Feedback

Exercise 1 – Creating an application

Creating an application

In this exercise, we will learn how to create a working “Hello World” application in the nRF Connect SDK from scratch. We are only doing this for educational purposes to expose you to all the elements of an nRF Connect SDK application.

Keep in mind that this is not the recommended way to create an application. As we explained in lesson 1, the recommended way is by using one of the samples that you can find in the SDK as a baseline.

Exercise steps

1. In the exercise folder for this lesson, create a folder and name it l3_e1.

2. Open this folder and create the files needed for a minimum working application.

prj.conf
CMakeLists.txt
src/main.c (this means create a subdirectory called src and then create the empty file main.c)

3. Open CMakeLists.txt and add the minimum functions needed for the application to build (use any editor).

cmake_minimum_required(VERSION 3.20.0)
find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
project(hello_world)
target_sources(app PRIVATE src/main.c)

CMake

cmake_minimum_required ensures the build fails if the CMake version is too old.
find_package pulls in the Zephyr build systems, which creates a CMake target named app.
project sets the name of the project.
target_sources adds the source file to the project.

4. In main.c, include the header file for Zephyr Kernel and the printk module like this:

#include <zephyr/kernel.h>
#include <zephyr/sys/printk.h>

5. In main.c, define the main function to continuously print the statement “Hello World!” and then sleep for a small amount of time (to avoid flooding the console).

int main(void)
{
	while (1) {
		printk("Hello World!\n");
		k_msleep(1000);
	}
}

Note

prj.conf is left empty because the console drivers needed by printk() are enabled by default by the board configuration file. This is covered in-depth in Lesson 4.

6. Let’s add this as an existing application in nRF Connect for VS Code.

Go to nRF Connect for VS Code and under the Welcome View, select Open an existing application and select the directory l3_e1. Observe the project showing up under the Applications View.

7. Just like in Lesson 1, select Add Build Configuration by hovering your mouse over the project name in the Applications View and selecting the icon that appears. Choose the correct board, then select Build Configuration.

8. Flash the application to your board.

9. To view the output of the application, you need to configure a terminal emulator on your machine. You can work in any terminal emulator you want. In this lesson we will show you how to do it using either the built-in terminal emulator in the nRF Connect extension in VS Code (called nRF Terminal), or using the Serial Terminal application nRF Connect for Desktop. You can choose either one using the tabs below.

There are two important parameters when using the UART console:

Speed (baud rate) – the default speed set in the devicetree of Nordic Semiconductor development kits is 115200 bps.
Serial line (COM number) – unlike the speed, this differs from machine to machine. A single board can have multiple serial lines, depending on the board.

Note

Which Virtual COM (VCOM) port to choose?

Nordic development kits come with an interface MCU that serves as a debugger for the development kit. The interface MCU provides additional features such as UART-to-USB conversion and one or more virtual COM ports, depending on your board (VCOM0/COMX, VCOM1/COMX, etc..). These different VCOM ports are intended for specific use cases. For example, one port might be used for TrustedFirmware-M, and another for the application. If you connect to a VCOM port and don’t see the expected output, try selecting the other VCOM port and pressing the reset button on your development kit to get the logs from the beginning.

nRF Terminal
Serial Terminal app

1. To use the terminal emulator in VS code, first go to the Connected Devices tab and open the drop list.

Then open the drop list for that connected device.

Then click the Connect To Serial Port In nRF Terminal icon as shown below.

Then choose the serial terminal which has the following configuration:

Baud rate: 115200 baud/sec
8 bits/character, no parity, 1 stop bit (8n1)
No flow control: rts and cts = off

As shown below:

You should be able to observe the output as shown below

1. Install the Serial Terminal app.

Open nRF Connect for Desktop, navigate to the Serial Terminal app and click Install.

2. Launch the Serial Terminal app.

3. Connect to your board and find the COM ports.

In the upper right hand corner, Select Device.
Select your board, in the example below we are using the nRF7002 DK. This will automatically connect to one of the COM ports on the device.
Select Disconnect from port to configure the settings.
Select the arrow next to the COM port to view all available COM ports for the device

Note the COM numbers assigned to your board. In the screenshot above, it’s COM8 and COM11, but this value is likely to be different on your host machine.

4. Configure the baud rate.

Select Serial Settings to see all available settings for the terminal.
Select the drop down arrow under baud rate to change the baud rate to another value.

We will keep the default value of 115200 for now.

5. Connect to the device.

Once everything is configured, select Connect to port.

Reset your board, and you should be able to observe the output, “Hello World!” printed every second.

*** Booting nRF Connect SDK ***
*** Using Zephyr OS ***
Hello World!
Hello World!
Hello World!

Terminal

The solution for this exercise can be found in the GitHub repository, l3/l3_e1_sol.

Nordic Developer Academy Terms of Service

1. Introduction

‍These terms and conditions (“Terms of Use”) apply to the use of the Nordic Developer Academy, provided by Nordic Semiconductor ASA, org. nr. 966 011 726, a public limited liability company registered in Norway (“Nordic Semiconductor”). ‍

Nordic Developer Academy allows the user to take technical courses related to Nordic Semiconductor products, software and services, and obtain a certificate certifying completion of these courses. By completing the registration process for the Nordic Developer Academy, you are agreeing to be bound by these Terms of Use.

These Terms of Use are applicable as long as you have a user account giving you access to Nordic Developer Academy.‍

‍2. Access to and use of Nordic Developer Academy

‍‍Upon acceptance of these Terms of Use you are granted a non-exclusive right of access to, and use of Nordic Developer Academy, as it is provided to you at any time. Nordic Semiconductor provides Nordic Developer Academy to you free of charge, subject to the provisions of these Terms of Use and the Nordic Developer Academy Privacy Policy.

To access select features of Nordic Developer Academy, you need to create a user account. You are solely responsible for the security associated with your user account, including always keeping your login details safe.

You will able to receive an electronic certificate from Nordic Developer Academy upon completion of courses. By issuing you such a certificate, Nordic Semiconductor certifies that you have completed the applicable course, but does not provide any further warrants or endorsements for any particular skills or professional qualifications.

Nordic Semiconductor will continuously develop Nordic Developer Academy with new features and functionality, but reserves the right to remove or alter any existing functions without notice.

‍3. Acceptable use

You undertake that you will use Nordic Developer Academy in accordance with applicable law and regulations, and in accordance with these Terms of Use.‍ You must not modify, adapt, or hack Nordic Developer Academy or modify another website so as to falsely imply that it is associated with Nordic Developer Academy, Nordic Semiconductor, or any other Nordic Semiconductor product, software or service.

You agree not to reproduce, duplicate, copy, sell, resell or in any other way exploit any portion of Nordic Developer Academy, use of Nordic Developer Academy, or access to Nordic Developer Academy without the express written permission by Nordic Semiconductor. You must not upload, post, host, or transmit unsolicited email, SMS, or \”spam\” messages.

You are responsible for ensuring that the information you post and the content you share does not;

contain false, misleading or otherwise erroneous information
infringe someone else’s copyrights or other intellectual property rights
contain sensitive personal data or
contain information that might be received as offensive or insulting.
Such information may be removed without prior notice.

‍Nordic Semiconductor reserves the right to at any time determine whether a use of Nordic Developer Academy is in violation of its requirements for acceptable use.

Violation of the at any time applicable requirements for acceptable use may result in termination of your account. We will take reasonable steps to notify you and state the reason for termination in such cases.

‍4. Routines for planned maintenance

‍Certain types of maintenance may imply a stop or reduction in availability of Nordic Developer Academy. Nordic Semiconductor does not warrant any level of service availability but will provide its best effort to limit the impact of any planned maintenance on the availability of Nordic Developer Academy.

5. Intellectual property rights

‍Nordic Semiconductor retains all rights to all elements of Nordic Developer Academy. This includes, but is not limited to, the concept, design, trademarks, know-how, trade secrets, copyrights and all other intellectual property rights.

Nordic Semiconductor receives all rights to all content uploaded or created in Nordic Developer Academy. You do not receive any license or usage rights to Nordic Developer Academy beyond what is explicitly stated in this Agreement.

‍6. Liability and damages

‍Nothing within these Terms of Use is intended to limit your statutory data privacy rights as a data subject, as described in the Nordic Developer Academy Privacy Policy. ‍You acknowledge that errors might occur from time to time and waive any right to claim for compensation as a result of errors in Nordic Developer Academy. When an error occurs, you shall notify Nordic Semiconductor of the error and provide a description of the error situation.

You agree to indemnify Nordic Semiconductor for any loss, including indirect loss, arising out of or in connection with your use of Nordic Developer Academy or violations of these Terms of Use. ‍Nordic Semiconductor shall not be held liable for, and does not warrant that (i) Nordic Developer Academy will meet your specific requirements, (ii) Nordic Developer Academy will be uninterrupted, timely, secure, or error-free, (iii) the results that may be obtained from the use of Nordic Developer Academy will be accurate or reliable, (iv) the quality of any products, services, information, or other material purchased or obtained by you through Nordic Developer Academy will meet your expectations, or that (v) any errors in Nordic Developer Academy will be corrected.

You accept that this is a service provided to you without any payment and hence you accept that Nordic Semiconductor will not be held responsible, or liable, for any breaches of these Terms of Use or any loss connected to your use of Nordic Developer Academy. Unless otherwise follows from mandatory law, Nordic Semiconductor will not accept any such responsibility or liability.

‍7. Change of terms

‍Nordic Semiconductor may update and change the Terms of Use from time to time. Nordic Semiconductor will seek to notify you about significant changes before such changes come into force and give you a possibility to evaluate the effects of proposed changes. Continued use of Nordic Developer Academy after any such changes shall constitute your acceptance of such changes. You can review the current version of the Terms of Use at any time at https://academy.nordicsemi.com/terms-of-service/

‍8. Transfer of rights

‍Nordic Semiconductor is entitled to transfer its rights and obligation pursuant to these Terms of Use to a third party as part of a merger or acquisition process, or as a result of other organizational changes.

‍9. Third Party Services

‍‍To the extent Nordic Developer Academy facilitates access to services provided by a third party, you agree to comply with the terms governing such third party services. Nordic Semiconductor shall not be held liable for any errors, omissions, inaccuracies, etc. related to such third party services.

‍10. Dispute resolution

‍‍The Terms of Use and any other legally binding agreement between yourself and Nordic Semiconductor shall be subject to Norwegian law and Norwegian courts’ exclusive jurisdiction.

nRF Connect SDK Fundamentals

Exercise 1 – Creating an application

Creating an application

Exercise steps

Note

Note

Switch language?

Change summary

What's new in the latest version

General updates

Bluetooth LE updates

MCUboot & Partition Manager

General updates

Bluetooth LE updates

Bootloader updates