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: rosserial_msgs/RequestParam.h

Revision:
0:04ac6be8229a
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rosserial_msgs/RequestParam.h	Fri Nov 08 14:38:09 2019 -0300
@@ -0,0 +1,212 @@
+#ifndef _ROS_SERVICE_RequestParam_h
+#define _ROS_SERVICE_RequestParam_h
+#include <stdint.h>
+#include <string.h>
+#include <stdlib.h>
+#include "ros/msg.h"
+
+namespace rosserial_msgs
+{
+
+static const char REQUESTPARAM[] = "rosserial_msgs/RequestParam";
+
+  class RequestParamRequest : public ros::Msg
+  {
+    public:
+      typedef const char* _name_type;
+      _name_type name;
+
+    RequestParamRequest():
+      name("")
+    {
+    }
+
+    virtual int serialize(unsigned char *outbuffer) const
+    {
+      int offset = 0;
+      uint32_t length_name = strlen(this->name);
+      varToArr(outbuffer + offset, length_name);
+      offset += 4;
+      memcpy(outbuffer + offset, this->name, length_name);
+      offset += length_name;
+      return offset;
+    }
+
+    virtual int deserialize(unsigned char *inbuffer)
+    {
+      int offset = 0;
+      uint32_t length_name;
+      arrToVar(length_name, (inbuffer + offset));
+      offset += 4;
+      for(unsigned int k= offset; k< offset+length_name; ++k){
+          inbuffer[k-1]=inbuffer[k];
+      }
+      inbuffer[offset+length_name-1]=0;
+      this->name = (char *)(inbuffer + offset-1);
+      offset += length_name;
+     return offset;
+    }
+
+    const char * getType(){ return REQUESTPARAM; };
+    const char * getMD5(){ return "c1f3d28f1b044c871e6eff2e9fc3c667"; };
+
+  };
+
+  class RequestParamResponse : public ros::Msg
+  {
+    public:
+      uint32_t ints_length;
+      typedef int32_t _ints_type;
+      _ints_type st_ints;
+      _ints_type * ints;
+      uint32_t floats_length;
+      typedef float _floats_type;
+      _floats_type st_floats;
+      _floats_type * floats;
+      uint32_t strings_length;
+      typedef char* _strings_type;
+      _strings_type st_strings;
+      _strings_type * strings;
+
+    RequestParamResponse():
+      ints_length(0), ints(NULL),
+      floats_length(0), floats(NULL),
+      strings_length(0), strings(NULL)
+    {
+    }
+
+    virtual int serialize(unsigned char *outbuffer) const
+    {
+      int offset = 0;
+      *(outbuffer + offset + 0) = (this->ints_length >> (8 * 0)) & 0xFF;
+      *(outbuffer + offset + 1) = (this->ints_length >> (8 * 1)) & 0xFF;
+      *(outbuffer + offset + 2) = (this->ints_length >> (8 * 2)) & 0xFF;
+      *(outbuffer + offset + 3) = (this->ints_length >> (8 * 3)) & 0xFF;
+      offset += sizeof(this->ints_length);
+      for( uint32_t i = 0; i < ints_length; i++){
+      union {
+        int32_t real;
+        uint32_t base;
+      } u_intsi;
+      u_intsi.real = this->ints[i];
+      *(outbuffer + offset + 0) = (u_intsi.base >> (8 * 0)) & 0xFF;
+      *(outbuffer + offset + 1) = (u_intsi.base >> (8 * 1)) & 0xFF;
+      *(outbuffer + offset + 2) = (u_intsi.base >> (8 * 2)) & 0xFF;
+      *(outbuffer + offset + 3) = (u_intsi.base >> (8 * 3)) & 0xFF;
+      offset += sizeof(this->ints[i]);
+      }
+      *(outbuffer + offset + 0) = (this->floats_length >> (8 * 0)) & 0xFF;
+      *(outbuffer + offset + 1) = (this->floats_length >> (8 * 1)) & 0xFF;
+      *(outbuffer + offset + 2) = (this->floats_length >> (8 * 2)) & 0xFF;
+      *(outbuffer + offset + 3) = (this->floats_length >> (8 * 3)) & 0xFF;
+      offset += sizeof(this->floats_length);
+      for( uint32_t i = 0; i < floats_length; i++){
+      union {
+        float real;
+        uint32_t base;
+      } u_floatsi;
+      u_floatsi.real = this->floats[i];
+      *(outbuffer + offset + 0) = (u_floatsi.base >> (8 * 0)) & 0xFF;
+      *(outbuffer + offset + 1) = (u_floatsi.base >> (8 * 1)) & 0xFF;
+      *(outbuffer + offset + 2) = (u_floatsi.base >> (8 * 2)) & 0xFF;
+      *(outbuffer + offset + 3) = (u_floatsi.base >> (8 * 3)) & 0xFF;
+      offset += sizeof(this->floats[i]);
+      }
+      *(outbuffer + offset + 0) = (this->strings_length >> (8 * 0)) & 0xFF;
+      *(outbuffer + offset + 1) = (this->strings_length >> (8 * 1)) & 0xFF;
+      *(outbuffer + offset + 2) = (this->strings_length >> (8 * 2)) & 0xFF;
+      *(outbuffer + offset + 3) = (this->strings_length >> (8 * 3)) & 0xFF;
+      offset += sizeof(this->strings_length);
+      for( uint32_t i = 0; i < strings_length; i++){
+      uint32_t length_stringsi = strlen(this->strings[i]);
+      varToArr(outbuffer + offset, length_stringsi);
+      offset += 4;
+      memcpy(outbuffer + offset, this->strings[i], length_stringsi);
+      offset += length_stringsi;
+      }
+      return offset;
+    }
+
+    virtual int deserialize(unsigned char *inbuffer)
+    {
+      int offset = 0;
+      uint32_t ints_lengthT = ((uint32_t) (*(inbuffer + offset))); 
+      ints_lengthT |= ((uint32_t) (*(inbuffer + offset + 1))) << (8 * 1); 
+      ints_lengthT |= ((uint32_t) (*(inbuffer + offset + 2))) << (8 * 2); 
+      ints_lengthT |= ((uint32_t) (*(inbuffer + offset + 3))) << (8 * 3); 
+      offset += sizeof(this->ints_length);
+      if(ints_lengthT > ints_length)
+        this->ints = (int32_t*)realloc(this->ints, ints_lengthT * sizeof(int32_t));
+      ints_length = ints_lengthT;
+      for( uint32_t i = 0; i < ints_length; i++){
+      union {
+        int32_t real;
+        uint32_t base;
+      } u_st_ints;
+      u_st_ints.base = 0;
+      u_st_ints.base |= ((uint32_t) (*(inbuffer + offset + 0))) << (8 * 0);
+      u_st_ints.base |= ((uint32_t) (*(inbuffer + offset + 1))) << (8 * 1);
+      u_st_ints.base |= ((uint32_t) (*(inbuffer + offset + 2))) << (8 * 2);
+      u_st_ints.base |= ((uint32_t) (*(inbuffer + offset + 3))) << (8 * 3);
+      this->st_ints = u_st_ints.real;
+      offset += sizeof(this->st_ints);
+        memcpy( &(this->ints[i]), &(this->st_ints), sizeof(int32_t));
+      }
+      uint32_t floats_lengthT = ((uint32_t) (*(inbuffer + offset))); 
+      floats_lengthT |= ((uint32_t) (*(inbuffer + offset + 1))) << (8 * 1); 
+      floats_lengthT |= ((uint32_t) (*(inbuffer + offset + 2))) << (8 * 2); 
+      floats_lengthT |= ((uint32_t) (*(inbuffer + offset + 3))) << (8 * 3); 
+      offset += sizeof(this->floats_length);
+      if(floats_lengthT > floats_length)
+        this->floats = (float*)realloc(this->floats, floats_lengthT * sizeof(float));
+      floats_length = floats_lengthT;
+      for( uint32_t i = 0; i < floats_length; i++){
+      union {
+        float real;
+        uint32_t base;
+      } u_st_floats;
+      u_st_floats.base = 0;
+      u_st_floats.base |= ((uint32_t) (*(inbuffer + offset + 0))) << (8 * 0);
+      u_st_floats.base |= ((uint32_t) (*(inbuffer + offset + 1))) << (8 * 1);
+      u_st_floats.base |= ((uint32_t) (*(inbuffer + offset + 2))) << (8 * 2);
+      u_st_floats.base |= ((uint32_t) (*(inbuffer + offset + 3))) << (8 * 3);
+      this->st_floats = u_st_floats.real;
+      offset += sizeof(this->st_floats);
+        memcpy( &(this->floats[i]), &(this->st_floats), sizeof(float));
+      }
+      uint32_t strings_lengthT = ((uint32_t) (*(inbuffer + offset))); 
+      strings_lengthT |= ((uint32_t) (*(inbuffer + offset + 1))) << (8 * 1); 
+      strings_lengthT |= ((uint32_t) (*(inbuffer + offset + 2))) << (8 * 2); 
+      strings_lengthT |= ((uint32_t) (*(inbuffer + offset + 3))) << (8 * 3); 
+      offset += sizeof(this->strings_length);
+      if(strings_lengthT > strings_length)
+        this->strings = (char**)realloc(this->strings, strings_lengthT * sizeof(char*));
+      strings_length = strings_lengthT;
+      for( uint32_t i = 0; i < strings_length; i++){
+      uint32_t length_st_strings;
+      arrToVar(length_st_strings, (inbuffer + offset));
+      offset += 4;
+      for(unsigned int k= offset; k< offset+length_st_strings; ++k){
+          inbuffer[k-1]=inbuffer[k];
+      }
+      inbuffer[offset+length_st_strings-1]=0;
+      this->st_strings = (char *)(inbuffer + offset-1);
+      offset += length_st_strings;
+        memcpy( &(this->strings[i]), &(this->st_strings), sizeof(char*));
+      }
+     return offset;
+    }
+
+    const char * getType(){ return REQUESTPARAM; };
+    const char * getMD5(){ return "9f0e98bda65981986ddf53afa7a40e49"; };
+
+  };
+
+  class RequestParam {
+    public:
+    typedef RequestParamRequest Request;
+    typedef RequestParamResponse Response;
+  };
+
+}
+#endif