TWR-K60N512-KEIL Freescale Semiconductor, TWR-K60N512-KEIL Datasheet - Page 163

• Manufacturer Part Number: TWR-K60N512-KEIL
• Description: K60N512 Keil Tower Kit
• Manufacturer: Freescale Semiconductor
• Series: Kinetisr
• Type: MCUr

Specifications of TWR-K60N512-KEIL

• Rohs Compliant: YES
• Contents: 4 Boards, Documentation, DVD
• Peak Reflow Compatible (260 C): Yes
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: Freescale Tower System, K60N512

The most relevant part of initialization is enabling the module after configuration. In this
application, after initial configuration the TSI_SelfCalibration() is called. This function
performs a single scan at the beginning of the program to determine a baseline or
"untouched" value for the electrodes. In this application the baseline value and the touch
value are stored in separate data arrays. The touch value is equal to the baseline value of
each electrode plus a delta value. This delta value must be below the touch value, but
above the noise level of the untouched electrode. By debugging, an ideal delta value is
determined. It is always best to keep this delta value as high as possible, but low enough
that all touches are detected.
Notice that the TSI_SelfCalibration() function performs a single scan and waits for the
scan to finish and the values to be updated in the registers. The calibration function also
disables the TSI module afterwards, so that the following code enables the module as
needed. During application time, the TSI is interrupt driven. See
This application is specifically designed to show the small amount of code and CPU
resources that are required to track touches with the TSI. For advanced HMI functionality
Freescale provides the Touch Sensing Software (TSS) library free of charge. This library
provides, basic touch sensing, and advanced API for HMI functions like multiple key
detection, grouping of controls like keypads, sliders, and rotaries. It also implements
advanced filtering and automatic baseline tracking, providing further robustness to the
measurements. Also, included is the standard GPIO-based sensing method, if 16
electrodes are not enough, GPIO pins can be used to provide even more touch sensors.
For more info on the TSS library and downloads visit www.freescale.com/touchsensing.
Freescale Semiconductor
TSI Initialization
TSI Self calibration
Start continuous
scanning
Kinetis Quick Reference User Guide, Rev. 0, 11/2010
Figure 17-5. Application start-up procedure
Enable end of
scan interrupt
Enable TSI
module
Chapter 17 Touch Sense Input (TSI) Module
Figure 17-5
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