SAM7L-EK Demo Project 1.4

Purpose

This application demonstrates several features of the newly-introduced AT91SAM7L device family. This includes their low-power modes, the segment LCD controller, and the external keyboard matrix available on the Evaluation Kit.

Description

Upon startup the SLCD show display the following screen:

This first screen shows the board name, the Atmel logo, a battery level indicator and a clock. Note that the battery and clock are actually displayed in all modes of operations.

Pressing the 'Mode' key while on the startup screen brings up a menu with the following choice:

• Revision: displays the demo version number.
• Calculator: enters calculator mode.
• Setup: displays a sub-menu with configuration options.
• Board Name: edits the startup screen board name.
• LCD Contrast: changes the segment LCD contrast.
• Power Save: changes the idle time before power save mode is entered.
• Date: edits the current date.
• Time: edits the current time.

In calculator mode, the device behave as a simple calculator. It only performs integer operations. To clear the current result, use the 'Del' key; to return to the main menu use 'Mode', and to the startup screen 'Esc'.

Technical Details

This section briefly explains which features of the AT91SAM7L-EK are demonstrated and how.

Segment SLCD

The segment LCD is used to display the user interface. The blink mode provided by the SLCD controller is demonstrated in the various edit modes (available from the Setup sub-menu).

Low-power Modes

The device uses two low-power modes. The first one is used continuously whenever the user is not pressing any key; the SLCD is still enabled, and wake-up is programmed on the wake-up inputs connected to the keyboard. As soon as the clock needs to be refresh or if the user presses a key, the device enters normal mode, performs the necessary actions, and returns to backup mode.

The second form of low-power mode, called deep backup, is entered after a sustained period of inactivity. In this case, the SLCD screen is shut down, and the device can only be turned back on by pressing the force wake-up button. It stills retain all the information that had been entered and will restart in the previously used mode.

Brown-out Detector

The brown-out detector is used to monitor the battery life. It is configured to continuously monitor the battery, the threshold being adjusted between several pre-defined ranges.

Real-time Clock

The RTC is used to display the clock on the screen, as well as indicating whenever the device shall enter deep backup mode.

Keyboard

The keyboard is used to interact with the demo program. It supports multiple simultaneous key presses, and handles the 2ndF and 2ndF lock keys to toggle between the main and alternate keyboards.

Usage

1. Erase the current contents of the internal flash by closing the Erase jumper on the board and pressing the 'Reset' button, then the 'Wake-up' button.
2. Remove the Erase jumper and restart the ROM code by pressing 'Reset' then 'Wake-up'.
3. Build the program and download it inside the internal flash of the chip. Please refer to the SAM-BA User Guide for more information on that step.
4. Optionally, on the computer, open the DBGU port with a terminal application (e.g. HyperTerminal on Microsoft Windows), to see debug traces output by the example.
• Settings: 115200 bauds, 8 bits, 1 stop bit, no parity, no flow control.
5. On the evaluation kit, set the following jumpers as described:
   • J1.4: closed
   • J106: closed
   • J107: between pins 1 & 2
   • J108: between pins 1 & 2
   • J109: open
6. Start the application by pressing the 'Reset' then 'Wake-up' buttons.
7. The startup menu should appear after a few seconds. Please see the description section for more information about the contents of the demo.

Atmel Corporation ©2008