MAX5388EVMINIQU+ Maxim Integrated, MAX5388EVMINIQU+ Datasheet - Page 6

• Manufacturer Part Number: MAX5388EVMINIQU+
• Description: Digital Potentiometer Development Tools MAX5386/88/91/93 Eval Kit
• Manufacturer: Maxim Integrated
• Series: MAX5386, MAX5388r

Specifications of MAX5388EVMINIQU+

• Rohs: yes
• Product: Evaluation Systems
• Tool Is For Evaluation Of: MAX5388
• Resistance: 100 kOhms
• Operating Supply Voltage: 2.6 V to 5.25 V
• Interface Type: 3 Wire, Serial, USB

MAX5388 Evaluation System
sent for the write to potentiometer A (0x00) or potentiom-
eter B (0x01) commands.
The MAX5388 IC uses an 8-bit (MSBs, D7–D0) data byte
to set the wiper position. Refer to the MAX5386/MAX5388
IC data sheet for additional information.
Press the Tab key to select each GUI control. The select-
ed control is indicated by a dotted outline. Using Shift +
Tab moves the selection to the previously selected con-
trol. Buttons respond to the keyboard’s space bar and
some controls respond to the keyboard’s up and down
arrow keys. Activate the program’s menu bar by press-
ing the F10 key and then press the letter of the desired
menu item. Most menu items have one letter underlined,
indicating their shortcut key.
When a number is entered into the edit boxes, it can be
sent to the device by pressing the Enter key. It is also
sent when Tab or Shift + Tab is pressed.
There are two methods for communicating with the EV
kit, through the normal user-interface panel (Figure 1) or
through the advanced user interface available by select-
ing the 3-Wire Interface (Figure 3) utility from the main
program’s Options | Advanced User Interface menu
bar. A window is displayed that allows SPI send/receive
data operations.
On the 3-wire interface tab, the Connection group box
defines the hardware connections of the interface. For
the EV kit, K10 is selected from the Clock (SCK)(SCLK)
drop-down list, K12 from the Data from master to slave
(MOSI)(DIN) drop-down list is disabled, K11 from the
Data from slave to master (MISO)(DOUT) drop-down
list, K9 from the Chip-select (CS) for data framing
drop-down list, and Use standard connections for
high-speed SPI checkbox is checked (see Figure 3).
The Configuration group box allows the user to config-
ure the logic level and data rate. For the EV kit, check
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Simple SPI Commands
Keyboard Navigation
the Send & Receive MSB first checkbox and verify that
the CPOL=1(clock idle high) and CPHA=1(sample 2
edge) checkboxes are unchecked (see Figure 3).
The Send and Receive Data group box allows the
user to send data to the MAX5388. The Data bytes to
be written edit box indicates data to be sent from the
master (microcontroller) to the device (MAX5388). Eight-
bit hexadecimal numbers should be comma delimited.
Press the Send Now button to transmit the data from the
master to the device. Data appearing in the Data bytes
received edit box is data read from the device. The Data
bytes received edit box in the EV kit software always
shows a default value of 0xFF since the MAX5388 does
not send data back to the master.
Note: The SPI dialog boxes accept numeric data in
hexadecimal format. Hexadecimal numbers must be pre-
fixed by $ or 0x. Figure 3 shows a simple SPI write-byte
operation using the included 3-wire interface diagnostics
tool. In this example, the software is sending command
0x01 (write to potentiometer B) and data 0x7F. The data
sequence sets the MAX5388 wiper position to 127.
Problem: Software reports it cannot find the interface
circuit.
• Is the USB cable connected to the MINIQUSB+
• Has Windows plug-and-play detected the board?
• If using an off-board SPI interface, is the power
board?
Bring up Control Panel->System->Device Manager,
and look at what device nodes are indicated for USB.
If there is an Unknown device node attached to the
USB, uninstall it—this forces plug-and-play to try
again.
ground connected to the EV kit ground (GND) at one
of the header J1 pin connections (J1-2, J1-4, J1-6,
or J1-8)?
General Troubleshooting
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