Intermediate
30 min
0

Transform conventional UART/RS232 into 1-Wire® signals with DS2480B and STM32F429ZI

Streamline your data collection with one wire

UART 1-Wire Click with UNI-DS v8

Published Jun 08, 2023

Click board™

UART 1-Wire Click

Development board

UNI-DS v8

Compiler

NECTO Studio

MCU

STM32F429ZI

By utilizing a single data line for communication and choosing this type of conversion (1-Wire to UART), you will perform efficient and reliable data transfer without additional wiring

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Hardware Overview

How does it work?

UART 1-Wire Click is based on the DS2480B, a serial to the 1-Wire® driver from Analog Devices. This IC is designed to interface the UART with the 1-Wire® bus directly. It performs data conversion using independent data rates for both interfaces, allowing standard and overdrive communication speeds. Internal timing generators of the DS2480B IC are continuously synchronized with the incoming UART data, which is typically driven by a high-precision crystal oscillator of the host microcontroller (MCU). This allows time-critical 1-Wire® signals to be generated by the DS2480B, significantly reducing the processing load from the host MCU. Many physical parameters of the UART and 1-Wire® buses can be fine-tuned so that the UART 1-Wire click can be accommodated to any UART/RS232 to 1-Wire® signal conversion application. The DS2480B IC can be observed as a complex state machine. UART commands can configure it, so the IC must parse the

incoming data before conversion. The device can be operated in two main operating modes: Command Mode and Data Mode. The Command Mode is the default state after the Power ON event. This mode allows the configuration parameters to be set. However, the DS2480B IC must be initialized before any operation: the 1-Wire® bus reset command should be sent over the TXD line at a fixed rate of 9600 bps. This is used only to calibrate the internal timing generators without performing any action on the 1-Wire® bus. After the initialization, the DS2480B IC can be used normally. The Data Mode converts bytes received at the TXD line into their equivalent 1-Wire® waveforms and reports the responses back to the host MCU through the RXD line. The datasheet of the DS2480B IC illustrates the operating principles of this IC by using the state transition diagram. Along with several examples at the end of the datasheet, it represents a useful starting point for application

development. However, the included mikroSDK-compatible library offers functions that simplify firmware development even more. The DS2480B requires 5V for both the power supply and logic levels. Considering that most MCUs use 3.3V logic levels for UART communication, a level translator had to be added. UART 1-Wire click uses the TXB0106, a bi-directional level translator IC, by Texas Instruments. This IC allows reliable logic voltage level translation, allowing the Click board™ to be used with a wide range of MCUs that use 3.3V logic levels on their UART lines. The 1-Wire® bus can be accessed over the screw terminal on the Click board™. Due to the nature of most 1-Wire® applications, the signal line of the 1-Wire® bus is protected by the DS9503, an integrated ESD Protection Diode with resistors. This IC is specifically designed to be used as Electrostatic Discharge (ESD) protection in 1-Wire® applications.

uart-1-wire-click-hardware-overview

Features overview

Development board

UNI-DS v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports a wide range of microcontrollers, such as different STM32, Kinetis, TIVA, CEC, MSP, PIC, dsPIC, PIC32, and AVR MCUs regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer over WiFi. The development board is well organized and designed so that the end-user has all the necessary elements, such as switches, buttons, indicators, connectors, and others, in one place. Thanks to innovative manufacturing technology, UNI-DS v8 provides a fluid and immersive working experience, allowing access anywhere and under any

circumstances at any time. Each part of the UNI-DS v8 development board contains the components necessary for the most efficient operation of the same board. An advanced integrated CODEGRIP programmer/debugger module offers many valuable programming/debugging options, including support for JTAG, SWD, and SWO Trace (Single Wire Output)), and seamless integration with the Mikroe software environment. Besides, it also includes a clean and regulated power supply module for the development board. It can use a wide range of external power sources, including a battery, an external 12V power supply, and a power source via the USB Type-C (USB-C) connector. Communication options such as USB-UART, USB

HOST/DEVICE, CAN (on the MCU card, if supported), and Ethernet is also included. In addition, it also has the well-established mikroBUS™ standard, a standardized socket for the MCU card (SiBRAIN standard), and two display options for the TFT board line of products and character-based LCD. UNI-DS v8 is an integral part of the Mikroe ecosystem for rapid development. Natively supported by Mikroe software tools, it covers many aspects of prototyping and development thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.

UNI-DS v8 horizontal image

Microcontroller Overview

MCU Card / MCU

default

Type

8th Generation

Architecture

ARM Cortex-M4

MCU Memory (KB)

2048

Silicon Vendor

STMicroelectronics

Pin count

144

RAM (Bytes)

262144

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
NC
NC
INT
UART TX
PB6
TX
UART RX
PB7
RX
NC
NC
SCL
NC
NC
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Schematic

UART 1-Wire Click Schematic schematic

Step by step

Project assembly

Fusion for PIC v8 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the UNI-DS v8 as your development board.

Fusion for PIC v8 front image hardware assembly
GNSS2 Click front image hardware assembly
SiBRAIN for PIC32MZ1024EFK144 front image hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
v8 SiBRAIN Access 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 Compiler Selection Step Image hardware assembly
NECTO Output Selection Step Image hardware assembly
Necto image step 6 hardware assembly
Necto image step 7 hardware assembly
Necto image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Necto PreFlash Image hardware assembly

Track your results in real time

Application Output

After pressing the "FLASH" button on the left-side panel, it is necessary to open the UART terminal to display the achieved results. By clicking on the Tools icon in the right-hand panel, multiple different functions are displayed, among which is the UART Terminal. Click on the offered "UART Terminal" icon.

UART Application Output Step 1

Once the UART terminal is opened, the window takes on a new form. At the top of the tab are two buttons, one for adjusting the parameters of the UART terminal and the other for connecting the UART terminal. The tab's lower part is reserved for displaying the achieved results. Before connecting, the terminal has a Disconnected status, indicating that the terminal is not yet active. Before connecting, it is necessary to check the set parameters of the UART terminal. Click on the "OPTIONS" button.

UART Application Output Step 2

In the newly opened UART Terminal Options field, we check if the terminal settings are correct, such as the set port and the Baud rate of UART communication. If the data is not displayed properly, it is possible that the Baud rate value is not set correctly and needs to be adjusted to 115200. If all the parameters are set correctly, click on "CONFIGURE".

UART Application Output Step 3

The next step is to click on the "CONNECT" button, after which the terminal status changes from Disconnected to Connected in green, and the data is displayed in the Received data field.

UART Application Output Step 4

Software Support

Library Description

This library contains API for UART 1-Wire Click driver.

Key functions:

  • uart1wire_write_command - This function sends an 8-bit command to the click module.

  • uart1wire_read_temperature - This function reads the temperature from DALLAS one wire temperature sensors.

  • uart1wire_reset - This function sends a reset pulse signal.

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 UART1Wire Click example
 * 
 * # Description
 * This example reads and processes data from UART 1-Wire clicks.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes the driver and logger.
 * 
 * ## Application Task  
 * Reads the temperature data from DALLAS temperature sensors and logs the results
 * on the USB UART every second.
 * 
 * @note
 * Connect only DQ and GND pins to the UART 1-Wire click connector.
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "uart1wire.h"
#include "string.h"

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

static uart1wire_t uart1wire;
static log_t logger;

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    uart1wire_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.

    uart1wire_cfg_setup( &cfg );
    UART1WIRE_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    uart1wire_init( &uart1wire, &cfg );
    
    Delay_ms( 100 );
}

void application_task ( void )
{
    float temp_f;
    uint8_t res_flag;
    
    res_flag = uart1wire_read_temperature ( &uart1wire, &temp_f, UART1WIRE_TEMP_SENSOR_RESOLUTION_9BIT );
    if ( res_flag == UART1WIRE_OK )
    {
        log_printf( &logger, " * Temperature:     %.2f C\r\n", temp_f );
        log_printf( &logger, "------------------------------\r\n" );
        Delay_ms( 1000 );
    }
}

void main ( void )
{
    application_init( );

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

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

Additional Support

Resources