1.5 SPI Driver Asynchronous - Self Loopback Multi Client

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

Description

  • This example writes and reads back the same data (self loop back) 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 CPU bandwidth in waiting for previous request completion.
  • The example also demonstrates how to setup two different client transfers at different baud rates.
  • This example performs self loop back only once after a power on reset.
  • Success is indicated when a successful self loop back is reported by both the clients.
  • After the loop back 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 NameDescription
pic32ak_gc_curiosity.XMPLABX project for Curiosity Platform Development Board and PIC32AK1216GC41064 General Purpose Dual In-Line Module (DIM)

Setting Up the Hardware

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

Setting Up Curiosity Development Board

  • Use jumper wire to connect “Pin 5 (MISO) of mikroBUS A header” to “Pin 6 (MOSI) of mikroBUS A header”
    • SPI1 SDO1 signal as MOSI signal and it is mapped to RC11 that is routed to “Pin 5 of mikroBUS A header”
    • SPI1 SDI1 signal as MISO signal and it is mapped to RD11 that is routed to “Pin 6 of mikroBUS A header”
  • Insert the GP DIM on to DIM slot of Curiosity Board
  • Connect the PKoB (J24) on the board to the computer using a USB type-C cable