Gary Servin / ros_lib_indigo

ROS Serial library for Mbed platforms for ROS Indigo Igloo. Check http://wiki.ros.org/rosserial_mbed/ for more information

Dependencies:   BufferedSerial

Dependents:   rosserial_mbed_hello_world_publisher rtos_base_control rosserial_mbed_F64MA ROS-RTOS ... more

ROSSerial_mbed for Indigo Distribution

The Robot Operating System (ROS) is a flexible framework for writing robot software. It is a collection of tools, libraries, and conventions that aim to simplify the task of creating complex and robust robot behavior across a wide variety of robotic platforms.

The rosserial_mbed package allows to write ROS nodes on any mbed enabled devices and have them connected to a running ROS system on your computer using the serial port.

Hello World (example publisher)

Import programrosserial_mbed_hello_world_publisher

rosserial_mbed Hello World

Last commit 19 Apr 2016 by Gary Servin

Running the Code

Now, launch the roscore in a new terminal window:

Quote:

$ roscore

Next, run the rosserial client application that forwards your MBED messages to the rest of ROS. Make sure to use the correct serial port:

Quote:

$ rosrun rosserial_python serial_node.py /dev/ttyACM0

Finally, watch the greetings come in from your MBED by launching a new terminal window and entering :

Quote:

$ rostopic echo chatter

See Also

More examples

Blink

/*
 * rosserial Subscriber Example
 * Blinks an LED on callback
 */
#include "mbed.h"
#include <ros.h>
#include <std_msgs/Empty.h>

ros::NodeHandle nh;
DigitalOut myled(LED1);

void messageCb(const std_msgs::Empty& toggle_msg){
    myled = !myled;   // blink the led
}

ros::Subscriber<std_msgs::Empty> sub("toggle_led", &messageCb);

int main() {
    nh.initNode();
    nh.subscribe(sub);

    while (1) {
        nh.spinOnce();
        wait_ms(1);
    }
}

Push

/*
 * Button Example for Rosserial
 */

#include "mbed.h"
#include <ros.h>
#include <std_msgs/Bool.h>

PinName button = p20;

ros::NodeHandle nh;

std_msgs::Bool pushed_msg;
ros::Publisher pub_button("pushed", &pushed_msg);

DigitalIn button_pin(button);
DigitalOut led_pin(LED1);

bool last_reading;
long last_debounce_time=0;
long debounce_delay=50;
bool published = true;

Timer t;
int main() {
    t.start();
    nh.initNode();
    nh.advertise(pub_button);

    //Enable the pullup resistor on the button
    button_pin.mode(PullUp);

    //The button is a normally button
    last_reading = ! button_pin;

    while (1) {
        bool reading = ! button_pin;

        if (last_reading!= reading) {
            last_debounce_time = t.read_ms();
            published = false;
        }

        //if the button value has not changed for the debounce delay, we know its stable
        if ( !published && (t.read_ms() - last_debounce_time)  > debounce_delay) {
            led_pin = reading;
            pushed_msg.data = reading;
            pub_button.publish(&pushed_msg);
            published = true;
        }

        last_reading = reading;

        nh.spinOnce();
    }
}

ros/subscriber.h

Committer:
garyservin
Date:
2016-03-31
Revision:
0:fd24f7ca9688

File content as of revision 0:fd24f7ca9688:

/* 
 * Software License Agreement (BSD License)
 *
 * Copyright (c) 2011, Willow Garage, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above
 *    copyright notice, this list of conditions and the following
 *    disclaimer in the documentation and/or other materials provided
 *    with the distribution.
 *  * Neither the name of Willow Garage, Inc. nor the names of its
 *    contributors may be used to endorse or promote prducts derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef ROS_SUBSCRIBER_H_
#define ROS_SUBSCRIBER_H_

#include "rosserial_msgs/TopicInfo.h"

namespace ros {

  /* Base class for objects subscribers. */
  class Subscriber_
  {
    public:
      virtual void callback(unsigned char *data)=0;
      virtual int getEndpointType()=0;

      // id_ is set by NodeHandle when we advertise 
      int id_;

      virtual const char * getMsgType()=0;
      virtual const char * getMsgMD5()=0;
      const char * topic_;
  };


  /* Actual subscriber, templated on message type. */
  template<typename MsgT>
  class Subscriber: public Subscriber_{
    public:
      typedef void(*CallbackT)(const MsgT&);
      MsgT msg;

      Subscriber(const char * topic_name, CallbackT cb, int endpoint=rosserial_msgs::TopicInfo::ID_SUBSCRIBER) :
        cb_(cb),
        endpoint_(endpoint)
      {
        topic_ = topic_name;
      };

      virtual void callback(unsigned char* data){
        msg.deserialize(data);
        this->cb_(msg);
      }

      virtual const char * getMsgType(){ return this->msg.getType(); }
      virtual const char * getMsgMD5(){ return this->msg.getMD5(); }
      virtual int getEndpointType(){ return endpoint_; }

    private:
      CallbackT cb_;
      int endpoint_;
  };

}

#endif