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Getting Started with the DS1840K . . . Getting Started with the DS1840K . . . Kit Instructions and Operating Procedures Description The DS1840K Potentiometer Evaluation Kit provides the hardware and software necessary to evaluate the functions and features of the DS1845, DS1846, DS1847, and the DS1848 potentiometers in a laboratory environment. The user must supply a PC and a 5V power supply terminated with banana plugs (bench supply or modified “wall wart” transformer) for operation of the kit. The DS1840K also provides an oscillator/buzzer circuit that allows you to “hear” the potentiometers. Kit Contents 1. 2. 3. 4. 5. 6. CD with DS1840K software Evaluation board Cable (6-conductor) Product samples DS9123 serial port dongle Documentation (not shown) If you require a product sample of a device not supplied in this kit, please contact the factory or your local sales representative for availability. Contact information can be found at the end of this document. Figure 1. DS1840K Kit Contents 1 of 13 010801 Getting Started with the DS1840K . . . Setting up the Hardware 1. 2. DS1845 Choose a device to evaluate. The DS1840K comes standard with several product samples. Choose the one that you would like to evaluate first. Look for the socket U1 (or U2 if you are evaluating the U1 DS1846) on the DS1840K board. Your board may have been shipped with a device already in the socket, or it may have Pin1 fallen out/shifted during shipping. If the device you would like to evaluate is already in the socket, make sure it is firmly seated. Otherwise match up the pin 1 indicators of the board and device and insert the device into the socket (Figure 2). Connect 5V power supply to board. As usual, the red banana jack is Vcc, and the black jack is ground. Note: if DIP switch 5 is on you may hear the buzzer (depending on your jumper settings). Figure 2. U1 Pin 1 Location Connect the DS9123 serial port dongle to your PC. Now connect the cable (6-conductor) from the DS9123 to the RJ-11 jack of the DS1840K Demo Board. Finally, install the software (next section). 3. 4. 5. 6. Installing the DS1840K Demo Software Please note: In order to maintain compatibility across operating systems, this installation may require you to reboot your PC. 1. Insert the DS1840K CD into your PC. 2. If your CD autoplay is enabled, then simply follow the prompts. Otherwise, if the CD does not automatically start, then run setup.exe from the CD. 3. If you opt not to install the software on your PC, or if your installation failed, you can still run the DS1840K software. The executable DS1840K.EXE is located in: (your CD drive letter):\program files\Dallas Semiconductor\DS1840K\DS1840K.EXE 4. You are now ready to begin evaluating. Skip to the section of the device you would like to evaluate. 2 of 13 Getting Started with the DS1840K . . . Evaluating the DS1845 The DS184X family of digital potentiometers use the Dallas 2-Wire serial interface. Since it is a multidrop interface, address pins are used to give each device on the bus its own unique address. To provide the most flexibility, the DS1840K Demo Board allows you to set the address (A0, A1, and A2) using DIP switches (see Figure 3). A DIP switch (A0, A1, A2, and WP) in the “ON” position grounds the signal. A DIP switch in the “OFF” position, allows a pull-up resistor to pull the signal to Vcc. All of the address signals have an external pull-up resistor, while the Write Protect (WP) signal has an internal pull-up resistor. If the device is “write protected,” then the wiper can not be moved and the memory can not be modified. The default for these first 4 switches is the “ON” position. This corresponds to a device address of 000h and NO write protection. Figure 3. DIP switches The DS1845 contains two non-volatile potentiometers. Pot 0 is a 100 position pot and Pot 1 is a 256 position pot. Valid wiper settings for Pot 0 (located at F9h in the memory map) are from 0 to 63 hex. Pot 1 (located at F8h) is valid from 0 to FF hex. The physical device pins associated with Pot 0 are L0, W0, and H0. The pins for Pot 1 are L1, W1, and H1. Each of the pot terminals can be accessed directly at the “test points” near the front of the board (see Figure 4). Using a multi-meter, the resistance can be measured from these test points (make sure no jumpers are installed on J4 or J5). Measuring from Hx (x being 0 for pot 0, or 1 for pot 1) to Lx you will see the end-to-end resistance of the pot. For a DS1845-010, you would measure 10KOhms. Measuring from Wx to Lx will result in a resistance depending on where the wiper was last set. If you require a ground terminal, you may use either of the black test points labeled GND, even though they lie within the DS1846 area. Depending on your application, you may wish to use the potentiometer as a voltage divider. This is quite simple using the DS1840K Demo Board. J5 is the jumper block for Pot 0. It contains the three pot terminals as well as Vcc and GND. This makes it very easy to add a jumper between H0 and Vcc, as well as L0 and GND. The result will be a varying voltage between Vcc and GND at the W0 terminal. This same principal can be applied to Pot 1 by using jumper block J4. Figure 4. Potentiometer terminals and jumper blocks. Using either the jumper blocks or the test points, the pots can also be configured as a variable resistor (two terminal device). By shorting Wx to Lx, a variable resistor is made. The resistance can then be measured between Hx and Lx (which is shorted to Wx). Another way to convert the three terminal pot into a 2 terminal variable resistor is by adding jumpers to Lx to GND, and Wx to GND. The resistance can then be measured between Hx and GND. If you use this approach with Pot 0, please be aware that R9 connects H0 to Vcc. This is an error. The ability to jumper the resistor in and out of the circuit will be included in a later revision. The reason why R9 is even necessary is because this board needs to also work with the DS1847/48 variable resistors. 3 of 13 Getting Started with the DS1840K . . . Jumper blocks J4 and J5 are multi-purpose in that they give you the ability to use a ribbon cable to interface the pots to your own circuitry, whether it be in the proto area or elsewhere. The DS1840K Demo Board also contains an oscillator/buzzer circuit which uses the potentiometers to vary the frequency of a tone (see figure 5). The purpose of the buzzer is to allow you to hear the changes in resistance (in case you do not have a multi-meter handy). This circuit is enabled/disabled by DIP switch 5, labeled “555 ON”. To configure the circuit to work with the DS1845, set the three jumpers on JP1 and JP2 as shown in Figure 6 (all three jumpers in the down position). Also, be sure to remove any jumpers on J4 and J5. JP2 H0 CNTRL W0 JP1 H1 555 Vcc W1 Figure 5. Oscillator circuit. L1 DI S L1 Figure 6. Jumper settings. Once you have configured the jumpers and DIP switches to suit your application, you are ready to run the DS1840K Demo Software. Skip over to Using the DS1840K Software. 4 of 13 Getting Started with the DS1840K . . . Evaluating the DS1847/48 The DS1847/48, like the DS1845, also uses the Dallas 2-Wire serial interface. Since it is a multi-drop interface, address pins are used to give each device on the bus its own unique address. To provide the most flexibility, the DS1840K Demo Board allows you to set the address (A0, A1, and A2) using DIP switches (see Figure 3 above). A DIP switch (A0, A1, A2, and WP) in the “ON” position grounds the signal. A DIP switch in the “OFF” position, allows a pull-up resistor to pull the signal to Vcc. All of the address signals have an external pull-up resistor, while the Write Protect (WP) signal has an internal pull-up resistor. If the device is “write protected,” then the resistance cannot be changed and the memory can not be modified. The default for these first 4 switches is the “ON” position. This corresponds to a device address of 000h and NO write protection. The DS1847 and the DS1848 contain two temperature-controlled variable resistors (not potentiometers). Each device offers a temperature-controlled mode, as well as a manual mode. In the temperaturecontrolled mode, there is a look-up table for each pot. Every 10ms a temperature conversion occurs. The most recent result is stored in address locations E2h and E3h. The value of each resistor is then determined by the temperature-addressed look-up table that has a unique (programmed by the user) value for each resistor for every 2C increment over the operating temperature range. For more detailed information, please refer to the datasheet. The physical device pins associated with resistor 0 are L0 and H0. Resistor 1 has its own pins L1 and H1. Notice that since these are not potentiometers, there are no wiper pins. Each of the resistors can be accessed directly at the “test points” near the front of the board (see Figure 4 above). Using a multi-meter, the resistance can be measured from these test points (make sure no jumpers are installed on J4 or J5). Measuring from Hx to Lx you will see a resistance at which the resistor is set. Because the DS1847/48 are not potentiometers, be certain not to install jumpers on J4/J5 that would short either of the variable resistors from Vcc to GND. Jumper blocks J4 and J5 are multi-purpose in that they give you the ability to use a ribbon cable to interface the pots to your own circuitry, whether it be in the proto area or elsewhere. The DS1840K Demo Board also contains an oscillator/buzzer circuit which uses the resistors to vary the frequency of a tone (see figure 5 above). The purpose of the buzzer is to allow you to hear the changes in resistance (in case you do not have a multi-meter handy). This circuit is enabled/disabled by DIP switch 5, labeled “555 ON”. To configure the circuit to work with the DS1847/48, set the three jumpers on JP1 and JP2 as shown in Figure 7 (all three jumpers in the up position). Also, a jumper is needed on J5 to short L0 to GND. JP2 H0 CNTRL W0 JP1 H1 555 Vcc W1 L1 DI S L1 Figure 7. Jumper settings. Once you have configured the jumpers and DIP switches to suit your application, you are ready to run the DS1840K Demo Software. Skip over to Using the DS1840K Software. 5 of 13 Getting Started with the DS1840K . . . Evaluating the DS1846 Note: Before experimenting with the DS1846, it may be necessary to acquire device samples and a socket. Some kits may not have been shipped with these components due to availability at the time of packaging. The required socket is a Wells 676-320 (see figure 8). Please contact the factory for more information. Contact information can be found at the end of this document. The DS1846 also uses the Dallas 2-Wire serial interface. Since it is a multi-drop interface, an address pin on each device gives the ability to assign each device on the bus a unique address. However, the DS1846, unlike the other featured pots, only provides one address pin, A0. To provide the most flexibility, the DS1840K Demo Board allows you to set A0 using DIP switch 7 (see Figure 3 above). Likewise, a DIP switch is also provided for WP (DIP switch 8). A DIP switch in the “ON” position grounds the signal. A DIP switch in the “OFF” position, allows a pull-up resistor to pull the signal to Vcc. The address signal (A0) has an external pull-up resistor, while the Write Protect (WP) signal has an internal pull-up resistor. If the device is “write protected,” then the wiper can not be moved and the memory can not be modified. The default DIP switch settings for the DS1846 are both “ON” (switch 7 and 8). This corresponds to a device address of 0h and NO write protection. Figure 8. DS1846 Socket. The DS1846 contains three non-volatile potentiometers, memory, and a MicroMonitor. The physical device pins associated with each pot are Lx, Wx, and Hx, where x is either 0, 1 , or 2. Each of the pot terminals can be accessed directly at the “test points” near the front of the board (see Figure 9). Using a multi-meter, the resistance can be measured from these test points (make sure no jumpers are installed on J7, J8, or J9). Measuring from Hx to Lx you will see the end-toend resistance of that particular pot. Likewise, measuring from Wx to Lx will result in a resistance depending on where the wiper was last set. Figure 9. DS1846 jumpers and test points. In addition to features similar to the other digital potentiometers, the DS1846 also provides a MicroMonitor. J6 provides easy access to the MicroMonitor signals. Likewise, test points are also provided for these extra signals. For more information regarding the MicroMonitor, please refer to the DS1846 datasheet. 6 of 13 Getting Started with the DS1840K . . . Using the DS1840K Software Before starting the DS1840K Software, make sure that a device is properly installed and that power is applied to the banana jacks. Also, be certain that the serial port dongle (DS9123) and cable are connected. To start the application, go the Start menu and select: Start\Programs\Dallas Semiconductor\DS1840K Kit\DS1840K Or, if you chose not to install, look for the executable named DS1840K.EXE and double click it. When the following dialog box appears (Figure 10), simply choose the device that you would like to evaluate and click “OK”. Figure 10. DS1840K device selection dialog box. The DS1840K Kit Software finally appears. The first item to look for is the status in the lower left corner. If the DS9123 (connected to the serial port) is found, then the text should read “DS9123 ready!”. LED2 on the board should also be illuminated. LED2, if lit, indicates that the serial port is now open. If the status box displays “DS9123 not found!”, then click on the radio button next to “COM2”. Then click “Apply”. If the status box displays “DS9123 ready!”, you are ready to continue. Otherwise, if you are still experiencing difficulties, refer to the “Troubleshooting” section of this document. The kit software is based on Windows property sheets. The first “page” that appears is the General page (see Figure 11). This page is common to all of the DS184X devices. In addition to the status box already discussed, the General page also contains the “Serial Port Settings” options. If you ever need to change the COM port, do not forget to click on “Apply” so the changes will take affect. In the “Serial Port Settings” box you will also find a Test Port button. This button is only necessary for diagnosing serial port and DS9123 problems. The General page also contains the selection for the 2-Wire Slave Address. This address needs to match the DIP switches for A0, A1, and A2. The default of the Figure 11. DS1840K General page. Slave Address is 000, which matches the default DIP switch settings. The last option found on the General page is the Enable LED1 checkbox. While LED2 indicates that the serial port is open, LED1, if checked, 7 of 13 Getting Started with the DS1840K . . . illuminates when data passes from the software to the demo board. LED1 is disabled by default because it slows down the communication considerably. Property pages that follow behind the General tab will vary depending on which device you are evaluating. Figure 12 shows a typical “Pots” page (DS1845 in this case). The pots page is probably where you will be doing the majority of your evaluation. The “Pots” page groups the controls for each pot. Each pot can be modified in three ways: with the edit box, the spin control, or the slider control. Secret: the pots can also be set/read using the memory page discussed later. The easiest way to move the pot is by using the edit box. Simply click on the edit box, type a decimal value in the appropriate range, and click on “Write to Pot”. To read the pot setting, click on “Read Pot”. Another way to move the pot is by using the spin control (up/down arrows). Click up or down until you reach the desired value. Then click on “Write Pot”. The most fun method, however, is using the slider control. Drag the slider the desired position and release. The value of the slider will be sent to the pot when you release the mouse button. Also, once a slider is selected, you can use the keyboard to move it as well. For even more excitement, enable the oscillator circuit (DIP switch 5) and listen to the tone change as you modify the pots. Figure 12. Typical “Pots” page. Another common page is the “Memory” page. The Memory page can be used to read and write data to the EEPROM. The “Page Mode” allows you to read/write memory one page at a time (8 bytes). The “Byte Mode”, as its name suggests, allows you to read/write one byte at a time. For fun, try reading F8 and F9. These are the addresses of Pot 1 and Pot 0, respectively. Figure 13. Memory page. 8 of 13 Getting Started with the DS1840K . . . The “2-Wire” page gives you direct access to 2-Wire communication (see Figure 14). Hopefully, you will never have to use this page. Its main purpose is for debugging. This page also allows you to change the Slave Address. This is the same as the control found on the “General Page”. You may use either one to choose the address. Once again, make sure that this value matches the DIP switch settings. The default value is 000. Figure 14. 2-Wire page. The “DS1847/48” page allows you to display the current temperature, as well as the corresponding resistor values from the lookup tables. In addition, a fill tool is provided to simplify programming of the lookup tables. If you have no particular data to fill the tables with, but would still like to experiment with the operation, you may fill resistor 0 and resistor 1 with ramps. The resistor 0 ramp button fills the lookup table with increasing values starting from 0. Resistor 1 similarly generates a ramp in the opposite direction, starting from a large number and decreases value as address increases. Figure 15. DS1847/48 page. 9 of 13 Getting Started with the DS1840K . . . The DS1847/48 memory page is almost identical to the DS1845 memory page (see Figure 16). The only difference is the addition of the Table Select option. Before reading or writing any memory, be certain that you have selected the memory which you intend to read or write. The DS1847 only has two “memories”, these being the lookup table for Resistor 0 and the lookup table for Resistor 1. The DS1848, however, has both lookup tables, as well as a user EEPROM. Figure 16. DS1847/48 Memory page. Proto Area In order to provide the most flexibility, the DS1840K demo board includes a proto area (see Figure 17). Located in the upper right corner is 20 by 12 grid in which you can add your own circuitry. Power and ground are conveniently located at each edge of the proto area. Figure 17. Proto Area. 10 of 13 Getting Started with the DS1840K . . . DS1840K Demo Board Schematic Figure 17. DS1840K Demo Board Schematic. 11 of 13 Getting Started with the DS1840K . . . Inside the DS9123 Serial Port Dongle Figure 18. DS9123 Schematic. Check our FTP site for more DS9123 information to be added soon. Contact information can be found at the end of this document. 12 of 13 Getting Started with the DS1840K . . . Contact Information For questions, comments, or suggestions pertaining to this demo kit, please contact: [email protected], [email protected], or [email protected]. World Wide Web Site: www.dalsemi.com Ordering Information: www.dalsemi.com/products/ordering.pdf FTP Site: ftp://ftp.dalsemi.com/pub/system_extension/pots/ Datasheets: www.dalsemi.com/datasheets/pdfindex.html Package/Mechanical Drawings: www.dalsemi.com/datasheets/mechdwg.html Product Literature: (972) 371-4448 Sales and Customer Service: (972) 371-4969 Dallas Semiconductor 4401 S. Beltwood Parkway Tel: (972) 371-4448 Fax: (972) 371-4799 13 of 13