1-Wire Thermal Device Evaluation Kit
Demonstrates the Full Features of the Dallas
1-Wire® Thermal Devices, Including:
Complete Read/Write Access to All Registers
Within the Devices.
Measures Temperatures from the Full Range
of the Devices -55°C to +125°C. Fahrenheit
Equivalent is -67°F to +257°F.
Celsius and Fahrenheit Temperature Reading
and Charting is Provided for All Supported
Interfaces to the Serial Port of a PC Running
Windows® 95 or Newer.
1-Wire Board
Evaluation Kit Contents
Equipment Needed
Setup and Installation
Board Connections
Software Installation
Selecting the Device
Selecting the COM Port
Program Menus
Register Windows
Program Tabs
ROM Code
1 pc. DS1701K 1-Wire Board
1 pc. DS9123 Serial Port Adapter
1 pc. RJ-11 Phone Cable
1 pc. DS1701K CD Containing:
DS1701K Evaluation Software
DS1701K Related Data Sheets
1. A PC Running Windows 95 or Newer with a
CD-ROM Drive and an Available Serial Port
2. A Battery or a Power Supply with Output
Between +3.0V and +5.5
*Kit demonstration boards will vary as they are improved upon over time.
1-Wire is a registered trademark of Dallas Semiconductor.
Windows is a registered trademark of Microsoft Corp.
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The DS1701K evaluation kit makes performance evaluation, software development, and prototyping with
the Dallas 1-Wire thermal devices easy. The evaluation board interfaces to PC through a DS9123 serial
port adapter and RJ-11 cable connection. The provided CD-ROM contains all related data sheets along
with the evaluation software, which can be run under Windows 95 or newer.
The DS1701K evaluation software gives the user complete control of all functions of the Dallas 1-Wire
thermal devices. Separate control tabs allow the user to view the real-time updates of the temperature at
the desired resolution as well as access to all scratchpad and EEPROM memory locations. The software
incorporates a datalogging feature to monitor a device over time. Additionally the software provides the
ability to select and read various devices on the 1-Wire bus.
The Dallas 1-Wire thermal devices can be placed in any or all of the X1 through X5 3-pin sockets and be
soldered into any or all of the U1 through U5 holes. The user can install up to 10 devices on the 1-Wire
bus on this evaluation board and then use the software to select which device to read. See the Device
Select Menu section below. However, make sure there is a maximum of one DS1821 on the bus, because
the DS1821 does not offer the multidrop functionality and will create data collisions if more than one is
on the bus at a time.
Communication to the board can be accomplished by connecting the DS9123 serial port adapter to an
available serial port on a PC. Then connect the RJ-11 jack to the DS9123 serial port adapter with the
provided 6 conductor cable. The DS1701K software can communicate with the Dallas 1-Wire thermal
devices without a power supply being connected to the board. However, temperature readings will not be
performed unless the device is configured in parasite power mode (see device data sheets for information
on parasite power mode.)
To install the DS1701K software, exit all programs currently running and insert the DS1701K software
CD into your computer’s CD-ROM. The user can run SETUP.EXE from the setup directory and the
installation process begins. Follow the prompts to complete the installation. The DS1701K software can
be uninstalled in the Add/Remove Programs tool in the Control Panel. After the installation is complete,
open the DS1701K folder and run DS1701K.EXE or select DS1701K from the program menu. A splash
screen containing information about the evaluation kit appears as the program is being loaded.
The documentation directory, also located on the CD, contains all relevant data sheets and application
notes on the DS18B20, DS18S20, DS1821, DS1822, and DS1701K. They are stored in Adobe Acrobat
format for easy viewing.
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The user will be prompted to select which Dallas 1-Wire thermal device the DS1701K should expect to
find on the DS1701K board. If more than one device is connected, simply select which device will be
initially communicated with, and that selection can be changed while the program is running if necessary
by accessing the Select Device option on the menu bar.
The first time the software runs the Serial Port Settings window appears. In this window, select the COM
port to which the DS9123 is attached and the desired communication rate; then click OK. The DS1701K
software saves this COM port selection and automatically uses the selection each time the program starts.
To change the COM port later, click the Preferences option on the menu bar, select Serial Port Settings,
and then select the appropriate port. To attempt to automatically locate the DS9123, click the Poll Serial
Ports button. Warning—automatically polling for the DS9123 can disrupt other devices connected to
your computer’s COM ports.
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Several pulldown menu options have been provided to simplify use of the DS1701K software for the
user. Their functions are individually detailed below.
The Device Select menu allows the user to select which type of Dallas 1-Wire thermal device will be
read. When one of the devices is selected from the menu, the program will find a device that matches the
ROM Code of the selected device type and begin reading and making calculations based on the new
device selection.
When the DS1821 is the device selected, the Registers menu appears and gives immediate access to the
status/configuration register. See the Status Register window example.
The present state of all register bits are displayed immediately upon opening the register window. R/W
locations contain a selection field to allow the user to determine their state. Pressing the Write button will
write the register with the new value.
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The Mode menu is also only visible when the DS1821 is selected. This allows the user to switch between
the 1-Wire Mode and Thermostat Mode of the DS1821. When entering the Thermostat Mode, the
software will automatically set the power-up operating mode bit of the Status Register and then prompt
the user to “Set VDD to 0V”. When VDD is set to 0V, click OK, and the DQ line will be pulsed 16 times in
order to temporarily enter Thermostat Mode as outlined in the DS1821 data sheet. When exiting
Thermostat Mode, the program will prompt the user to again “Set VDD to 0V”. When that is done, click
OK and DQ will be pulsed 16 times to temporarily enter the 1-Wire Mode and the power-up operating
mode bit of the Status Register is cleared. In order to power-up in the new mode, DQ and VDD should be
low for approximately 10 seconds.
The Resolution menu allows the user to select the resolution of the temperature conversion. The
DS18B20 and DS1822 will produce temperature results in 9-, 10-, 11-, or 12-bit resolution. The DS18S20
allows for 9-bit or a High-Resolution mode. The DS1821 allows for 8-bit or a High-Resolution mode.
When the resolution is changed for the DS18B20 or the DS1822, the resolution bits of the configuration
register will be updated. When the High-Resolution mode is selected for the DS18S20 or the DS1821, the
additional steps, as outlined in the device data sheets, will be taken to appropriately read the Count
Remaining and Count Per °C registers and make the required calculations.
The Preferences menu allows the user to change COM port settings at any time. Edit Preferences opens
the Select Preferences window. See Selecting the COM Port above.
Selecting the About topic from the Help menu will open a window containing information about this
program and Dallas Semiconductor.
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All functions of the program are divided under four tabs in the main program window. Left click on the
appropriate tab to move to the desired function page. Located under the Thermometer tab are all of the
real-time updates of all the registers and the calculated results. The Data Log tab allows the user to log
the data to a file. The Memory tab displays the contents of every register and memory location inside the
Dallas 1-Wire thermal devices and allows the user to alter the data. The ROM Codes tab gives the user the
ability to read all 1-Wire devices on the 1-Wire bus and read any devices with an alarm condition set.
The thermometer screen displays the latest real-time temperature measurement and the TH and TL values
with both analog thermometer readout and digital values. All registers are read and displayed on this
screen. To edit any of the values that can be modified by the user, left-click on the associated label and
the program will go to the Memory tab where the values can be read and written to the scratchpad and
EEPROM. For the DS1821, left clicking on the Configuration register label will open the
Status/Configuration Register window.
For the DS18B20, DS18S20 and DS1822, the user can check the box at the bottom of the window to
perform an Alarm Search routine during each loop to check for any alarm flags that are set by any devices
on the bus. If the selected device has an alarm condition, the alarm LED will be lit. Any devices with an
alarm condition will have its ROM Code displayed on the Alarm Search sub-tab of the ROM Codes tab.
For the DS1821, a Start Convert T command is required to start a temperature conversion. If the device is
in Continuous Mode, sending one Start Convert T command will allow the device to continuously
monitor the temperature in 8-bit resolution. If the device is in 1-Shot Mode, one-temperature conversion,
in either 8-bit or high resolution, will be performed for each Start Convert T command that is sent. Since
the device cannot continuously monitor temperature in high resolution, a check box has been included so
that a Start Convert T command will be automatically sent prior to reading the temperature.
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The Data Log tab allows the user to see the temperature, TH and TL points graphed over time. The graph
displays the last 500 data points collected by the DS1701K software and can be displayed in either °C or
°F. The Clear Graphs button will clear all data from the graph, but does not reset the log to file function.
The Log to File sub-tab contains control information for storing all log data to an ASCII file. The default
filename is c:\DS1701K_datalog.txt, but can be modified in the filename text field. The Log Data button
toggles data logging off and on. Data will be stored at the interval selected in the tab-delimited format of
“Time<tab>Temperature<tab>TH<tab>TL<tab>Alarm Status”
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for easy import into a spreadsheet. The most recent 50 samples are displayed in the window for
observation. Warning—the Log Data function overwrites previous file information. Data previously
stored in the file will be lost unless you change the filename. The sampling interval can be set from 1
second to 15 minutes and can be adjusted from the Sampling Interval menu at the bottom of the window.
The Memory tab allows the user to see all 9 bytes that are read from the DS18B20, DS18S20, and
DS1822. The user also can modify and write the 2 user bytes (TH and TL) and the configuration register.
By left-clicking on the Write button, the scratchpad will be modified with new data, but the EEPROM
values are not updated until the Copy button is pressed. The user can change the TH and TL registers in
one of three formats: in hexadecimal form, in degrees C, or in degrees F. The program will detect which
text box was the last one updated, and write that value to the device.
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For the DS1821, the Memory tab allows the user to read and write the Status/Configuration, TH and TL
registers. The Counter and Slope registers, which are used in calculating the high-resolution temperature,
can also be read.
All of the 1-Wire ROM codes found on the 1-Wire bus will be displayed in this window. The user can
request a new search ROM routine by left-clicking on the Find ROM Codes button in order to find any
new or removed ROM codes on the bus. The user also can select a specific ROM code to read by left
clicking on the desired ROM code. In that event, the program will identify which type of device is
selected and make the appropriate readings and calculations.
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