Example Summary

This application moves into and out of shutdown. The state is controlled by buttons. CONFIG_BUTTON_SHUTDOWN will send the device into shutdown, while CONFIG_GPIO_WAKEUP will wake-up the device. A special LED toggling sequence is used when waking from shutdown to demonstrate the get-reset-source functionality.

Peripherals Exercised

• CONFIG_BUTTON_SHUTDOWN - Used to tell the device to enter shutdown.
• CONFIG_GPIO_WAKEUP - Used as a wake-up source.
• CONFIG_LED_0 - Lit when the device is active, not lit when in shutdown.
• CONFIG_LED_1 - Will blink when coming out of shutdown.

BoosterPacks, Board Resources & Jumper Settings

For board specific jumper settings, resources and BoosterPack modifications, refer to the Board.html file.

If you’re using an IDE such as Code Composer Studio (CCS) or IAR, please refer to Board.html in your project directory for resources used and board-specific jumper settings.

The Board.html can also be found in your SDK installation:

<SDK_INSTALL_DIR>/source/ti/boards/<BOARD>

In order to get lowest shutdown current, it may be relevant to disconnect debug interface pins by removing relevant jumpers to avoid extra leakage current. Please see the Board.html file.

Example Usage

• Run the example. Use CONFIG_BUTTON_SHUTDOWN and CONFIG_GPIO_WAKEUP to shutdown and wake-up the device. Try the RESET button to compare the different start-up sequences used.

It is not possible to do a proper shutdown sequence with the debugger connected. For correct behavior, this example must be run with the debugger disconnected by resetting or performing a power-cycle of the device.

Application Design Details

• The example consists of one task which waits for a button press and then calls Power_shutdown(). Since no other power resources are active, the device will shutdown immediately and then reset on the opposite button press.
• Demonstrates the use of Power_getResetSource() to determine the previous reset source, and blinks an LED if we reset due to shutdown.

FreeRTOS:

• Please view the FreeRTOSConfig.h header file for example configuration information.