STEVAL-ICB007V1
Capacitive touch demonstration board based on the STMPE321
Data brie
Description
The STEVAL-ICB007V1 demonstration board
employs STM32-based capacitive touch to
demonstrate the functionality and performance of
the STMPE321, a 3-channel capacitive touch key
controller.
Capacitance measurement is implemented in
fully optimized hardware, and the 3 I/Os can be
configured as either capacitive touchkeys or as
GPIOs (general purpose input/output). The
device is capable of interfacing with a main digital
ASIC/controller through the 2-line communication
protocol I2C.
Features
• STM32 microcontroller is used as the
main digital controller to interface the
STMPE321 device
• STMPE321 device controls 3 different
touch keys
• Touch events are indicated on the LEDs
• RoHS compliant
In the STEVAL-ICB007V1 demonstration board,
the STM32 microcontroller is used as the main
digital controller to interface with the STMPE321
device. The system utilizes the capacitive
touchkey controller of the STMPE321 and PWM
features of the STM32 to demonstrate the
application.
The STMPE321 controls 3 different touchkeys
using an integrated capacitive touch controller.
Touch events are indicated on the LEDs using
the STM32 GPIO pins, and the corresponding
PWM frequency is generated on a separate LED
using the STM32 timer.
June 2011 DocID018907 Rev 1.0 1/4
For further information contact your local STMicroelectronics sales
office.
www.st.com
Circuit schematic STEVAL-ICB007V1
1 Circuit schematic
SCL
10KR310K
R3
SDA
C2
22pFC222pF
DNMDNM
R5
4.7KR54.7K
DNM
R7
PB1_TIM3 _CH4
R10
R10
220
220
LEDD4LED
CN3
CN3
CN2
CN2
10KR710K
123456789
123456789
C1
R2
10KR210K
3V3
CN1
CN1
DNM DNM
RST
R130R13
0
DNM
PB13_TIM1_CH1N
3V3
SDA
1 2
3 4
GND
INT
PB1_TIM3_CH4
HEADER5X2
HEADER5X2
5 6
7 8
9 10
PB15_TIM1_CH3N
PB0_TIM3_CH3
INT
3V3
22pFC122pF
PB13_TIM1_CH1N
PB15_TIM1_CH3N
R8
R4
220R4220
D2
D1
LEDD1LED
3V3
CREF
5pF
CREF
5pF
3V3 1V8
PB0_TIM3 _CH3
220R8220
R9
220R9220
LEDD2LED
D3
LEDD3LED
D4
C8
100nFC8100nF
INT
101112131415161718192021222324252627282930
1011121314151617181920212223242526272829
CON30
CON30
CON30
CON30
30
DNM
R12
10K
R12
R1
10K
4.7KR14.7K
RST 1V8 SCL
R61KR6
1K
NC
10
INT
11
RST
12
U1
CON1
CON1
1
BUTTON C
BUTTON C
CON2
CON2
1
BUTTON B
BUTTON B
CON3
CON3
1
BUTTON A
BUTTON A
1V8
8
9
VCC
SREF
S21S12S0
GND
7
3
SCL
GND
SDA
6
5
NC
4
STMPE3 21U1STMPE3 21
C5
5pFC55pF
C4
5pFC45pF
DNM DNM DNM
C3
5pFC35pF
2/4 DocID018907 Rev 1.0
F
C9
100nFC9
100n
1V8
V8
1
5
OUT
IN1GND2INHIB IT
U2
3V3GND
GND
C7
1uFC71uF
F
C6
10uFC6
10u
C10
10nF
C10
10nF
4
BYP ASS
LD2985BM18R_SOT23-5LU2LD2985BM18R_SOT23-5L
3
R11
10k
R11
10k
3V3
AM09289V1