Capacitive Touch BoosterPack Hardware
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Capacitive Touch BoosterPack Hardware
As shown in
Figure 6
and
Table 1
, the Capacitive Touch BoosterPack is a typical capacitive touch
application example for the new MSP430G2xx2 touch-sense enabled I/O pins. The board shows three
different capacitive sensor types: a single button in the middle, a wheel made of four single capacitive
sensors, and a proximity sensor around the edge of the PCB. In addition, there are nine LEDs on the
board to give instant feedback to user interaction. The eight LEDs around the wheel are multiplexed to
increase their number without using too many of the microcontrollers I/O pins. By using a time-shared
signal, only five I/O pins are used to drive all eight LEDs.
Figure 6. Capacitive Sense BoosterPack Hardware
Table 1. BoosterPack Interface
Pin
MSP430 Port
BoosterPack Signal
Description
1
VCC
NC
Supply voltage, not connected to BoosterPack
2
P1.0
LED9
The white center LED
Backchannel UART transmit data output, not connected to
3
P1.1/TXD
NC
BoosterPack
4
P1.2/RXD
NC
Backchannel UART receive data input, not connected to BoosterPack
5
P1.3
LEDx
LED base to drive the eight multiplexed LEDs
6
P1.4
LED1
LED1 positive and LED5 negative drive
7
P1.5
LED2
LED2 positive and LED6 negative drive
8
P2.0
SENS0
Touch-sense proximity sensor
9
P2.1
SENS1
Touch-sense wheel sensor left
10
P2.2
SENS2
Touch-sense wheel sensor down
11
P2.3
SENS3
Touch-sense wheel sensor right
12
P2.4
SENS4
Touch-sense wheel sensor up
13
P2.5
SENS5
Touch-sense center button sensor
14
P1.6
LED3
LED3 positive and LED7 negative drive
15
P1.7
LED4
LED4 positive and LED8 negative drive
16
RST/SBWTDIO
NC
Reset line for SBW JTAG data, not connected to BoosterPack
17
TEST/SBWTCK
NC
Test line for SBW JTAG clock, not connected to BoosterPack
18
P2.6/XOUT
NC
Oscillator output, not connected to BoosterPack
19
P2.7/XIN
NC
Oscillator input, not connected to BoosterPack
20
GND
GND
Supply ground
14
430BOOST-SENSE1 - Capacitive Touch BoosterPack for the LaunchPad
SLAU337A
–
April 2011
–
Revised September 2011
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2011, Texas Instruments Incorporated