Difference between revisions of "Hello World"

Revision as of 17:34, 17 May 2016

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Introduction

This article is about the Hello World program, which is used to show the compilation and upload steps of a simple program on a Tmote Sky.

You will learn

This tutorial teaches you how to compile a program on Contiki OS and also the most basic syntax of programming in ContikiOS.

Step 1

Open the terminal window.

Step 2

In the terminal window, go to the hello world example folder.

.cd /examples/hello-world

Step 3

Compile the code for the native platform (to be used when no mote is connected to the laptop.)

make TARGET=native

If there is any bug during compilation which says "#include<curses.h> : No such file or directory" you need to do the following on Ubuntu.

If you are currently in the terminal, type "sudo apt-get install libncurses5-dev"(for which you should have installed the "apt" for 32-bit using "sudo dpkg -i apt_0.8.16~exp12ubuntu10.10_i386.deb" and for 64-bit using sudo dpkg -i apt_0.8.16~exp12ubuntu10.10_amd64.deb")

You need to also install a version of javac compiler using the command "sudo apt-get install openjdk-7-jdk".

Step 4

Once the compilation is over, run the Hello World program.

./hello-world.native

Step 5

This will print the words "Hello, world" on the terminal window. The code will appear to hang, however, it is still running on Contiki, but not producing any output as the Hello World program is finished. Press Ctrl-C to quit.

Hello World on the Tmote Sky!

Step 1

Using the opened terminal window, compile and upload the Hello World program on the Tmote Sky.

make TARGET=sky savetarget (This save the target for any future compilations)

make hello-world.upload (This will upload the code on the Tmote Sky)

make login (This will enable us to view the output. If permission error occurs, use sudo command at the beginning)

Step 2

Press the reset button on the Tmote Sky. The following message will appear on the terminal window

Contiki 2.7 started. Node id is set to 3.

Rime started with address 3.0

MAC 00:12:ff:11:65:23:52:ed

Starting 'Hello world process'

Hello, world

The boot up code of Contiki-OS prints the first four lines whereas the last line is printed by the Hello World program.

Step 3

Press Ctrl-C to quit.

Try This

You can upload and login with one line. You can also point the upload and/or login to a specific device path (use `dmesg` to find the device path of a mote after inserting it to your computer). Try the following command:

make TARGET=sky MOTES=/dev/ttyUSB0 hello-world.upload login

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