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# 1.29 SERCOM USART Blocking

This example application demonstrates how to use the SERCOM peripheral in USART mode to transfer block of data in a blocking manner.

## Description

This example shows the read and write operation over a USART in a blocking manner. The CPU polls the peripheral register continuously to manage the transfer. It receives a line of characters from the terminal window and echoes them back.

## Downloading and Building the Application

To clone or download this application from Github, go to the main page of this repository and then click Clone button to clone this repository or download as zip file. This content can also be downloaded using content manager by following these instructions.

Path of the application within the repository is apps/sercom/usart/usart_echo_blocking/firmware.

To build the application, refer to the following table and open the project using its IDE.

Project Name | Description
--- | ---
sam_d21_xpro.X | MPLABX project for SAM D21 Xplained Pro Evaluation Kit
sam_da1_xpro.X | MPLABX project for SAM DA1 Xplained Pro Evaluation Kit

## Setting Up the Hardware

The following table shows the target hardware for the application projects.

Project Name | Description
--- | ---
sam_d21_xpro.X | SAM D21 Xplained Pro Evaluation Kit
sam_da1_xpro.X | SAM DA1 Xplained Pro Evaluation Kit

### Setting Up SAM D21 Xplained Pro Evaluation Kit

- Connect the Debug USB port on the board to the computer using a micro USB cable

### Setting Up SAM DA1 Xplained Pro Evaluation Kit

- Connect the Debug USB port on the board to the computer using a micro USB cable

## Running the Application

1. Open the Terminal application (Ex.:Tera term) on the computer
2. Connect to the EDBG Virtual COM port and configure the serial settings as follows:
   - Baud : 115200
   - Data : 8 Bits
   - Parity : None
   - Stop : 1 Bit
   - Flow Control : None
3. Build and Program the application using its IDE
4. The console displays the following message
5. Type a line of characters and press the Enter key
   Note: Number of characters entered before pressing enter key must be less than 256.
6. Entered line will be echoed back and the LED is toggled
7. The following table provides the LED name:

   Board | LED Name
   --- | ---
   SAM D21 Xplained Pro Evaluation Kit | LED0
   SAM DA1 Xplained Pro Evaluation Kit | LED0