Low Power Application on SAM L21 Using MPLAB® Harmony v3 Peripheral Libraries: Step 1

Last modified by Microchip on 2023/11/10 11:00

Create Project and Configure the SAM L21

Verify MPLAB® Harmony Configurator (MHC) Plugin is Installed in MPLAB X IDE

Verify that MHC is installed.

• Launch MPLAB X IDE from the Microsoft Windows® Start menu. Close any projects and files that are currently open.
• Go to Tools > Embedded.
• You will see MPLAB Harmony 3 Configurator in the menu.

Tools > MPLAB Harmony 3 Configurator menu

If you don't see it in the menu, install MHC.

Setup MHC Plugin Window to Open in Standalone Mode

Go to Tools > Options in the MPLAB X IDE toolbar:

Tools > Options menu​​​​​​
Options window​​​​

Go to Plugins > Window Manager and select Standalone mode. Click Apply and then click OK:

Options window​​​​

  • When you launch MHC for the first time, it displays a prompt asking for the mode in which you would like to use MHC.
    • Standalone mode (as a separate window)
    • Native mode (as an embedded window in MPLAB X IDE)
  • Standalone mode is the default mode.
  • MHC will launch in the operating mode selected the first time, every time you launch MHC.

Step 1.2 above shows a way to change the MHC operating mode.

For this lab, MHC is configured to operate in Standalone mode.

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Create MPLAB Harmony v3 Project Using MPLAB X IDE

Select File > New Project from the main IDE menu.

In the Categories pane of the New Project dialog box, select Microchip Embedded. In the Projects pane, select 32-bit MPLAB Harmony 3 Project, then click Next.

Choose Project pane​​​

In the Framework Path edit box, browse to the folder you downloaded the framework to. If you haven't done this, or want to download it to a different folder, click the Launch Content Manager button, then click Next.

For more information on the framework downloader, see the "Download MPLAB Harmony Framework" section of the "MPLAB Harmony Configurator Overview" page.

Manage Framework pane​​

In the Project Settings window, apply the following settings:

  • Location: Indicates the path to the root folder of the new project. All project files will be placed inside this folder. The project location can be any valid path, for example, <Your_folder>\dev\saml21_low_power.

  • Folder: Indicates the name of the MPLABX .X folder. Enter "sam_l21_xpro" to create a sam_l21_xpro.X folder.
  • Name: Indicates the name of the project that will be shown in the MPLAB X IDE. Enter "low_power_sam_l21_xpro" to set the project's name.

Note: The Path box is read-only. It will update as you make changes to the entries.

  • Click Next to proceed to Configuration Settings.
    Name and Location pane​​

Note: Clicking on the Show Visual Help button will open a Help window providing a detailed description of the various fields in the Project Settings window.

New Project wizard​​

Follow the steps below to set the project’s Configuration Settings.

  • Name: Enter the configuration name as "sam_l21_xpro".

  • Target Device: Select ATSAML21J18B as the target device.

Note: You can select the Device Family or enter a partial device name to filter the list in Target Device to make it easier to locate the desired device.

  • After selecting the target device, click Finish to launch MHC.

Configuration Settings pane​​

Note: The New Project Wizard opens a Configuration Settings window to allow you to review the packages that will be used by the current project.

Before proceeding, set up the compiler toolchain. Click on the Projects tab on the top left pane in the MPLAB X IDE. Right click on the project name "low_power_sam_l21_xpro" and go to Properties.

Projects tab menu​​

Make sure that XC32 (v2.30) is selected as the Compiler Toolchain for XC32. Click on Apply and then click on OK.

Configuration pane​​

Launch MHC from MPLAB X IDE by clicking on Tools > Embedded > MPLAB Harmony 3 Configurator.

Tools > Embedded > MPLAB Harmony 3 Configurator menu​​

Select the Harmony framework's path to be loaded.

Harmony Launcher window​​

Click Launch to launch the MHC Configuration tool.

Configure Device Family and CMSIS Pack Paths window​​

The MHC plugin’s main window for the project will be displayed.

Project Graph pane

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Configure Clock Settings

Launch Clock Easy View by going to the MHC tab in MPLABX IDE and then select Tools > Clock Configuration.

Tools > Clock Configuration window

The Clock Easy View window will then appear on your screen.

Clock Easy View window

Tool Tip: Double-click on Clock Easy View tab to maximize the window.

Enable the 16 MHz Internal Oscillator (OSC16M) and select the 12 MHz ouput in the Oscillator Controller box.

Oscillator Controller box diagram

Disable the Digitial Frequecy Locked Loop (DFLL).

Digitial Frequecy Locked Loop (DFLL) diagram

Set the OSC16M as the Generic Clock Generator 0 (GCLK0) source clock.

Generic Clock Generator 0 diagram

Enable the GCLK1 and set the OSC16M as the GCLK1's clock source.

GCLK1 diagram

Enable the GCLK2 and set the OSCULP32K as the GCLK2's clock source. Then, click on the Settings (wheel) button in the top right.

GCLK2 diagram

The Advanced Settings window will appear after clicking on the Settings (wheel) button. Check the box for GCLK should keep running in Standby mode.

Advanced Settings window

Select the OSCULP1K as the RTC's source clock.

OSCULP1K diagram

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