ST STMPE2401, Руководство пользователя, Страница: 9 / 22

UM0300 Running the STMPE2401 port expander demo board
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2 Running the STMPE2401 port expander demo board
This Port Expander demo board consists of two main parts:
● PC GUI
●
Demonstration board.
Again in Stand alone mode, the demonstration board can be used without PC GUI.
Before using the demo board in either standalone or PC GUI mode, we need to do following
jumper settings-
● Connect JP1 and JP2 to the I
2
C side (Left Side).
●
Connect JP3 to the Left side to use external crystal oscillator
● Connect JP4 to the power supply you want to use.
2.1 Running in standalone mode
With in a few seconds after you plug in the power supply, a welcome message should come
on LCD and this means that the demo has started correctly.
After that you will see a series of messages coming on the LCD screen. At the end, you will
see a blank LCD screen and you will see all the LEDs blinking. These LEDs are the output
of the 6 PWM outputs coming from 2 STMPE2401 devices. Now the system is ready to be
used.
Again if you find that no message is coming on the LCD after giving the power supply.
Remove the power supply and plugged in again and then observe. You should now see the
message coming on the LCD. If this does not happen even after removing and plugged in
the power supply several times, you need to contact technical support.
2.1.1 PWM Output demo
You can observe the PWM out on the CRO by connecting the probe at the corresponding
LED output (there are 6 LED available in the demo board corresponding to each PWM). In
stand-alone mode the PWM output are pre-programmed and can not be changed.
2.1.2 Keypad demo
As mentioned in the Figure 10 , there is a 4 x 4 normal keypad available on the demo board.
You can observe the key press event on the 16x2 LCD interface. You can observe at most 2
simultaneous key press events. For a case when you press more than 2 keys
simultaneously only first 2 keys press will be detected. All key press events are displayed in
LCD screen.