how to increase rosserial buffer size

edit

I found this thread a bit hard to follow, but managed to figure out how to fix the problem. This is assuming you have the same error when using nav_msgs/odometry.

Wherever your Arduino libraries are located, there should be a folder for your ROS libraries. When you first installed ROS, it was named 'ros_lib', In this folder, you'll find 'ros.h', as well as 'node_handle.h' in a folder called 'ros'.

[Arduino Libraries] ---> ros_lib ---> ros.h

[Arduino Libraries] ---> ros_lib ---> ros ---> node_handle.h

The relevant portion of the ros.h file looks like:

#ifndef _ROS_H_
#define _ROS_H_

#include "ros/node_handle.h"
#include "ArduinoHardware.h"

namespace ros
{
#if defined(__AVR_ATmega8__) || defined(__AVR_ATmega168__)
  /* downsize our buffers */
  typedef NodeHandle_<ArduinoHardware, 6, 6, 150, 150> NodeHandle;

#elif defined(__AVR_ATmega328P__)

  typedef NodeHandle_<ArduinoHardware, 25, 25, 280, 280> NodeHandle;

#else

  typedef NodeHandle_<ArduinoHardware> NodeHandle;

#endif   
}

#endif

Assuming you're using the Atmega2560, you can paste this between the #elif and #else. The numbers define in order [MAX_SUBSCRIBERS, MAX_PUBLISHERS, INPUT_SIZE, OUTPUT_SIZE].

#elif defined(__AVR_ATmega2560__)

  typedef NodeHandle_<ArduinoHardware, 15, 15, 512, 1024> NodeHandle;

I believe this method was the proper place to change the buffer sizes, as mentioned by fergs.

An alternative solution is to alter node_handle.h instead. It seems like this is what the OP dan ended up doing.

The relevant portion of the node_handle.h file looks like:

namespace ros {

  using rosserial_msgs::TopicInfo;

  /* Node Handle */
  template<class Hardware,
           int MAX_SUBSCRIBERS=25,
           int MAX_PUBLISHERS=25,
           int INPUT_SIZE=512,
           int OUTPUT_SIZE=512>
  class NodeHandle_ : public NodeHandleBase_
  {

Here, you can change the OUTPUT_SIZE from 512 to 1024. I personally had to decrease MAX_SUBSCRIBERS and MAX_PUBLISHERS and publishers from 25 to 15, otherwise my rosserial node wouldn't work.

After doing this, save the file you editted and recompile/upload your Arduino code, and it should eliminate the buffer size error from using nav_msgs/odometry.

What board are you using? 512 is the default for the ATmega2650 and ATmega1280. If you want to increase it for these boards, define it in the ros.h according to which board you are using.