Microchip Technology MCP42XX, Руководство пользователя

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MCP42XX PICtail™ Plus Daughter Board User’s Guide
DS51759A-page 26
©
2008 Microchip Technology Inc.
2.4.2.2 DEMO STEPS
The use of the PICkit Serial Analyzer means that wiper pin’s voltage is under direct
control from the PC’s GUI interface and more user experimentation is possible.
TABLE 2-4: DEMO STEPS USING THE PICDEM HPC EXPLORER DEMO
BOARD
Step Action Result
1a Turn on oscilloscope and configure as follows:
• Channel 1 @ 1V/Division (Note 1) —
1b Configure oscilloscope as follows:
• Time-base = 100 µs/Division
(Note 1)
—
2 Configure the MCP42XXDM-PTPLS to the
jumper settings shown in
Figure 2-15
.
—
3 Insert the PICkit Serial Analyzer into the
MCP42XXDM-PTPLS board’s J1 header.
Ensure proper orientation of the PICkit Serial
Analyzer to the J1 Header. —
4 Connect the oscilloscope probes as follows:
• Channel 1 to the VW1 Pad —
5 Plug the PICkit Serial into the PC’s USB port —
6 Plug the PICkit Serial into the
MCP42XXDM-PTPLS board’s J1 connector The MCP42XXDM-PTPLS board is
now powered
7 Start the GUI application See
Figure 2-8
and
8 Select a Baud rate of 9600 See
Figure 2-9
and
Figure 2-10
9 Under Additional Features, select the “Hex”
radial button and then Click on the “Enable CS”
button. This drives the CS signal low. This
Enables the MCP42XX to receive serial com-
mands. See
Figure 2-11
. The button’s text
changes to “Disable CS”
10 Click on the “Advanced” tab The Advanced screen appears, see
Figure 2-12
11 Click on all 6 “Read” buttons See
Figure 2-13
12 In the Volatile Wiper 1 register text box, type a
value that is significantly different then the cur-
rent value. Such as, if the value was 1FFh, type
20h. See
Figure 2-14
13 Click on the associated “Write” button The VW1 voltage (on the oscillo-
scope) changes.
14 Type other values and then click on the “Write”
button to see how the VW1 voltage changes Look on the oscilloscope to monitor
the Wiper 1 voltage after each click of
the “Write” button.
15 In the Wiper 1 text box, type 080h (mid-scale) The VW1 pin should go to AV
DD
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Note 1: A Digital Multi-Meter (DMM) configured to measure voltage may be used instead of
an oscill0scope.