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# 1.6 SPI Driver Asynchronous - Self Loopback Multi-client

This example demonstrates how to use the SPI driver in asynchronous mode to achieve self loopback between multiple clients.

## Description

- This example writes and reads back the same data (self loopback) for two different clients connected over the same SPI bus by using the multi-client feature of the driver
- It uses the request (write and read request) queuing feature of the asynchronous driver and does not waste Central Processing Unit (CPU) bandwidth in waiting for previous request completion
- The example demonstrates how to set up two different client transfers at different baud rates
- This example performs self loopback only once after a power on reset
- Success is indicated when a successful self loopback is reported by both the clients
- After the loopback test is complete, the application remains in the idle state

## Downloading and Building the Application

To clone or download this application from Github, go to the main page of this repository and then click Clone button to clone this repository or download as zip file.

Path of the application within the repository is apps/driver/spi/async/spi_self_loopback_multi_client.

To build the application, refer to the following table and open the project using its IDE.

Project Name | Description
--- | ---
pic32wm_bw1_curiosity.X | MPLAB X project for PIC32WM-BW1 Curiosity board

## Setting Up the Hardware

The following table shows the target hardware for the application projects.

Project Name | Description
--- | ---
pic32wm_bw1_curiosity.X | PIC32WM-BW1 Curiosity board

### Setting Up PIC32WM-BW1 Curiosity Board

- Use jumper wire to connect MOSI to MISO pins on the mikroBUS socket of the curiosity board
- Connect the USB port on the board to the computer using a USB Type-C cable

## Running the Application

1. Build and program the application using its IDE.
2. LED is turned ON on success.

Refer to the following table for LED name:

Board | LED Name
--- | ---
PIC32WM-BW1 Curiosity board | Green LED