Beaglebone black Matlab Script

Is there a way to connect and control the beaglebone black with matlab via Serial commands?

I am not looking for Simulink control, but rather direct code control? Does anyone have a script?

Thank you

Answer 1

[Hong Ye]

please check out the examples in http://www.mathworks.com/hardware-support/beaglebone-black.html

Answer 2

[Jorge]

Here are the steps for controlling the BeagleBone Black card from Matlab using a very simple program.

Hardware/Software used:

Windows Platforms: XP and 7 Hardware: BeagleBone Black BBB Operating System: Debian GNU/Linux 7 BeagleBone image: BeagleBone Debian Image 2014-04-23 Matlab version: R2009b g++ compliler. The Linux distributions come with a built-in c-compiler (gcc) and c++ compiler (g++). Example program: myprog from http://inspire.logicsupply.com/2014/07/beaglebone-c-programming-example.html Instructions

First, let’s create a file 'myprog.cpp' in BBB’s root directory using the nano editor (or vim, or emacs - if you prefer) Then, we will connect to the BeagleBone from Matlab and log in as 'root'.

STEP 1- Source Code Example program from elinux.org:

 #include <iostream>
 #include <stdio.h>
 #include <unistd.h>
 using namespace std;

 int main(){
 cout << "LED Flash Start" << endl;
 FILE *LEDHandle = NULL;
 const char *LEDBrightness="/sys/class/leds/beaglebone:green:usr0/brightness";

 for(int i=0; i<3; i++){
  if((LEDHandle = fopen(LEDBrightness, "r+")) != NULL){
   fwrite("1", sizeof(char), 1, LEDHandle);
   fclose(LEDHandle);
  }
  usleep(1000000);

if((LEDHandle = fopen(LEDBrightness, "r+")) != NULL){ fwrite("0", sizeof(char), 1, LEDHandle); fclose(LEDHandle); } usleep(1000000); } cout << "LED Flash End" << endl; }

Program Overview

In this simple example program, we flash the built-in LED USR0 three times. We start out by sending a message to 'cout' (console output) to let us know that the program has started. Finally, a simple message is sent to indicate that we are done is sent to the console.

Step 2 - Compiling: g++ myprog.cpp -o myprog

This command calls the C++ compiler with the source file myprog.cpp and outputs (-o) the file myprog.

STEP 3- Running the Program within the BeagleBone: ./myprog

The program will flash the built-in USR0 LED three times, and display a message at the start and the end:

root@beaglebone:~# ./myprog LED Flash Start LED Flash End

STEP 4- Running the Program Manually from Matlab

Running the program manually in Matlab using basic serial port commands. Create a serial port object for serial port COM5 (check Windows Device Manager to find out the serial port used by the BeagleBone): s=serial('COM5');

Configure the Baudrate to 115,200: set(s,'BaudRate',115200);

 Connect the serial port object to the BeagleBone:
  fopen(s);

Write data to the BeagleBone. Here we log in as root: fprintf(s,'root')

Write data to the BeagleBone. This time execute the program myprog: fprintf(s,'./myprog')

Disconnect and clean up — When you no longer need the serial port object, disconnect it from the device using the fclose function: fclose(s)

Remove the serial port object from memory using the delete function: delete(s)

Remove the serial port object from the MATLAB workspace using the clear command: clear s;

If you encounter any of the messages listed below in Matlab just simply run the following command: delete(instrfind({'Port'},{'COM5'}))

then disconnect the USB cable from the BeagleBone momentarily and then connect it again before continuing.

??? Error using ==> serial.fopen at 72 Port: COM5 is not available. No ports are available. Use INSTRFIND to determine if other instrument objects are connected to the requested device.

Error in ==> LED_tester>LED_tester_OpeningFcn at 77 fopen(s);

Error in ==> gui_mainfcn at 221 feval(gui_State.gui_OpeningFcn, gui_hFigure, [], guidata(gui_hFigure), varargin{:});

Error in ==> LED_tester at 42 gui_mainfcn(gui_State, varargin{:});

This simple example program should help you get started with Matlab controlling the BeagleBone Black where you can go from here.