#ASF library required to follow the Acme Systems Yarm tutorials

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This article illustrates how to add the minimal set of ASFlibraries requested to follow the Acme Systems Yarm tutorials
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## Add the ASF libraries required by your project

The [Atmel Software Framework (ASF)](http://www.atmel.com/tools/avrsoftwareframework.aspx) is a large collection of libraries 
included by Atmel inside Atmel Studio to simplify our job with an abstraction of the internal MPU peripherals. 

To use the ASF modules in your project select <i>Project -> ASF Wizard</i> and then 
your project name from the <i>Project</i> drop down list.

<img class="img-responsive center-block" width="40%" src="./asf_wizard_project_selection.jpg">

Drag and drop the modules to include in your project from the left side to the right side. 

<img class="img-responsive center-block" width="80%"   src="./available_modules.jpg">

Add these ASF modules to do a simple blinking led code example:

* Generic board support (driver)
* Delay routines (service) [cycle]
* EXTINT - External Interrupt (driver) [callback]
* PORT - GPIO Pin Control (driver)
* RTC - Real Time Counter Driver (driver) [count_callback]
* SERCOM I2C - Master Mode I2C (driver) [polled]
* SERCOM SPI - Serial Peripheral Interface (driver) [callback]
* SERCOM USART - Serial Communication (driver) [polled]
* SYSTEMS - Core Systems Driver (driver)
* Standard serial I/O (stdio) (driver)
* IOPORT – General Purpose I/O (service)
* TC – Timer Counter (driver) [callback]

Press the <kbd>Apply</kbd> button to confirm the operation.

##Links 

* [ASF modules for SAML21](http://asf.atmel.com/docs/latest/search.html?device=saml21)

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