Datasheet

Program Description
3-10
3.4.3 Touch Screen and Analog Inputs
Terminal block J4 provides input connection points for the battery and auxiliary
inputs. Battery input can range from 0 V to 6 V, and the auxiliary inputs can
range from 0 V to V
REF. The touch screen can be connected to J3 or to the J1
terminal block.
Each of these seven inputs has a provision for an RC filter to be placed in line
with the signal. As shipped, all resistors are 0 V, and the capacitors are not
installed. If noisy conditions prevent obtaining good readings from the
TSC2101, 0.1-µF capacitors can be installed in positions C1 through C7. If
more filtering is required, the 0-V resistors should be unsoldered from the
board and replaced with small resistors. Note that increasing the capacitance
on the touch screen inputs requires increased panel voltage stabilization time
and increased precharge and sense times, thus lowering the available number
of readings per second.
3.4.4 Audio Interface Circuitry
A mono Electret microphone can be connected to J6. This jack provides both
audio and bias connections. Bias for the microphone can be supplied either
from the TSC2101 mic bias circuitry or from an external resistor, R14. R14 is
not installed on the TSC2101EVM, but can be installed by the user. Internal
or external bias is selected by JMP3.
A small onboard microphone is also on the EVM, parallel to the J6. Without an
external electrical microphone, voice can be input to the TSC2101 through this
microphone.
The TSC2101 has a built-in headset interface. J7 is the jack for connection to
the headset where the microphone input is mono and the audio output can be
stereo. The signal to the headset can be dc-decoupled through the capacitors
(C21 and C22) or capless. Note that the switch SW3 must be used according
to the software settings to work either at the CAP mode or the CAPLESS
mode. Refer to the related description in the data sheet.
The audio output can also be connected to a 32-Ω speaker through J8, and
the 8-Ω loud speaker through J9.
Additionally, the cell-phone input/output, and the buzz input, can be connected
to the TSC2101 device through the onboard terminal block J2.
3.5 Program Description
After installing the software for the TSC2101EVM as described in section 2.3,
the user can begin to evaluate and develop with the TSC2101.
3.5.1 Human Interface Screen
The program’s interface is a simple, six-tab interface. Clicking on a tab takes
you to the functions associated with that tab. The program begins on the
Human Interface screen (the default) as shown in Figure 3−1.