DUAL EE CLICK
PID: MIKROE-3762 Weight: 20 g
Dual EE Click contains two AT24CM02 EEPROM ICs onboard which gives total of 4MB of
memory. Each memory IC can be addressed through the I2C interface with the transfer
speed of 400KHz. This Click board™ offers any kind of temporary or permanent data
storage for various. embedded electronic devices, as well as simple data logging or even
storing various working parameters of a certain module or device. It can also safeguard all
of the sensitive data in case of a particular power cycle and it has many other capabilities.
Dual EE click is supported by a mikroSDK compliant library, which includes functions that
simplify software development. This Click board™ comes as a fully tested product, ready to
be used on a system equipped with the mikroBUS™ socket.
Dual EE click is aimed towards industrial and commercial applications, which require low
voltage and low power operational capabilities. It can be used for any kind of temporary or
permanent data storage for various embedded electronic devices, simple data logging,
storing various working parameters of a module or device, safeguarding the sensitive data
in case of a power cycle, and other similar applications where EEPROM memory is needed.
HOW DOES IT WORK?
Dual EE Click contains 2 EEPROM ICs onboard – the AT24CM02, an I2C serial
EEPROM from Microchip. This means that the Ics can have a different I2C address so
that users can actually choose which one they would like to use at a particular time.
This is achieved by wiring the I2C address selection lines from one of the Ics to the vcc,
while the other IC is wired to the gnd. Given this feature, it is important to note that this
click board has a total of 4 MB of memory.
This Click board™ uses the I2C communication protocol. Therefore, every data
transaction event is initiated by the host MCU, transmitting the I2C START condition,
followed by the AT24CM02 device ID byte. Upon receiving the device ID byte, the
AT24CM02 IC expects two more address bytes, completing the 18bit address word.
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). Given that
this click contains two separate EEPROM Ics this Click board™ has twice as many
memory which equals 4 MB.
Having insight into how the memory cells are organized, is important for Write and
Erase operations. The I2C pins are routed to the mikroBUS™ so the communication is
easy and straightforward. Both 100KHz and 400KHz transfer speeds are supported by
the AT24CM02 IC, as well as the 1MHz Fast Mode Plus (FM+) I2C communication, for
the MCUs with I2C modules that can support that speed.
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 is capable of correcting some
types of bit errors, staying transparent to the end user. The bit comparison and error
correction are done internally.
The Dual EE Click board™ offers a selection between 3.3V and 5V operation, with the
onboard SMD jumper, labeled as PWR SEL. This allows both 3.3V and 5V MCUs to be
interfaced with this Click board™.
The attached device datasheet contains an in-depth explanation of all the mentioned
functions. However, Mikroe provides a library with functions that make the final code
clean and readable, simplifying working with this device. These functions internally
employ the aforementioned communication mechanism and expose only a simple and
clean interface to the user. The provided example code demonstrates the functionality
of these functions. It can be used as a reference point for a custom development.
SPECIFICATIONS
Type
EEPROM
Applications
Any kind of temporary or permanent data storage for various
embedded electronic devices, simple data logging, storing various
working parameters of a module or device, safeguarding the
sensitive data in case of a power cycle, etc.
On-board
modules
AT24CM02 – 2 Mbit (262,144 x 8) EEPROM from Microchip.
Key Features
Data storage, safeguarding sensitive data, 2 EEPROM ICs
Interface
I2C
Click board
size
M (42.9 x 25.4 mm)
Input Voltage
3.3V,5V
PINOUT DIAGRAM
This table shows how the pinout on Dual EE Click corresponds to the pinout on the
mikroBUS™ socket (the latter shown in the two middle columns).
Notes
Pin
Pin
Notes
NC
1
AN
PWM
16
NC
NC
2
RST
INT
15
NC
NC
3
CS
RX
14
NC
NC
4
SCK
TX
13
NC
NC
5
MISO
SCL
12
SCL
I2C Clock
NC
6
MOSI
SDA
11
SDA
I2C Data
Power Supply
3.3V
7
3.3V
5V
10
5V
Ground
GND
8
GND
GND
9
GND
Power Supply
Ground
ONBOARD SETTINGS AND INDICATORS
Label
Name
Default
LD1
PWR
-
JP1
VCC SEL
Left
Description
Power LED Indicator
Power Supply Voltage Selection 3V3/5V, left position
3v3, right position 5v
SOFTWARE SUPPORT
We provide a library for the DualEE Click on our LibStock page, as well as a demo
application (example), developed using MikroElektronika compilers. The demo can run
on all the main MikroElektronika development boards.
Library Description
The library includes functions to write data to memory and read data from memory.
Key functions:
uint8_t dualee_read(uint32_t regAddress, uint8_t *dataBuff, uint8_t nBytes) - Reading data
from memory
uint8_t dualee_write(uint32_t regAddress, uint8_t *dataBuff, uint8_t nBytes) - Writing data
to memory
Examples description
The application is composed of three sections :
System Initialization - Initializes I2C module
Application Initialization - Initializes driver init
Application Task - Reads your command and then execute i
Commands : '+' - increment current address '-' - decrement current address 'r' - read from current
address 'w' - write from current address and then read it
void applicationTask()
{
uint8_t dataReady_;
uint16_t addressTemp;
char receivedData_;
char addressStr[10];
if (inputDone == 1)
{
mikrobus_logWrite( "", _LOG_LINE);
mikrobus_logWrite("Current page address is 0x", _LOG_TEXT);
addressTemp = (pageAddress >> 16) & 0x00FF;
IntToHex(addressTemp, addressStr);
mikrobus_logWrite( addressStr, _LOG_TEXT);
IntToHex(pageAddress, addressStr);
mikrobus_logWrite( addressStr, _LOG_LINE);
mikrobus_logWrite( "", _LOG_LINE);
mikrobus_logWrite( "Enter '+' if you want to increment current address or '‐' if you w
ant to decrement current address", _LOG_LINE);
mikrobus_logWrite( "Enter 'w' write text in current address or 'r' to read from curren
t address:", _LOG_LINE);
mikrobus_logWrite( "", _LOG_LINE);
inputDone = 0;
}
dataReady_ = UART_Rdy_Ptr( );
if (dataReady_ != 0)
{
receivedData_ = UART_Rd_Ptr( );
switch (receivedData_)
{
case '+' :
{
if(pageAddress _DUALEE_ADDRESS_START)
{
pageAddress ‐‐;
}
else
{
mikrobus_logWrite( "Can't decrement address, this is first address!", _LOG
_LINE);
}
inputDone = 1;
break;
}
case 'w' :
{
dualee_textWrite();
inputDone = 1;
break;
}
case 'r' :
{
dualee_textRead();
inputDone = 1;
break;
}
}
}
Delay_ms(1000);
}
Additional Functions :
void dualee_textRead() - Reads current address and logs that data to USBUART
void dualee_textWrite() - Writes on current address, reads that and then logs that data to USBUART
Note :
When you want to stop writing, you need to send '|'
After you read or write something you should set slight delay
The full application code, and ready to use projects can be found on our LibStock page.
Other mikroE Libraries used in the example:
I2C
Conversions
Additional notes and informations
Depending on the development board you are using, you may need USB UART
click, USB UART 2 click or RS232 click to connect to your PC, for development systems
with no UART to USB interface available on the board. The terminal available in all
MikroElektronika compilers, or any other terminal application of your choice, can be
used to read the message.
MIKROSDK
This Click board™ is supported with mikroSDK - MikroElektronika Software
Development Kit. To ensure proper operation of mikroSDK compliant Click board™
demo applications, mikroSDK should be downloaded from the LibStock and installed for
the compiler you are using.
For more information about mikroSDK, visit the official page.
https://www.mikroe.com/dual-ee-click/10-3-19
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