Getting Started with MPLAB® Harmony v3 Drivers and System Services on SAM E70/S70/V70/V71 MCUs
Objective
MPLAB® Harmony v3 is a flexible, fully integrated embedded software development framework for 32-bit microcontrollers (MCUs) and microprocessors (MPUs).
MPLAB Harmony v3 includes the MPLAB Code Configurator (MCC) tool, a set of modular devices and middleware libraries. Additionally, there are numerous example applications, all of which are designed to help you quickly and easily develop powerful and efficient embedded software for Microchip’s 32-bit PIC® and SAM devices.
This tutorial shows you how to use MCC to create an application that gets you started in developing applications on SAM E70/S70/V70/V71 MCUs using the MPLAB Harmony v3 software framework.
The application makes use of the SAM E70 Xplained Ultra Evaluation Kit and I/O1 Xplained Pro Extension Kit (sold separately).
The application reads the current room temperature from the temperature sensor on the I/O1 Xplained Pro Extension Kit. The temperature reading is displayed on a serial console periodically every second. Further, the application writes the temperature readings to EEPROM. When a character is entered on the console, the last five written temperature values are read from the EEPROM and displayed on the console. Also, an LED (LED3) is toggled every time the temperature is displayed on the serial console.
The application you create will utilize:
- Two-Wire Interfaces (TWIHS) (I²C) Driver to read the temperature from a temperature sensor and store/retrieve to/from EEPROM.
- Timer System Service to periodically sample temperature sensor data.
- Universal Synchronous Asynchronous Receiver Transmitter (USART) Driver (in Direct Memory Access (DMA) mode) to print the temperature values on a COM (serial) port terminal application running on a PC.
- PORTS Peripheral Library to toggle an LED.
In the process, the lab will also demonstrate the use of callback functions.
Two Ways to Use This Tutorial
- Create the project from scratch:
- Use the provided source files and step-by-step instructions below.
- Use the solution project as an example:
- Build the solution project and download it to the SAM E70 Xplained Ultra Evaluation Kit Board to observe the expected behavior.
Lab Objectives
- Create an MPLAB X IDE Harmony v3 project for a SAM E70 microcontroller from scratch.
- Use MCC to configure and generate Harmony Driver code for I²C and USART peripherals.
- Along with the configuration of drivers for I²C and USART peripherals, use MCC to configure and generate Harmony v3 peripheral libraries for the I²C, USART, DMA, and PORTS peripherals.
- Use MCC to configure and generate the Harmony System Service code for the Timer peripheral.
- Along with the configuration of the Timer System Service, use MCC to configure and generate Harmony v3 peripheral libraries for the TC peripheral.
- Use the Harmony v3 Driver, System Service, and Peripheral Library Application Programming Interfaces (APIs) to implement the application.
Hardware Resources
Hardware Connection Setup
Figure 1
Apart from the hardware tools listed above, the following items are required:
- USB Type-A male to Micro-B male cable for programming/debugging.
Connection Diagram
The application has the temperature sensor and EEPROM connected to the SAM E70 over the I²C interface and the console (serial terminal) on a PC connected over the USART interface (through USB to USART converter).
Figure 2
Hardware Modification
IO1 Xplained Pro features Microchip’s AT30TSE758 temperature sensor chip with an 8 kbit serial EEPROM. The temperature sensor has two TWI addresses—one for the temperature sensor and one for the EEPROM. The A2 address line of TWI must be soldered to 0. This is done to modify the address of the EEPROM on the I/O1 Xplained Pro Extension Kit so that it does not conflict with the address of EEPROM on the SAM E70 Xplained Evaluation Kit. The modification changes the address of the temperature sensor to 0x4B and EEPROM to 0x50. These modified addresses are used in this tutorial.
The hardware modification on the IO1 Xplained Pro is shown in Figure 3.
Figure 3
Software Resources
For this lab, download the following repositories from GitHub:
- CSP: The following table shows the summary of contents.
| Folder | Description |
|---|---|
| apps | Example applications for CSP library components |
| arch | Initialization and starter code templates and data |
| docs | CSP library help documentation |
| peripheral | PLIB templates and configuration data |
- CORE: The following table shows the summary of contents.
| Folder | Description |
|---|---|
| apps | Example applications for core library components |
| config | Core module configuration scripts |
| docs | Core module library help documentation |
| driver | Core module peripheral device drivers |
| osal | MPLAB Harmony Operating System Abstraction Layer |
| system | MPLAB Harmony system services |
| templates | Application and system file templates |
- You will use the MCC Content Manager to download the above repositories from GitHub.
Overview
This lab shows you how to create an MPLAB Harmony v3 project from scratch, to configure and generate:
- Harmony v3 Peripheral Libraries code for the TC, I²C, USART, DMA, and PORTS peripherals
- Harmony v3 Driver code for the I²C and USART peripherals
- Harmony v3 System Service code for the timer peripheral
It demonstrates the reading of temperature sensor values from the temperature sensor available on the I/O1 Xplained Pro Extension Kit periodically and displays it on a serial console. It further writes the temperature readings to EEPROM. When a character is entered on the console, the last five written temperature values are read from the EEPROM and displayed on the console. Also, an LED is toggled every time the temperature is displayed on the serial console.
The application is divided into two tasks: the Sensor task and the EEPROM task. Each runs its state machines. The Sensor and the EEPROM tasks are called from SYS_Tasks routine which is run in a while (1) loop.
Figure 4
After the initialization of the I²C sensor client and USART driver, the sensor task waits for the one-second periodic timer event. On every one-second periodic timer event, the sensor task submits a temperature sensor read request through the I²C interface. When a temperature sensor read is completed, the application submits a USART write request to transfer the read temperature values to a serial terminal on a PC, at the same time, the sensor task notifies the EEPROM task to store the read temperature value in the EEPROM.
Figure 5
After the initialization of the I²C EEPROM client, the EEPROM task submits a USART read request to receive any user input. Parallelly, for every notification from the sensor task to store the values in the EEPROM, the EEPROM task writes the value to the EEPROM. When user input is received (as a character from the serial terminal on the PC), the EEPROM task submits an I²C request to read the stored (last five) temperature values. When the EEPROM read is completed, the EEPROM task prints the read temperature values on the serial terminal.
Figure 6
Lab Source Files and Solutions
This ZIP file contains the completed solution project for this lab. It also contains the source files needed to perform the lab as per the following step-by-step instructions (see the "Procedure" section on this page).
The contents of this ZIP file need to be placed in a folder of your choice.
The project location of an MPLAB Harmony v3 project is independent of the location of the MPLAB Harmony Framework path (i.e., you don't need to create or place an MPLAB Harmony v3 project in a relative path under the MPLAB Harmony v3 framework folder).
2. The point above is true because when created, a Harmony v3 project generates all the referred source and header files and libraries (if any) under the Project folder.
Extracting the ZIP file creates the following folders:
getting_started_drv contains the lab solution (in the firmware folder) and source files (in the dev_files folder).
- dev_files contains subfolder sam_e70_xult containing application source files and other support files (if any) required to perform the lab (see "Procedure" section below).
- firmware contains the completed lab solution project. It can be directly built and downloaded on the hardware to observe expected behavior.
Procedure
Lab Index
Step 1: Create Project and Configure the SAM E70
- Step 1.1 - Create an MPLAB Harmony v3 with drivers and systems services on sam devices using MPLAB X IDE
- Step 1.2 - Verify Clock Settings
Step 2: Configure I²C, USART Drivers and Timer System Service
- Step 2.1 - Configure Timer System Service
- Step 2.2 - Configure I²C Driver and I²C Pins
- Step 2.3 - Configure USART Driver and USART Pins
- Step 3.1 - Configure LED Pin
- Step 3.2 - Rename the Default Main File
- Step 3.3 - Configure Application Tasks
Step 4: Generate Code
Step 5: Add Application Code to the Project
Step 6: Build, Program, and Observe the Outputs