Link Search Menu Expand Document

SD Card Reader and Audio-Tone Application by reading the tone from a text file stored in an SD card on PIC32MZ Embedded Connectivity with FPU Starter Kit + Multimedia Expansion Board II

Download

Description

The application shows how to edit the contents of an SD card. The PIC32 Multimedia Expansion Board II (MEB II) is connected to a USB host, (typically a PC) and after a successful enumeration, the SD card is presented as a mass storage drive on the PC allowing you to add or delete contents.

The application reads an audio text file from the PIC32 Multimedia Expansion Board II (MEB II) SD card and streams it over the PIC32 I²S interface to the audio CODEC. The audio file is saved as a .txt file with comma-separated left and right channel audio data.

Modules/Technology Used:

  • Peripheral Modules
    • I2C
    • I2S
    • Timer
    • Core Timer
  • Drivers
    • I2S Driver
    • I2C Driver
    • AK4953 Driver
    • SDCARD (SPI) Driver
    • USB High Speed Driver
    • MSD Function Driver
  • BSP Library
    • PIC32MZ EF Starter Kit BSP
  • System Services
    • File System
  • Middleware
    • USB device layer

Hardware Used:

Note: This application is a reference only to the existing users of Multimedia Expansion Board II (MEB II) to port/develop their application(s) using MPLAB Harmony v3 as the Multimedia Expansion Board II (MEB II) is now a matured product and the same is not available for purchase from Microchip Direct.

Software/Tools Used:

This project has been verified to work with the following versions of software tools:

Because Microchip regularly update tools, occasionally issue(s) could be discovered while using the newer versions of the tools. If the project doesn’t seem to work and version incompatibility is suspected, It is recommended to double-check and use the same versions that the project was tested with.

Setup:

  • Connect the PIC32MZ Embedded Connectivity with FPU (EF) Starter Kit to the Host PC as a USB Device through a Type-A male to micro-B USB cable connected to Micro-B USB (Debug USB) port.
  • Connect the wired stereo headphone to the audio jack

Note: It is not necessary to have an MPLAB Real ICE™ to program/debug the code. The PIC32MZ EF Starter Kit includes a PICkit™ on-board (PKOB) debugger. The PKOB debugger can be connected to a host PC through the USB Mini-B connector on the PIC32MZ EF Starter Kit for programming/debugging (see the red cable in the hardware setup).

Programming hex file:

The pre-built hex file can be programmed by following the below steps.

Steps to program the hex file

  • Open MPLAB X IDE
  • Close all existing projects in IDE, if any project is opened.
  • Go to File -> Import -> Hex/ELF File
  • In the “Import Image File” window, Step 1 - Create Prebuilt Project, Click the “Browse” button to select the prebuilt hex file.
  • Select Device has “PIC32MZ2048EFH144”
  • Ensure the proper tool is selected under “Hardware Tool”
  • Click on Next button
  • In the “Import Image File” window, Step 2 - Select Project Name and Folder, select appropriate project name and folder
  • Click on Finish button
  • In MPLAB X IDE, click on “Make and Program Device” Button. The device gets programmed in sometime
  • Follow the steps in “Running the Demo” section below

Programming/Debugging Application Project:

  • Open the project (audio_player_lab3/firmware/audio_player_lab3.X) in MPLAB X IDE
  • Ensure “PKOB” is selected as hardware tool to program/debug the application
  • Build the code and program the device by clicking on the “make and program” button in MPLAB X IDE tool bar
  • Follow the steps in “Running the Demo” section below

Running the Demo:

  • Delete any tone.txt file on the micro SD card. You will load the tone.txt file using the newly added SD card reader functionality
  • Ensure micro SD card is inserted into the micro SD card slot (J8) on the MEB II
  • Connect a USB cable from the micro USB connector (J4) on the PIC32MZEF Starter Kit board to the PC
  • Connect a headphone to the HP Out connector on the Multimedia Expansion Board II
  • The application boots in the SD Card Player mode. You will not be able to hear the tone as the tone.txt file was already deleted from the micro SD card
  • To Load the tone.txt file to the SD card from the PC, Press the switch S1 on the MEB II
  • Wait for the PC to enumerate the USB MSD. Verify that the device appears as a Removable Storage Device. On a Windows machine, do this by clicking on the My Computer (or Computer) icon. Click on the drive and copy the tone.txt file
  • Once the tone.txt file is copied in SD card, press the S1 button to go back to the Player mode
  • Plug your earphones in and you should be able to listen to the tone!

Comments:

Revision:

  • v1.2.0 regenerated and tested the application
  • v1.1.0 regenerated and tested the application
  • v1.0.0 released demo application


Copyright © 2020 Microchip Technology.