4. Analyzing The Application Example

This section analyzes an example application demonstrating the use of the I²C adapter, based on the freertos_retarget sample code found in the SDK. It implements a simple request/response communication scenario over the I2C interface using the I2C adapter layer.

In this application DA1459x is configured as I²C master while HS3001 sensor is used as an I²C slave device. Link to the example. Follow the README mentioned on the Github to run the example code.

4.1. Application Structure

The I2C master initiates a write-then-read transaction sending a request string to the slave.

Depending on the value of the I2C_ASYNC_EN macro, a synchronous or asynchronous I²C read operation is attempted.

Figure 2 I2C Write & Read - Main Execution Path

It is essential that developers must not call asynchronous related APIs without guaranteeing that the previous asynchronous transaction is finished. To ensure this, after triggering an asynchronous I²C read transaction, the calling task blocks its execution until the arrival of a freeRTOS signal, indicating the end of the current I²C operation.

Figure 3 Async I2C write & read - Callback function Execution Path