1. Introduction

1.1. Before You Start

Before you start you need to:

  • Install the latest Smartsnippets Studio

  • Download the latest SDK for the DA1469x platforms

These can be downloaded from the DA1469x product page.

Additionally, for this tutorial a Pro Development kit is required.

The key goals of this tutorial are to:

  • Provide a basic understanding of the external interrupt mechanism

  • Set up a working demonstration handling an external interrupt and taking action

  • Trigger an OS task execution based on the collected external interrupt

1.2. External Interrupt

An external interrupt is where the processor activity is interrupted and the ARM Cortex M33 handler mode is entered based on the rising and/or falling edge of a GPIO pin. Any GPIO pin on the DA1469x chip can be used to generate an interrupt which will trigger the ARM Cortex M33. The process is handled by the block called Wake-Up Timer. This peripheral consists of two sub blocks:

  • The KEY sub block which involves a debounce circuitry with maximum debouncing time at 63ms. The signals generated from this block are directly connected to the ARM Cortex M33 interrupt controller to indicate that a button has been pressed.

  • The GPIO sub block which does not involve a debounce circuitry. This block generates signals to the Power Domain Controller (PDC) when one or more GPIOs are toggling. The edge of the generated signals is captured and latched into a status register.

1.3. Working Demonstration

As the Bluetooth low energy framework runs under the supervision of a Real Time Operating System (RTOS), the example in this tutorial demonstrates how to trigger a task execution based on the collected event.