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Hi,

I am having trouble making LaserScan run on Arduino. I have modified the c version of the fake laserscan code to run on an Arduino Mega 2560 using Indigo rosserial. I am receiving the error

Unable to sync with device; possible link problem or link software version mismatch such as hydro rosserial_python with groovy Arduino.

I have reinstalled the ros_lib and confirmed other tutorials such as TEMP102 work correctly so I know the basic functionality is OK.

This is my procedure

Terminal 1 -

roscore
  • The ros core starts and run w/o error

Terminal 2

source /opt/ros/indigo/setup.bash
rosrun rosserial_python serial_node.py/dev/ttyACM0

after a few second I see the error as described above.

Here is my Arduino code for the fake laser.

#include "math.h"
#if defined(ARDUINO) && ARDUINO >= 100
#include "Arduino.h"
#else
#include "WProgram.h"
#endif

// ROS includes
#include <ros.h>
#include <ros/time.h>
//#include<std_msgs/Float32.h>
#include <sensor_msgs/LaserScan.h>


sensor_msgs::LaserScan Laser_msg;
ros:: Publisher pub_Laser("LaserData", &Laser_msg);
ros::NodeHandle nh;


double ranges[100];
double Intensities[100];


void setup()
{
  nh.initNode();
  nh.advertise(pub_Laser);


for (int z = 0 ; z<90; z++)
   {
      Laser_msg.ranges[z] = z/3;
      Laser_msg.intensities[z] = z/3;
   }
}


void loop()
{
   Laser_msg.header.stamp = nh.now();
 // Laser_msg.header.frame.id = "laser_frame";
  Laser_msg.angle_min = -1.57;  // start angle of the scan in Radians
  Laser_msg.angle_max = 1.57;  // stop angle of the scan in Radians
  Laser_msg.angle_increment = 0.34;   // angular distance between measurements in Radians 3.14/90
  Laser_msg.time_increment = 4; // seconds between measurements
  Laser_msg.range_min = 0.1;  // min dist in meters
  Laser_msg.range_max = 30;  // max dist in meters


pub_Laser.publish(&Laser_msg);
  nh.spinOnce();
}

any help would be apprciated

Originally posted by charlie on ROS Answers with karma: 36 on 2015-06-24

Post score: 0

1 Answers1

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The rosserial wire protocol is not designed for very large messages. You may want to try publishing a smaller message and transform it into the desired message on the host computer.

Originally posted by ahendrix with karma: 47576 on 2015-06-27

This answer was ACCEPTED on the original site

Post score: 2