Achieve a secure and efficient way to store sensitive data using AT24CM02 and STM32F205RB
Store. Retrieve. Repeat.
Published Aug 23, 2023
Click board™
EEPROM 3 click
Dev Board
UNI Clicker
Compiler
NECTO Studio
MCU
STM32F205RB
Our solution leverages EEPROM memory for seamless integration of over-the-air updates, simplifying software deployment and enhancing the agility of your technology
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Hardware Overview
How does it work?
EEPROM 3 Click is based on the AT24CM02, an I2C serial EEPROM from Microchip. The EEPROM density is usually expressed in bits, so exactly 2,097,152 bits are organized in units or words of 8 bits, which gives 262,144 bytes of data memory. Furthermore, the EEPROM is organized in so-called pages. One page holds 256 bytes, and there are 1024 pages (1024 pages x 256 bytes = 262,144 bytes total). Having insight into how the memory cells are organized is important for Write and Erase operations. One of the key features of the
AT24CM02 IC is the Error Detection and Correction scheme (EDC), which allows error correction by utilizing six additional bits internally assigned to a group of four bytes. This protection scheme can correct some types of bit errors, staying transparent to the end user. The bit comparison and error correction are done internally. EEPROM 3 Click uses a standard 2-Wire I2C interface to communicate with the host MCU, supporting clock speeds of up to 1MHz. The I2C address can be selected over the ADD jumper, where 1 is set by
default. Several read modes are available, including current address read, random address read, and sequential address read. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the PWR SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. Also, this Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used as a reference for further development.
Features overview
Development board
UNI Clicker is a compact development board designed as a complete solution that brings the flexibility of add-on Click boards™ to your favorite microcontroller, making it a perfect starter kit for implementing your ideas. It supports a wide range of microcontrollers, such as different ARM, PIC32, dsPIC, PIC, and AVR from various vendors like Microchip, ST, NXP, and TI (regardless of their number of pins), four mikroBUS™ sockets for Click board™ connectivity, a USB connector, LED indicators, buttons, a debugger/programmer connector, and two 26-pin headers for interfacing with external electronics. Thanks to innovative manufacturing technology, it allows you to build
gadgets with unique functionalities and features quickly. Each part of the UNI Clicker development kit contains the components necessary for the most efficient operation of the same board. In addition to the possibility of choosing the UNI Clicker programming method, using a third-party programmer or CODEGRIP/mikroProg connected to onboard JTAG/SWD header, the UNI Clicker board also includes a clean and regulated power supply module for the development kit. It provides two ways of board-powering; through the USB Type-C (USB-C) connector, where onboard voltage regulators provide the appropriate voltage levels to each component on the board, or using a Li-Po/Li
Ion battery via an onboard battery connector. All communication methods that mikroBUS™ itself supports are on this board (plus USB HOST/DEVICE), including the well-established mikroBUS™ socket, a standardized socket for the MCU card (SiBRAIN standard), and several user-configurable buttons and LED indicators. UNI Clicker is an integral part of the Mikroe ecosystem, allowing you to create a new application in minutes. Natively supported by Mikroe software tools, it covers many aspects of prototyping thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.
Microcontroller Overview
MCU Card / MCU
Type
8th Generation
Architecture
ARM Cortex-M3
MCU Memory (KB)
128
Silicon Vendor
STMicroelectronics
Pin count
64
RAM (Bytes)
65536
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the UNI Clicker as your development board.
Track your results in real time
Application Output
After loading the code example, pressing the "DEBUG" button builds and programs it on the selected setup.
After programming is completed, a header with buttons for various actions available in the IDE appears. By clicking the green "PLAY "button, we start reading the results achieved with Click board™.
Upon completion of programming, the Application Output tab is automatically opened, where the achieved result can be read. In case of an inability to perform the Debug function, check if a proper connection between the MCU used by the setup and the CODEGRIP programmer has been established. A detailed explanation of the CODEGRIP-board connection can be found in the CODEGRIP User Manual. Please find it in the RESOURCES section.
Software Support
Library Description
This library contains API for EEPROM 3 Click driver.
Key functions:
eeprom3_write_byte- This function writes data to the desired registereeprom3_write_page- This function writes given number of data to the desired registereeprom3_read- This function reads data from the desired register.
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 Eeprom3 Click example
*
* # Description
* This application demonstrates the process of reading and writing to the EEPROM.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes EEPROM 3 driver.
*
* ## Application Task
* Writing data to EEPROM, reading that data and displaying it via UART
*
* \author MikroE Team
*
*/
// ------------------------------------------------------------------- INCLUDES
#include "board.h"
#include "log.h"
#include "eeprom3.h"
// ------------------------------------------------------------------ VARIABLES
static eeprom3_t eeprom3;
static log_t logger;
uint8_t text[ 7 ] = { 'M','i','k','r','o','e' };
uint8_t mem_value[ 7 ] = { 0 };
// ------------------------------------------------------ APPLICATION FUNCTIONS
void application_init ( void )
{
log_cfg_t log_cfg;
eeprom3_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.
eeprom3_cfg_setup( &cfg );
EEPROM3_MAP_MIKROBUS( cfg, MIKROBUS_1 );
eeprom3_init( &eeprom3, &cfg );
}
void application_task ( void )
{
eeprom3_write_page( &eeprom3, 0x100, text, 6 );
log_printf( &logger, "Writing Mikroe to EEPROM 3 click\r\n" );
Delay_ms ( 1000 );
eeprom3_read( &eeprom3, 0x100, mem_value, 6 );
log_printf( &logger, "Data read: %s\r\n", mem_value );
Delay_ms ( 1000 );
}
int main ( void )
{
/* Do not remove this line or clock might not be set correctly. */
#ifdef PREINIT_SUPPORTED
preinit();
#endif
application_init( );
for ( ; ; )
{
application_task( );
}
return 0;
}
// ------------------------------------------------------------------------ END
