3.3.10 USART Hardware Handshaking Configuration in SAM D21 Curiosity Nano Evaluation Kit

Description

This application demonstrates the hardware handshaking functionality of USART communication between two SAM D21 Curiosity Nano Evaluation Kits. The host and client can send/receive data with the help of serial consoles.

Modules/Technology Used

Peripheral Modules
- NVMCTRL
- EVSYS
- SERCOM

Hardware Used

Software/Tools Used

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

Refer Project Manifest present in harmony-manifest-success.yml under the project folder firmware/src/config/sam_d21_cnano.

Refer the Release Notes to know the MPLAB X IDE and MCC Plugin version.
Any Serial Terminal application, such as Tera Term terminal application.

Because Microchip regularly updates tools, occasionally issue(s) could be discovered while using the newer versions of the tools. If the project does not 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. To download original version of MPLAB Harmony v3 packages, refer to document How to Use the MPLAB Harmony v3 Project Manifest Feature (DS90003305).

Setup

Connect the Type-A male to Micro-B USB cable to Micro-B DEBUG USB port (J900) to program and debug the SAM D21 Curiosity Nano Evaluation Kit.
Connect the pins according to the table given below.
Host side Client side Logic Analyzer
TX - PA16 RX - PA17 Channel 0
RX - PA17 TX - PA16 Channel 1
RTS - PA18 CTS - PA19 Channel 2
CTS - PA19 RTS - PA18 Channel 3
GND GND GND
Note: A custom protoboard or breadboard is required, to connect the channels of the logic analyzer with the boards to probe the signals.

Host side	Client side	Logic Analyzer
TX - PA16	RX - PA17	Channel 0
RX - PA17	TX - PA16	Channel 1
RTS - PA18	CTS - PA19	Channel 2
CTS - PA19	RTS - PA18	Channel 3
GND	GND	GND

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,
1. Create Prebuilt Project,
  - Click the Browse button to select the prebuilt hex file.
  - Select Device as ATSAMD21G17D.
  - Ensure the proper tool is selected under Hardware Tool and click on Next button.
2. Select Project Name and Folder,
  - Select appropriate project name and folder and click on Finish button
In MPLAB X IDE, click on Make and Program Device button to program the device.
Follow the steps in Running the Demo section below.

Programming/Debugging Application Project

Open the project (sam_d21_cnano_usart_hardware_handshaking\firmware\sam_d21_cnano.X) in MPLAB X IDE
Ensure SAM D21 Curiosity Nano is selected as hardware tool to program/debug the application
Build the code and program both the devices 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

Open Logic 2 software (from the Windows Start menu by pressing the Start button).
Reset or power cycle both the devices.
After programming both the devices with the provided code, click the Run button to view the USART communication in the Logic 2 software.
Below diagram shows the output displayed on salae Logic 2 software.

Comments

Reference Training Module: Getting Started with Harmony v3 Peripheral Libraries on SAM D21 MCUs
This application demo builds and works out of box by following the instructions above in Running the Demo section. If the user needs to enhance/customize this application demo, should use the MPLAB Harmony v3 Software framework. Refer links below to setup and build the applications using MPLAB Harmony.