1.10 DMAC USART Echo

This example application demonstrates USART transfer with DMA to receive 10 bytes and echo back the received bytes.

Description

This application demonstrates USART transfer with DMA using SERCOM peripheral configured in USART mode. One DMA channel is used to receive 10 bytes of data from the USART and another DMA channel is used to echo back the received bytes.

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/dmac/dmac_usart_echo/firmware.

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

Project NameDescription
pic32mx470_curiosity.XMPLABX project for Curiosity PIC32MX470 Development Board
pic32mx_xlp_sk.XMPLABX project for PIC32MX274 XLP Starter Kit

Setting Up the Hardware

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

Project NameDescription
pic32mx470_curiosity.XCuriosity PIC32MX470 Development Board
pic32mx_xlp_sk.XPIC32MX274 XLP Starter Kit

Setting Up Curiosity PIC32MX470 Development Board

  • To run the demo, the following additional hardware are required:
  • Connect mini USB cable to the ‘Debug USB’ connector(J3) on the board to the computer
  • Install an USB UART click board on to the mikroBUS socket J5
  • Connect mini USB cable between PC and the USB UART click board
    Note: Ensure that the series resistors on the mikroBUS headers are of value 0 Ohms.

Setting Up PIC32MX274 XLP Starter Kit

Running the Application

  1. Open the Terminal application (Ex.: Tera term) on the computer
  2. Connect to the “USB to UART” COM port and configure the serial settings as follows:
    • Baud : 115200
    • Data : 8 Bits
    • Parity : None
    • Stop : 1 Bit
    • Flow Control : None
  3. Build and Program the application project using its IDE
  4. Following message is output on console:
  5. Type 10 characters in the terminal. It will echo back the received bytes and toggles the LED
The following table provides the LED name:
BoardLED Name
Curiosity PIC32MX470 Development BoardLED1
PIC32MX274 XLP Starter KitLED1 (RED)