Enhance industrial device communication with the DS2485 and STM32F091RC
An advanced 1-Wire master with EEPROM memory
Published May 16, 2024
Click board™
I2C 1-Wire 2 Click
Dev. board
Nucleo-64 with STM32F091RC MCU
Compiler
NECTO Studio
MCU
STM32F091RC
Simplify communication by allowing I2C devices to talk to 1-Wire devices easily, especially in industrial settings.
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Hardware Overview
How does it work?
I2C 1-Wire 2 Click is based on the DS2485, an advanced 1-Wire master with memory from Analog Devices. The core function of the DS2485 involves facilitating the protocol transition between the I2C master interface and any connected 1-Wire slave devices. It is equipped with internal, adjustable timers that manage the 1-Wire signaling, thereby offloading the host processor of the duty to produce timing-sensitive 1-Wire signals. This feature allows for both regular and accelerated 1-Wire communication rates. An internal weak pull-up can pull the 1-Wire line up, an external resistor by populating R6 with a chosen resistance value, or combining internal and external pull-up methods for enhanced flexibility. This Click board™ is predominantly utilized in industrial sensor and tool
applications, temporary consumables, and for identifying printer cartridges. Upon receiving commands and data, the DS2485's input/output management unit takes over the execution of crucial 1-Wire operations such as the reset/presence-detection cycle, byte reading and writing, block reading and writing, single-bit read/write operations, executing triplets for ROM search activities, and handling complete command sequences for 1-Wire authenticators—all without the need for continuous host processor intervention. Featuring a 0.75Kb EEPROM array, the DS2485 offers general-purpose, reprogrammable memory distributed across three 32-byte pages at even-numbered addresses, while odd-numbered pages are locked and inaccessible.
Each of these even-numbered pages comes with optional security settings. For communication with the host processor, the DS2485 uses an I2C interface, supporting both standard and fast modes, with communication speeds up to 1MHz. Additionally, the device's general-purpose I/O pin, available on the GPO terminal, can be managed independently via specific commands. 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.
Features overview
Development board
Nucleo-64 with STM32F091RC MCU offers a cost-effective and adaptable platform for developers to explore new ideas and prototype their designs. This board harnesses the versatility of the STM32 microcontroller, enabling users to select the optimal balance of performance and power consumption for their projects. It accommodates the STM32 microcontroller in the LQFP64 package and includes essential components such as a user LED, which doubles as an ARDUINO® signal, alongside user and reset push-buttons, and a 32.768kHz crystal oscillator for precise timing operations. Designed with expansion and flexibility in mind, the Nucleo-64 board features an ARDUINO® Uno V3 expansion connector and ST morpho extension pin
headers, granting complete access to the STM32's I/Os for comprehensive project integration. Power supply options are adaptable, supporting ST-LINK USB VBUS or external power sources, ensuring adaptability in various development environments. The board also has an on-board ST-LINK debugger/programmer with USB re-enumeration capability, simplifying the programming and debugging process. Moreover, the board is designed to simplify advanced development with its external SMPS for efficient Vcore logic supply, support for USB Device full speed or USB SNK/UFP full speed, and built-in cryptographic features, enhancing both the power efficiency and security of projects. Additional connectivity is
provided through dedicated connectors for external SMPS experimentation, a USB connector for the ST-LINK, and a MIPI® debug connector, expanding the possibilities for hardware interfacing and experimentation. Developers will find extensive support through comprehensive free software libraries and examples, courtesy of the STM32Cube MCU Package. This, combined with compatibility with a wide array of Integrated Development Environments (IDEs), including IAR Embedded Workbench®, MDK-ARM, and STM32CubeIDE, ensures a smooth and efficient development experience, allowing users to fully leverage the capabilities of the Nucleo-64 board in their projects.
Microcontroller Overview
MCU Card / MCU
Architecture
ARM Cortex-M0
MCU Memory (KB)
256
Silicon Vendor
STMicroelectronics
Pin count
64
RAM (Bytes)
32768
You complete me!
Accessories
Click Shield for Nucleo-64 comes equipped with two proprietary mikroBUS™ sockets, allowing all the Click board™ devices to be interfaced with the STM32 Nucleo-64 board with no effort. This way, Mikroe allows its users to add any functionality from our ever-growing range of Click boards™, such as WiFi, GSM, GPS, Bluetooth, ZigBee, environmental sensors, LEDs, speech recognition, motor control, movement sensors, and many more. More than 1537 Click boards™, which can be stacked and integrated, are at your disposal. The STM32 Nucleo-64 boards are based on the microcontrollers in 64-pin packages, a 32-bit MCU with an ARM Cortex M4 processor operating at 84MHz, 512Kb Flash, and 96KB SRAM, divided into two regions where the top section represents the ST-Link/V2 debugger and programmer while the bottom section of the board is an actual development board. These boards are controlled and powered conveniently through a USB connection to program and efficiently debug the Nucleo-64 board out of the box, with an additional USB cable connected to the USB mini port on the board. Most of the STM32 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 STM32 Nucleo-64 board with our Click Shield for Nucleo-64, you can access hundreds of Click boards™, working with 3.3V or 5V logic voltage levels.
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Click board™ Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Nucleo-64 with STM32F091RC MCU as your development board.
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 I2C 1-Wire 2 Click driver.
Key functions:
i2c1wire2_master_reset- This function is used to reset device, and return all configuration registers to the default values.i2c1wire2_write_port_cfg- This function is used to write a 1-Wire configuration register.i2c1wire2_search- This function is used to perform 1-Wire Search algorithm and return one device ROMID.
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 I2C 1-Wire 2 Click example
*
* # Description
* This example demonstrates the use of the I2C 1-Wire 2 Click board
* by searching if a device is connected and reading its ROMID.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initialization of I2C module, log UART and perform Click default configuration.
*
* ## Application Task
* Performing 1-Wire Search algorithm to find if any device is connected.
* If a device is connected and detected, its ROMID will be read and displayed.
*
* @author Stefan Ilic
*
*/
#include "board.h"
#include "log.h"
#include "i2c1wire2.h"
static i2c1wire2_t i2c1wire2;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
i2c1wire2_cfg_t i2c1wire2_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.
i2c1wire2_cfg_setup( &i2c1wire2_cfg );
I2C1WIRE2_MAP_MIKROBUS( i2c1wire2_cfg, MIKROBUS_1 );
if ( I2C_MASTER_ERROR == i2c1wire2_init( &i2c1wire2, &i2c1wire2_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
if ( I2C1WIRE2_ERROR == i2c1wire2_default_cfg ( &i2c1wire2 ) )
{
log_error( &logger, " Default configuration." );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
err_t error_flag;
uint8_t flag;
uint8_t last_flag;
uint8_t rom_id[ 8 ] = { 0 };
#define I2C1WIRE2_DEVICE_SEARCH_CODE 0xF0
error_flag = i2c1wire2_search ( &i2c1wire2, &flag, rom_id, &last_flag, I2C1WIRE2_SEARCH_RESET |
I2C1WIRE2_SEARCH_1WIRE_RESET, I2C1WIRE2_DEVICE_SEARCH_CODE );
if ( I2C1WIRE2_OK == error_flag )
{
if ( I2C1WIRE2_RESULT_BYTE_OK == flag )
{
log_printf( &logger, " Device found: \r\n" );
log_printf( &logger, " Device ROMID: 0x" );
for ( uint8_t n_cnt = 0; n_cnt < 8; n_cnt++ )
{
log_printf( &logger, "%.2X", ( uint16_t ) rom_id[ n_cnt ] );
}
log_printf( &logger, " \r\n" );
log_printf( &logger, " Last device flag %d \r\n", last_flag );
}
else if ( I2C1WIRE2_NO_DEVICE_DETECTED == flag )
{
log_printf( &logger, " No device detected \r\n" );
}
else if ( I2C1WIRE2_NO_PRESENCE_PULS == flag )
{
log_printf( &logger, " No presence puls \r\n" );
}
}
else
{
log_printf( &logger, " ERROR \r\n" );
}
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
