3 Robot information release

According to different models, you only need to set the purchased model in [.bashrc], X1(ordinary four-wheel drive) X3(Mike wheel) X3plus(Mike wheel mechanical arm) R2(Ackerman differential) and so on. Section takes X3 as an example

Open the [.bashrc] file

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sudo vim .bashrc 

Find the [ROBOT_TYPE] parameter and modify the corresponding model

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export  ROBOT_TYPE=X3    # ROBOT_TYPE: X1 X3 X3plus R2 X7 

This section takes X3, Mecanum wheeler as an example.

3.1 Node subscription and publishing topics

3.1.1 Function package path:

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~/yahboomcar_ws/src/yahboomcar_bringup 

Functions that ROSMASTER needs to implement: speed control, speed information feedback, battery voltage feedback, buzzer control, running water lamp control.(Note: In the version with a robotic arm, it is also necessary to implement robotic arm control, robotic arm status feedback and PTZ control)

3.2 node data view

3.2.1 Start

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roslaunch yahboomcar_bringup yahboomcar.launch 

3.2.2 View topic list

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rostopic list 

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rosrun  rqt_topic rqt_topic  #Graphically   view the topic 

3.2.3 Program flow chart

3.2.4 Core code(Mcunamu_driver.py)

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Get data(core board -> host computer) 
  edition.data  =  self.car.get_version() 
  battery.data  =  self.car.get_battery_voltage() 
  ax, ay, az  =  self.car.get_accelerometer_data() 
  gx, gy, gz  =  self.car.get_gyroscope_data() 
  mx, my, mz  =  self.car.get_magnetometer_data() 
  vx, vy, angular  =  self.car.get_motion_data() 
Publish data(host computer -> host computer) 
  self.EdiPublisher.publish(edition) 
  self.volPublisher.publish(battery) 
  self.imuPublisher.publish(imu) Note: The imu data here is the combined data of gyroscope and acceleration data 
  self.magPublisher.publish(mag) 
  self.velPublisher.publish(twist) 
Process the acquired data(topic receiving data, transferring data between nodes) 
  cmd_vel_callback(self, msg) 
  RGBLightcallback(self, msg) 
  Buzzercallback(self, msg) 
Publish data(host computer -> core board) 
  self.car.set_car_motion(vx, vy, angular) 
  self.car.set_colorful_effect(msg.data, 6, parm = 1) 
  self.car.set_beep _ self.car.set_beep _ _(1) or _ _ _ _(1) 

3.2.5 Analysis of three callback functions

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    # Water light control, server callback function RGBLight control 
    ''' 
effect=[0, 6], 0: stop light effect, 1: running water light, 2: marquee light, 3: breathing light, 4: gradient light, 5: starlight, 6: battery display 
speed=[1, 10], the smaller the value, the faster the speed changes. 
''' 
    # Car motion control, subscriber callback function 
    ''' 
     vx = msg.linear.x 
     vy = msg.linear.y 
     angular = msg.angular.z 
Note: Because this model is a Mecanum wheel, it can be moved on the y-axis, other models are not applicable 
''' 
    #Buzzer control, subscriber callback function 
    ''' 
self.car.set_beep(1): turn on the buzzer 
self.car.set_beep(0): turn off the buzzer 
''' 

3.2.6 Use rostopic pub command to send running water light control, speed control, buzzer control commands

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Water light control 
rostopic pub /RGBLight std_msgs/Int32 1  # turn on water light
speed control 
rostopic  pub /cmd_vel  geometry_msgs/Twist  "linear: 
  x : 0.0 
  y : 0.0 
  z : 0.0 
angular : 
  x : 0.0 
  y : 0.0 
  z : 0.1 " #The car moves at an angular velocity of 0.1 
Buzzer control 
rostopic pub /Buzzer std_msgs/Bool true  # true  on the buzzer, send false when off 

3.2.7 Use the rostopic echo command to view speed information and battery voltage

speed information 
rostopic echo /cmd_vel 
battery voltage 
rostopic echo /voltage