PICDEM Touch Sense 2 Demo Board User’s Guide
DS51748A-page 16
©
2008 Microchip Technology Inc.
The global limit area allows the minimum and maximum values for all of the bar graphs
to be globally set manually. The values must be in the range from 0 to 65535. Enter a
value in the text box and press <Enter> for the value to take effect. Notice that changing
this setting overrides any auto-scaling that has been performed.
The
Enable Polling
checkbox enables communication with the PICDEM Touch Sense
2 Demo Board and the real-time display of sensor information. The USB portion of the
mTouch sensing solution remains operational and communicating with the demo board
even when the box is unchecked. If the checkbox is unselected, the last polled values
from the board remain on the bar graphs until
Enable Polling
is selected again; the
latest data is displayed at that time, and normal polling resumes. This makes the
checkbox useful as a “Freeze” or pause button.
The “Trip & Guardband” section configures the interaction between the mTouch
sensing solution and Touch Sense 2 Demo Board with regards to guardband and trip
point settings. There are two option buttons:
•
Default to Firmware Values
enables the trip and guardband values to be
calculated by the demo board’s firmware, using an algorithm that calculates the
optimum trip and guardband values based on the average value. These values
are sent to the mTouch sensing solution tool via the USB connection, and are
constantly updated and displayed on the bar graphs; this is enabled by default.
•
Use Saved Values
enables the values entered into the mTouch sensing solution
to be sent to and used by the demo board via USB. The trip and guardband
values set by the mTouch sensing solution by user input are static, and only
change when the user changes them.
The “Retention” area of the Settings subwindow determines how these settings of the
mTouch sensing solution are saved:
• Global minimum and maximum limits for bar graphs
• Auto-scaling settings
• Trip and guardband settings
• Aux1 and Aux2 settings
When the
Save Settings When Finished
checkbox is selected (default), all of the
above settings are saved to permanent storage on the PC when the mTouch sensing
solution is closed. Clicking the
Save Settings Now
button immediately saves all of the
above values to permanent storage on the PC. In both cases, all settings are restored
when the application is restarted.
Leaving
Save Settings When Finished
unselected allows users to save working
configurations at their discretion by using the
Save Settings Now
button. This allows
for experimentation with the ability to return to “known good” settings by quitting the
mTouch sensing solution and restarting it.
3.2.2.2
INDIVIDUAL SENSOR DISPLAY SETUP
In addition to global display settings, each of the sensor channels can be individually
configured to adjust its behavior, as well as specific display properties. To do this,
left-click directly on top of any channel’s bar graph; the Setup dialog box for that
channel appears (Figure 3-5).
Clicking on another channel while a Setup dialog is open does not close the original
window or open a second Setup dialog. Instead, the dialog box becomes the Setup
dialog for the channel most recently selected.
