1. Introduction

1.1. Before You Start

Before you start you need to:

• Install the latest SmartSnippets Studio
• Download the latest SDK for the DA1468x platforms

These can be downloaded from the Dialog Semiconductor support portal.

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

The key goals of this tutorial are to:

• Provide a basic understanding of adapters concept
• Explain the different APIs and configurations of I²C peripheral adapters
• Give a complete sample project demonstrating the usage of I²C peripheral adapters

1.2. I²C Adapters Introduction

This tutorial explains I²C adapters and how to configure the DA1468x family of devices as an I²C Master device. Adopting an I²C Slave role is not used for the majority of situations and so is not covered in this tutorial. The I²C adapter is an intermediate layer between the I²C Low Level Drivers (LLDs) and a user application. It allows the user to utilize the I²C interface in a simpler way than when using APIs from LLDs. The key features of I²C adapters are:

• Synchronous writing/reading operations block the calling freeRTOS task while the operation is performed using semaphores rather than relying on a polling loop approach. This means that while the hardware is busy transferring data, the operating system (OS) scheduler may select another task for execution, utilizing processor time more efficiently. When the transfer has finished, the calling task is released and resumes its execution.
• A DMA channel can be used among various peripherals (for example, I²C, UART). Interconnected peripherals may use the same DMA channel if necessary. The adapter takes care of DMA channel resource management.
• It ensures that only one device can use the I²C bus after acquiring it.
• Placing code between ad_i2c_bus_acquire() and ad_i2c_bus_release() ensures that only one task can use the I²C bus to communicate with an external connected device. During this period no other device or task can use the I²C interface until the ad_i2c_bus_release() function is called by the owning task.
• Power Manager (PM) of the chip is aware of the I²C peripheral usage and before the system enters sleep, it checks whether or not there is activity on the I²C bus.

Note

Adapters are not implemented as separate tasks and should be considered as an additional layer between the application and the LLDs. It is recommended to use adapters for accessing a hardware block.

Fig. 1 Adapters Communication