Gary Servin / ros_lib_melodic

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

Dependencies:   BufferedSerial

Dependents:   rosserial_mbed_hello_world_publisher_melodic Motortest Nucleo_vr_servo_project NucleoFM ... more

ROSSerial_mbed for Melodic 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_melodic

rosserial_mbed Hello World example for Melodic Morenia distribution

Last commit 08 Nov 2019 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();
    }
}

Diff: std_srvs/SetBool.h

Revision:
0:04ac6be8229a
diff -r 000000000000 -r 04ac6be8229a std_srvs/SetBool.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/std_srvs/SetBool.h	Fri Nov 08 14:38:09 2019 -0300
@@ -0,0 +1,123 @@
+#ifndef _ROS_SERVICE_SetBool_h
+#define _ROS_SERVICE_SetBool_h
+#include <stdint.h>
+#include <string.h>
+#include <stdlib.h>
+#include "ros/msg.h"
+
+namespace std_srvs
+{
+
+static const char SETBOOL[] = "std_srvs/SetBool";
+
+  class SetBoolRequest : public ros::Msg
+  {
+    public:
+      typedef bool _data_type;
+      _data_type data;
+
+    SetBoolRequest():
+      data(0)
+    {
+    }
+
+    virtual int serialize(unsigned char *outbuffer) const
+    {
+      int offset = 0;
+      union {
+        bool real;
+        uint8_t base;
+      } u_data;
+      u_data.real = this->data;
+      *(outbuffer + offset + 0) = (u_data.base >> (8 * 0)) & 0xFF;
+      offset += sizeof(this->data);
+      return offset;
+    }
+
+    virtual int deserialize(unsigned char *inbuffer)
+    {
+      int offset = 0;
+      union {
+        bool real;
+        uint8_t base;
+      } u_data;
+      u_data.base = 0;
+      u_data.base |= ((uint8_t) (*(inbuffer + offset + 0))) << (8 * 0);
+      this->data = u_data.real;
+      offset += sizeof(this->data);
+     return offset;
+    }
+
+    const char * getType(){ return SETBOOL; };
+    const char * getMD5(){ return "8b94c1b53db61fb6aed406028ad6332a"; };
+
+  };
+
+  class SetBoolResponse : public ros::Msg
+  {
+    public:
+      typedef bool _success_type;
+      _success_type success;
+      typedef const char* _message_type;
+      _message_type message;
+
+    SetBoolResponse():
+      success(0),
+      message("")
+    {
+    }
+
+    virtual int serialize(unsigned char *outbuffer) const
+    {
+      int offset = 0;
+      union {
+        bool real;
+        uint8_t base;
+      } u_success;
+      u_success.real = this->success;
+      *(outbuffer + offset + 0) = (u_success.base >> (8 * 0)) & 0xFF;
+      offset += sizeof(this->success);
+      uint32_t length_message = strlen(this->message);
+      varToArr(outbuffer + offset, length_message);
+      offset += 4;
+      memcpy(outbuffer + offset, this->message, length_message);
+      offset += length_message;
+      return offset;
+    }
+
+    virtual int deserialize(unsigned char *inbuffer)
+    {
+      int offset = 0;
+      union {
+        bool real;
+        uint8_t base;
+      } u_success;
+      u_success.base = 0;
+      u_success.base |= ((uint8_t) (*(inbuffer + offset + 0))) << (8 * 0);
+      this->success = u_success.real;
+      offset += sizeof(this->success);
+      uint32_t length_message;
+      arrToVar(length_message, (inbuffer + offset));
+      offset += 4;
+      for(unsigned int k= offset; k< offset+length_message; ++k){
+          inbuffer[k-1]=inbuffer[k];
+      }
+      inbuffer[offset+length_message-1]=0;
+      this->message = (char *)(inbuffer + offset-1);
+      offset += length_message;
+     return offset;
+    }
+
+    const char * getType(){ return SETBOOL; };
+    const char * getMD5(){ return "937c9679a518e3a18d831e57125ea522"; };
+
+  };
+
+  class SetBool {
+    public:
+    typedef SetBoolRequest Request;
+    typedef SetBoolResponse Response;
+  };
+
+}
+#endif