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

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();
    }
}
Committer:
garyservin
Date:
Thu Mar 31 14:22:59 2016 +0000
Revision:
0:fd24f7ca9688
Initial commit, generated based on a clean indigo-desktop-full

Who changed what in which revision?

UserRevisionLine numberNew contents of line
garyservin 0:fd24f7ca9688 1 #ifndef _ROS_opencv_apps_FaceArray_h
garyservin 0:fd24f7ca9688 2 #define _ROS_opencv_apps_FaceArray_h
garyservin 0:fd24f7ca9688 3
garyservin 0:fd24f7ca9688 4 #include <stdint.h>
garyservin 0:fd24f7ca9688 5 #include <string.h>
garyservin 0:fd24f7ca9688 6 #include <stdlib.h>
garyservin 0:fd24f7ca9688 7 #include "ros/msg.h"
garyservin 0:fd24f7ca9688 8 #include "opencv_apps/Face.h"
garyservin 0:fd24f7ca9688 9
garyservin 0:fd24f7ca9688 10 namespace opencv_apps
garyservin 0:fd24f7ca9688 11 {
garyservin 0:fd24f7ca9688 12
garyservin 0:fd24f7ca9688 13 class FaceArray : public ros::Msg
garyservin 0:fd24f7ca9688 14 {
garyservin 0:fd24f7ca9688 15 public:
garyservin 0:fd24f7ca9688 16 uint8_t faces_length;
garyservin 0:fd24f7ca9688 17 opencv_apps::Face st_faces;
garyservin 0:fd24f7ca9688 18 opencv_apps::Face * faces;
garyservin 0:fd24f7ca9688 19
garyservin 0:fd24f7ca9688 20 FaceArray():
garyservin 0:fd24f7ca9688 21 faces_length(0), faces(NULL)
garyservin 0:fd24f7ca9688 22 {
garyservin 0:fd24f7ca9688 23 }
garyservin 0:fd24f7ca9688 24
garyservin 0:fd24f7ca9688 25 virtual int serialize(unsigned char *outbuffer) const
garyservin 0:fd24f7ca9688 26 {
garyservin 0:fd24f7ca9688 27 int offset = 0;
garyservin 0:fd24f7ca9688 28 *(outbuffer + offset++) = faces_length;
garyservin 0:fd24f7ca9688 29 *(outbuffer + offset++) = 0;
garyservin 0:fd24f7ca9688 30 *(outbuffer + offset++) = 0;
garyservin 0:fd24f7ca9688 31 *(outbuffer + offset++) = 0;
garyservin 0:fd24f7ca9688 32 for( uint8_t i = 0; i < faces_length; i++){
garyservin 0:fd24f7ca9688 33 offset += this->faces[i].serialize(outbuffer + offset);
garyservin 0:fd24f7ca9688 34 }
garyservin 0:fd24f7ca9688 35 return offset;
garyservin 0:fd24f7ca9688 36 }
garyservin 0:fd24f7ca9688 37
garyservin 0:fd24f7ca9688 38 virtual int deserialize(unsigned char *inbuffer)
garyservin 0:fd24f7ca9688 39 {
garyservin 0:fd24f7ca9688 40 int offset = 0;
garyservin 0:fd24f7ca9688 41 uint8_t faces_lengthT = *(inbuffer + offset++);
garyservin 0:fd24f7ca9688 42 if(faces_lengthT > faces_length)
garyservin 0:fd24f7ca9688 43 this->faces = (opencv_apps::Face*)realloc(this->faces, faces_lengthT * sizeof(opencv_apps::Face));
garyservin 0:fd24f7ca9688 44 offset += 3;
garyservin 0:fd24f7ca9688 45 faces_length = faces_lengthT;
garyservin 0:fd24f7ca9688 46 for( uint8_t i = 0; i < faces_length; i++){
garyservin 0:fd24f7ca9688 47 offset += this->st_faces.deserialize(inbuffer + offset);
garyservin 0:fd24f7ca9688 48 memcpy( &(this->faces[i]), &(this->st_faces), sizeof(opencv_apps::Face));
garyservin 0:fd24f7ca9688 49 }
garyservin 0:fd24f7ca9688 50 return offset;
garyservin 0:fd24f7ca9688 51 }
garyservin 0:fd24f7ca9688 52
garyservin 0:fd24f7ca9688 53 const char * getType(){ return "opencv_apps/FaceArray"; };
garyservin 0:fd24f7ca9688 54 const char * getMD5(){ return "40b464276ad8e3c5012f7a3a93eed2a4"; };
garyservin 0:fd24f7ca9688 55
garyservin 0:fd24f7ca9688 56 };
garyservin 0:fd24f7ca9688 57
garyservin 0:fd24f7ca9688 58 }
garyservin 0:fd24f7ca9688 59 #endif