Basic RTT Project 1.4

Purpose

This example demonstrates the Real-Time Timer (RTT) provided on AT91 microcontrollers. It enables the user to set an alarm and watch it being triggered when the timer reaches the corresponding value.

Description

When launched, this program displays a timer count and a menu on the DBGU, enabling the user to choose between several options:

• Reset the timer
• Set an alarm time
• Clear an alarm notification if one is being displayed

The user can set an alarm time by selecting option 2 ('s'), entering the alarm time and pressing the enter key. Once the alarm is set, a message will be displayed when the corresponding time is reached.

Usage

1. Build and download the program inside the evaluation board. Please refer to the SAM-BA User Guide, the GNU-Based Software Development application note or to the IAR EWARM User Guide, depending on your chosen solution.
2. On the computer, open the DBGU port with a terminal application (e.g. HyperTerminal on Microsoft Windows).
• Settings: 115200 bauds, 8 bits, 1 stop bit, no parity, no flow control.
3. Start the application.
4. The application menu should appear as shown below:

   -- Basic RTT Project 1.4 --
Time: 0
Menu:
r - Reset timer
s - Set alarm

Choice?


   The user can then choose any of the available options to perform the described action.

Atmel Corporation ©2008