Arduino part is there to gather all the sensors information and to move the Robot

What it can so far:

• Get data from the Makeblock Ultrason

• Get data from the Makeblock Inertial Motion Unit

• Get data from the Motor Encoders

• Move the Makeblock Motors

• Communicate over ROS Serial to a ROS Master

I used Platform IO combined to Visual Studio Code for ease of development please feel free to use whatever suits you most

Raspi_Ruediger

The Raspberry Pi is setted up with ROS and comminicates with Arduino over serial

Best Practices

Use ubiquity

For ease of use, I decided to use the image from [Ubiquity]!https://downloads.ubiquityrobotics.com/pi.html

I can only highly recommand reading and following those tips : https://github.com/UbiquityRobotics/ubiquity_launches

Use VS Code / VS Code Insider

Develop over SSH with Visual Studio Code

https://www.hanselman.com/blog/VisualStudioCodeRemoteDevelopmentOverSSHToARaspberryPiIsButter.aspx https://code.visualstudio.com/docs/remote/troubleshooting#_configuring-key-based-authentication

Connect with ROS on a 3rd Computer

Use a Linux Computer with ROS installed - I use Ubuntu 16.04

Set up Ubuntu to connect to the Wifi of the the Robot Export ROS_MASTER_URI to connect to the ROS of the Robot - you can also add it to your bashrc

export ROS_MASTER_URI=http://ruediger.local:11311
export ROS_IP=<your_ip_address_on_wifi> # export ROS_IP=10.42.0.130

Use Teleop to command the Robot

git clone git@github.com:ros-teleop/teleop_twist_keyboard.git
cd teleop_twist_keyboard
. devel/setup.bash
rosrun teleop_twist_keyboard teleop_twist_keyboard.py cmd_vel:=/serial/cmd_vel _key_timeout:=0.6

Command the Motor_1 and Motor_4

rostopic pub /serial/cmd_mot1 std_msgs/Int32 int 'data: 40'
rostopic pub /serial/cmd_mot4 std_msgs/Int32 int 'data: -40'