Beginner
10 min

Transform your data storage experience with EM064LX and ATmega328P

Our MRAM memory, your data's secure haven.

MRAM 4 Click with Arduino UNO Rev3

Published Feb 14, 2024

Click board™

MRAM 4 Click

Dev. board

Arduino UNO Rev3

Compiler

NECTO Studio

MCU

ATmega328P

Our MRAM memory solution sets a new standard in data storage technology, combining rapid access speeds with magnetic reliability for a seamless and efficient user experience.

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Hardware Overview

How does it work?

MRAM 4 Click is based on the EM064LX, an industrial STT-MRAM persistent memory from Everspin Technologies. It can deliver up to 400Mbps reads and writes via eight I/O signals with a clock frequency of 200MHz. As this is a persistent memory, byte-level writes and reads do not require erasing. Nonvolatile settings are not reflow protected, which you have to keep in mind. A dedicated 256-byte OTP area outside the main memory is readable and user-lockable, with a permanent lock WRITE OTP command. The EM064LX is capable of chip/bulk and sector erase. Subsector erase is possible in 4KB, 32KB granularity. In addition, the MRAM memory features 16 configurable hardware write-protected

regions plus top/bottom select, program/erase protection during power-up, and CRC command to detect accidental changes to user data. As the EM064LX works at the recommended 1.8V voltage, the MRAM 4 Click is equipped with a BH18PB1WHFV, a CMOS LDO regulator from Rohm Semiconductor. To work with different logic level voltage, this Click board™ comes with a TXB0106, a 6-bit bidirectional level-shifting and voltage translator from Texas Instruments. On board, there are two unpopulated jumpers labeled R5 and R6. The chip select and write protection can be pulled up for further hardware development. MRAM 4 Click uses a standard 4-Wire SPI serial interface to communicate

with the host MCU. You can use write protection functionality over the WP pin. The hardware reset is available over the HLD pin, whereas in the low logic state, the memory will self-initialize and return the device to the ready state. There is an unpopulated R6 resistor for an external pull-up, as this pin shouldn’t be allowed to float. This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. Also, it comes equipped with a library containing functions and an example code that can be used as a reference for further development.

MRAM 4 Click hardware overview image

Features overview

Development board

Arduino UNO is a versatile microcontroller board built around the ATmega328P chip. It offers extensive connectivity options for various projects, featuring 14 digital input/output pins, six of which are PWM-capable, along with six analog inputs. Its core components include a 16MHz ceramic resonator, a USB connection, a power jack, an

ICSP header, and a reset button, providing everything necessary to power and program the board. The Uno is ready to go, whether connected to a computer via USB or powered by an AC-to-DC adapter or battery. As the first USB Arduino board, it serves as the benchmark for the Arduino platform, with "Uno" symbolizing its status as the

first in a series. This name choice, meaning "one" in Italian, commemorates the launch of Arduino Software (IDE) 1.0. Initially introduced alongside version 1.0 of the Arduino Software (IDE), the Uno has since become the foundational model for subsequent Arduino releases, embodying the platform's evolution.

Arduino UNO Rev3 double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

AVR

MCU Memory (KB)

32

Silicon Vendor

Microchip

Pin count

28

RAM (Bytes)

2048

You complete me!

Accessories

Click Shield for Arduino UNO has two proprietary mikroBUS™ sockets, allowing all the Click board™ devices to be interfaced with the Arduino UNO board without effort. The Arduino Uno, a microcontroller board based on the ATmega328P, provides an affordable and flexible way for users to try out new concepts and build prototypes with the ATmega328P microcontroller from various combinations of performance, power consumption, and features. The Arduino Uno has 14 digital input/output pins (of which six can be used as PWM outputs), six analog inputs, a 16 MHz ceramic resonator (CSTCE16M0V53-R0), a USB connection, a power jack, an ICSP header, and reset button. Most of the ATmega328P microcontroller pins are brought to the IO pins on the left and right edge of the board, which are then connected to two existing mikroBUS™ sockets. This Click Shield also has several switches that perform functions such as selecting the logic levels of analog signals on mikroBUS™ sockets and selecting logic voltage levels of the mikroBUS™ sockets themselves. Besides, the user is offered the possibility of using any Click board™ with the help of existing bidirectional level-shifting voltage translators, regardless of whether the Click board™ operates at a 3.3V or 5V logic voltage level. Once you connect the Arduino UNO board with our Click Shield for Arduino UNO, you can access hundreds of Click boards™, working with 3.3V or 5V logic voltage levels.

Click Shield for Arduino UNO accessories 1 image

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
SPI Chip Select
PB2
CS
SPI Clock
PB5
SCK
SPI Data OUT
PB4
MISO
SPI Data IN
PB3
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
Write Protect
PD6
PWM
Data Transfer Pause
PC3
INT
NC
NC
TX
NC
NC
RX
NC
NC
SCL
NC
NC
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

MRAM 4 Click Schematic schematic

Step by step

Project assembly

Click Shield for Arduino UNO front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Arduino UNO Rev3 as your development board.

Click Shield for Arduino UNO front image hardware assembly
Arduino UNO Rev3 front image hardware assembly
Charger 27 Click front image hardware assembly
Prog-cut hardware assembly
Board mapper by product8 hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
Necto image step 5 hardware assembly
Necto image step 6 hardware assembly
Arduino UNO MCU Step hardware assembly
Necto No Display image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Debug Image Necto Step hardware assembly

Track your results in real time

Application Output

1. Application Output - In Debug mode, the 'Application Output' window enables real-time data monitoring, offering direct insight into execution results. Ensure proper data display by configuring the environment correctly using the provided tutorial.

2. UART Terminal - Use the UART Terminal to monitor data transmission via a USB to UART converter, allowing direct communication between the Click board™ and your development system. Configure the baud rate and other serial settings according to your project's requirements to ensure proper functionality. For step-by-step setup instructions, refer to the provided tutorial.

3. Plot Output - The Plot feature offers a powerful way to visualize real-time sensor data, enabling trend analysis, debugging, and comparison of multiple data points. To set it up correctly, follow the provided tutorial, which includes a step-by-step example of using the Plot feature to display Click board™ readings. To use the Plot feature in your code, use the function: plot(*insert_graph_name*, variable_name);. This is a general format, and it is up to the user to replace 'insert_graph_name' with the actual graph name and 'variable_name' with the parameter to be displayed.

Software Support

Library Description

This library contains API for MRAM 4 Click driver.

Key functions:

  • mram4_memory_write - MRAM 4 memory write function.

  • mram4_memory_read - MRAM 4 memory read function.

  • mram4_block_erase - MRAM 4 block erase function.

Open Source

Code example

The complete application code and a ready-to-use project are available through the NECTO Studio Package Manager for direct installation in the NECTO Studio. The application code can also be found on the MIKROE GitHub account.

/*!
 * @file main.c
 * @brief MRAM 4 Click example
 *
 * # Description
 * This example demonstrates the use of MRAM 4 click board.
 * The demo app writes specified data to the memory and reads it back.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * The initialization of SPI module, log UART, and additional pins.
 * After the driver init, the app executes a default configuration.
 *
 * ## Application Task
 * The demo application writes a desired number of bytes to the memory 
 * and then verifies if it is written correctly
 * by reading from the same memory location and displaying the memory content.
 * Results are being sent to the UART Terminal, where you can track their changes.
 *
 * @author Nenad Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "mram4.h"

static mram4_t mram4;
static log_t logger;

#define STARTING_ADDRESS             0x012345ul
#define DEMO_TEXT_MESSAGE_1         "MikroE"
#define DEMO_TEXT_MESSAGE_2         "MRAM 4 Click"

void application_init ( void )
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    mram4_cfg_t mram4_cfg;  /**< Click config object. */

    /** 
     * Logger initialization.
     * Default baud rate: 115200
     * Default log level: LOG_LEVEL_DEBUG
     * @note If USB_UART_RX and USB_UART_TX 
     * are defined as HAL_PIN_NC, you will 
     * need to define them manually for log to work. 
     * See @b LOG_MAP_USB_UART macro definition for detailed explanation.
     */
    LOG_MAP_USB_UART( log_cfg );
    log_init( &logger, &log_cfg );
    log_info( &logger, " Application Init " );

    // Click initialization.
    mram4_cfg_setup( &mram4_cfg );
    MRAM4_MAP_MIKROBUS( mram4_cfg, MIKROBUS_1 );
    if ( SPI_MASTER_ERROR == mram4_init( &mram4, &mram4_cfg ) )
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    if ( MRAM4_ERROR == mram4_default_cfg ( &mram4 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }
    Delay_ms( 100 );
    
    log_info( &logger, " Application Task " );
    log_printf( &logger, "-----------------------\r\n" );
    Delay_ms( 100 );
}

void application_task ( void )
{
    uint8_t data_buf[ 128 ] = { 0 };
    log_printf( &logger, " Memory address: 0x%.6LX\r\n", ( uint32_t ) STARTING_ADDRESS );
    if ( MRAM4_OK == mram4_block_erase( &mram4, MRAM4_CMD_ERASE_4KB, STARTING_ADDRESS ) )
    {
        log_printf( &logger, " Erase memory block (4KB)\r\n" );
        Delay_ms( 100 );
    }
    
    memcpy( data_buf, DEMO_TEXT_MESSAGE_1, strlen( DEMO_TEXT_MESSAGE_1 ) );    
    if ( MRAM4_OK == mram4_memory_write( &mram4, STARTING_ADDRESS, data_buf, sizeof( data_buf ) ) )
    {
        log_printf( &logger, " Write data: %s\r\n", data_buf );
        Delay_ms( 100 );
    }
    
    memset( data_buf, 0, sizeof( data_buf ) );
    if ( MRAM4_OK == mram4_memory_read( &mram4, STARTING_ADDRESS, data_buf, sizeof( data_buf ) ) )
    {
        log_printf( &logger, " Read data: %s\r\n", data_buf );
        Delay_ms( 3000 );
    }
    log_printf( &logger, " ----------------------------\r\n" );
    
    log_printf( &logger, " Memory address: 0x%.6LX\r\n", ( uint32_t ) STARTING_ADDRESS );
    if ( MRAM4_OK == mram4_block_erase( &mram4, MRAM4_CMD_ERASE_4KB, STARTING_ADDRESS ) )
    {
        log_printf( &logger, " Erase memory block (4KB)\r\n" );
    }
    
    memcpy( data_buf, DEMO_TEXT_MESSAGE_2, strlen( DEMO_TEXT_MESSAGE_2 ) );
    if ( MRAM4_OK == mram4_memory_write( &mram4, STARTING_ADDRESS, data_buf, sizeof( data_buf ) ) )
    {
        log_printf( &logger, " Write data: %s\r\n", data_buf );
        Delay_ms( 100 );
    }
    
    memset( data_buf, 0, sizeof( data_buf ) );
    if ( MRAM4_OK == mram4_memory_read( &mram4, STARTING_ADDRESS, data_buf, sizeof( data_buf ) ) )
    {
        log_printf( &logger, " Read data: %s\r\n", data_buf );
        Delay_ms( 3000 );
    }
    log_printf ( &logger, " ----------------------------\r\n" );
}

void main ( void )
{
    application_init( );

    for ( ; ; )
    {
        application_task( );
    }
}

// ------------------------------------------------------------------------ END

Additional Support

Resources

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