Intermediate
30 min

Capture and store critical information without constant power with 48LM01 and PIC18F57Q43

Serial EERAM memory for next-level data agility

EERAM 2 Click with Curiosity Nano with PIC18F57Q43

Published Feb 13, 2024

Click board™

EERAM 2 Click

Dev Board

Curiosity Nano with PIC18F57Q43

Compiler

NECTO Studio

MCU

PIC18F57Q43

Utilize serial EERAM in industrial machinery and automation systems, allowing quick recovery from power interruptions and ensuring minimal downtime and smooth operational continuity

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Hardware Overview

How does it work?

EERAM 2 Click is based on the 48LM01, a 1024-Kbit SRAM with EEPROM backup in each memory cell from Microchip. The user can treat this device as a full symmetrical read/write SRAM with no limits on cell usage. The device handles backup to EEPROM on any power disruption, so the user can effectively view this device as an SRAM that never loses its data. The SRAM is organized as 131,072 x 8 bits with access via the SPI serial interface. The backup EEPROM is invisible and cannot be accessed by the user independently. The 48LM01 includes circuitry that detects VCC dropping below a certain threshold, shuts its connection to the outside environment, and transfers all SRAM data to the EEPROM portion of each cell for safekeeping. When VCC returns, the circuitry automatically returns the data to the SRAM, and the user’s interaction with the SRAM can continue with the same data set. When power is first

applied to the click board™, the VCAP capacitor is charged to VCC through the 48LM01 IC. During normal SRAM operation, the capacitor remains charged, and the device monitors the level of system VCC. If the system VCC drops below a set threshold, the device interprets this as a power-off or brown-out event. The device suspends all I/O operation, shuts off its connection with the VCC pin, and uses the saved energy in the capacitor to power the device through the VCAP pin as it transfers all SRAM data to EEPROM. On the next power-up of VCC, the data is transferred back to SRAM, the capacitor is recharged, and the SRAM operation continues. Besides standard 4-wire SPI lines, 48LM01 has an additional HOLD pin. This pin can be used for transmission suspension to the 48LM01 while in the middle of a serial sequence without retransmitting the entire sequence. It must be held high any time this function is not

being used. Once the device is selected and a serial sequence is underway, the HOLD pin may be pulled low to pause further serial communication without resetting the serial sequence. The 48LM01 is internally organized as a continuous SRAM array for reading and writing, along with a non-volatile EEPROM array that is not directly accessible to the user but can be refreshed or recalled on power cycles or software commands. The SRAM array is continuously addressable, so the entire array can be written without accessing pages. 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.

EERAM 2 Click top side image
EERAM 2 Click bottom side image

Features overview

Development board

PIC18F57Q43 Curiosity Nano evaluation kit is a cutting-edge hardware platform designed to evaluate microcontrollers within the PIC18-Q43 family. Central to its design is the inclusion of the powerful PIC18F57Q43 microcontroller (MCU), offering advanced functionalities and robust performance. Key features of this evaluation kit include a yellow user LED and a responsive

mechanical user switch, providing seamless interaction and testing. The provision for a 32.768kHz crystal footprint ensures precision timing capabilities. With an onboard debugger boasting a green power and status LED, programming and debugging become intuitive and efficient. Further enhancing its utility is the Virtual serial port (CDC) and a debug GPIO channel (DGI

GPIO), offering extensive connectivity options. Powered via USB, this kit boasts an adjustable target voltage feature facilitated by the MIC5353 LDO regulator, ensuring stable operation with an output voltage ranging from 1.8V to 5.1V, with a maximum output current of 500mA, subject to ambient temperature and voltage constraints.

PIC18F57Q43 Curiosity Nano double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC

MCU Memory (KB)

128

Silicon Vendor

Microchip

Pin count

48

RAM (Bytes)

8196

You complete me!

Accessories

Curiosity Nano Base for Click boards is a versatile hardware extension platform created to streamline the integration between Curiosity Nano kits and extension boards, tailored explicitly for the mikroBUS™-standardized Click boards and Xplained Pro extension boards. This innovative base board (shield) offers seamless connectivity and expansion possibilities, simplifying experimentation and development. Key features include USB power compatibility from the Curiosity Nano kit, alongside an alternative external power input option for enhanced flexibility. The onboard Li-Ion/LiPo charger and management circuit ensure smooth operation for battery-powered applications, simplifying usage and management. Moreover, the base incorporates a fixed 3.3V PSU dedicated to target and mikroBUS™ power rails, alongside a fixed 5.0V boost converter catering to 5V power rails of mikroBUS™ sockets, providing stable power delivery for various connected devices.

Curiosity Nano Base for Click boards accessories 1 image

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
SPI Chip Select
PD4
CS
SPI Clock
PC6
SCK
SPI Data OUT
PC5
MISO
SPI Data IN
PC4
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
Data Transfer Pause
PB0
PWM
NC
NC
INT
NC
NC
TX
NC
NC
RX
NC
NC
SCL
NC
NC
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Schematic

EERAM 2 Click Schematic schematic

Step by step

Project assembly

Curiosity Nano Base for Click boards front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Curiosity Nano with PIC18F57Q43 as your development board.

Curiosity Nano Base for Click boards front image hardware assembly
Barometer 13 Click front image hardware assembly
PIC18F57Q43 Curiosity Nano front image hardware assembly
Prog-cut hardware assembly
Curiosity Nano with PICXXX MB 1 - upright/background 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
PIC18F57Q43 Curiosity 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 via Debug Mode

1. Once the code example is loaded, pressing the "DEBUG" button initiates the build process, programs it on the created setup, and enters Debug mode.

2. After the programming is completed, a header with buttons for various actions within the IDE becomes visible. Clicking the green "PLAY" button starts reading the results achieved with the Click board™. The achieved results are displayed in the Application Output tab.

DEBUG_Application_Output

Software Support

Library Description

This library contains API for EERAM 2 Click driver.

Key functions:

  • eeram2_set_on_hold_status - Set On-hold status function

  • eeram2_set_command - Set command function

  • eeram2_set_write_status - Set write status function

Open Source

Code example

This example can be found in NECTO Studio. Feel free to download the code, or you can copy the code below.

/*!
 * \file 
 * \brief Eeram2 Click example
 * 
 * # Description
 * This example demonstrates the use of EERAM 2 click board.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes the driver and enables the click board.
 * 
 * ## Application Task  
 * 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 its content on the USB UART.
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "eeram2.h"

// ------------------------------------------------------------------ VARIABLES

static eeram2_t eeram2;
static log_t logger;

static char demo_data[ 9 ] = { 'M', 'i', 'k', 'r', 'o', 'E', 13 ,10 , 0 };
static char read_data[ 9 ];
static uint8_t check_status;

// ------------------------------------------------------ APPLICATION FUNCTIONS

void application_init ( void )
{
    log_cfg_t log_cfg;
    eeram2_cfg_t cfg;

    /** 
     * 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.

    eeram2_cfg_setup( &cfg );
    EERAM2_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    eeram2_init( &eeram2, &cfg );

    eeram2_set_on_hold_status( &eeram2, EERAM2_HOLD_DISABLE );
    Delay_ms( 100 );

    eeram2_set_write_status( &eeram2, EERAM2_WRITE_ENABLE );
    Delay_ms( 100 );
}

void application_task ( void )
{
    check_status = eeram2_write_continuous( &eeram2, 0x00543210, &demo_data[ 0 ], 9 );

    if ( check_status == EERAM2_ERROR )
    {
        log_printf( &logger, "   ERROR Writing    \r\n" );
        log_printf( &logger, "--------------------\r\n" );
        for ( ; ; );
    }

    log_printf( &logger, "     Writing...     \r\n" );
    log_printf( &logger, "--------------------\r\n" );
    Delay_ms( 100 );

    check_status = eeram2_read_continuous( &eeram2, 0x00543210, &read_data[ 0 ], 9 );

    if ( check_status == EERAM2_ERROR )
    {
        log_printf( &logger, "   Reading ERROR    \r\n" );
        log_printf( &logger, "--------------------\r\n" );
        for ( ; ; );
    }

    log_printf( &logger, " Read data : %s", read_data );
    log_printf( &logger, "--------------------\r\n" );
    
    Delay_ms( 1000 );
}

void main ( void )
{
    application_init( );

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


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

Additional Support

Resources

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