Gary Servin / ros_lib_kinetic

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

Dependencies:   BufferedSerial

Dependents:   rosserial_mbed_hello_world_publisher_kinetic s-rov-firmware ROS_HCSR04 DISCO-F469NI_LCDTS_demo ... more

ROSSerial_mbed for Kinetic 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_kinetic

rosserial_mbed Hello World example for Kinetic Kame distribution

Last commit 31 Dec 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();
    }
}

Files at this revision

API Documentation at this revision

Revision 1:a849bf78d77f, committed 2016-12-31

Comitter:
garyservin
Date:
Sat Dec 31 00:59:58 2016 +0000
Parent:
0:9e9b7db60fd5
Commit message:
Add missing round() method

Changed in this revision

ros/duration.h Show annotated file Show diff for this revision Revisions of this file
ros/time.h Show annotated file Show diff for this revision Revisions of this file 
diff -r 9e9b7db60fd5 -r a849bf78d77f ros/duration.h
--- a/ros/duration.h	Sat Dec 31 00:48:34 2016 +0000
+++ b/ros/duration.h	Sat Dec 31 00:59:58 2016 +0000
@@ -53,6 +53,7 @@
         normalizeSecNSecSigned(sec, nsec);
       }
 
+      double round(double number) { return number < 0.0 ? ceil(number - 0.5): floor(number + 0.5); }
       double toSec() const { return (double)sec + 1e-9*(double)nsec; };
       void fromSec(double t) { sec = (uint32_t) floor(t); nsec = (uint32_t) round((t-sec) * 1e9); };
 

diff -r 9e9b7db60fd5 -r a849bf78d77f ros/time.h
--- a/ros/time.h	Sat Dec 31 00:48:34 2016 +0000
+++ b/ros/time.h	Sat Dec 31 00:59:58 2016 +0000
@@ -54,6 +54,7 @@
         normalizeSecNSec(sec, nsec);
       }
 
+      double round(double number) { return number < 0.0 ? ceil(number - 0.5): floor(number + 0.5); }
       double toSec() const { return (double)sec + 1e-9*(double)nsec; };
       void fromSec(double t) { sec = (uint32_t) floor(t); nsec = (uint32_t) round((t-sec) * 1e9); };