1.11 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
pic32mm_usb_curiosity.XMPLABX project for PIC32MM USB Curiosity board

Setting up the hardware

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

Project NameDescription
pic32mm_usb_curiosity.XPIC32MM USB Curiosity board

Setting up PIC32MM USB Curiosity Board

  • To run the demo, the following additional hardware are required:
  • Connect micro USB cable to the 'USB1' on the board to the computer
  • Install an USB UART click board on to the mikroBUS socket J4
  • 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

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

Following table provides LED name:

BoardLED Name
PIC32MM USB Curiosity boardLED1