1.4 SPI Driver Asynchronous - Self Loopback Multi Client

This example demonstrates the multi client feature of the SPI driver by performing self-loop back with two clients connected on the same SPI bus.

Description

  • This example demonstrates the multi client feature of the SPI driver by reading and writing data with two clients that are connected on the same SPI bus.
  • 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. This content can also be downloaded using content manager by following these instructions.

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

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

Project NameDescription
sam_ha1_xpro.XMPLABX project for SAM HA1G16A Xplained Pro Evaluation Kit

Setting Up the Hardware

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

Project NameDescription
sam_ha1_xpro.X SAM HA1G16A Xplained Pro Evaluation Kit

Setting Up SAM HA1G16A Xplained Pro Evaluation Kit

  • Use jumper wire to Connect “Pin 16 of EXT1 header” to “Pin 17 of EXT1 header”
    • SPI0 MOSI signal is mapped to PA04 that is routed to “Pin 16 of EXT1 header”
    • SPI0 MISO signal is mapped to PA11 that is routed to “Pin 17 of EXT1 header”
  • Connect the Debug USB port on the board to the computer using a micro USB cable
    Note: ATSAMHA1G16A device in SAM HA1G16A Xplained Pro board is not recommended for new design, hence replace the device with ATSAMHA1G16AB device. Connect the supported external.

Running the Application

  1. Build and program the application using its IDE
  2. The LED is turned ON on Success
Refer to the following table for LED name: