Moxa DA-662A-I-8-LX [59/63] Keypad

DA-662A Series Software Programmer's Guide

5-12

int ioctl(fd, IOCTL_LCM_BACK_LIGH_ON, NULL);

Turns the LCM backlight on.

int ioctl(fd, IOCTL_LCM_BACK_LIGHT_OFF, NULL);

Turns the LCM backlight off.

KeyPad

The device node is /dev/keypad. The key value is defined in moxadevice.h.

int ioctl(fd, IOCTL_KEYPAD_HAS_PRESS, int *flag);

Checks how many keys have been pressed. Argument 3 returns the number of pressed keys. 0 means no keys

were pressed.

int ioctl(fd, IOCTL_KEYPAD_GET_KEY, int *key);

Gets the value of the last key that was pressed. This functions only reads one key value for each function call.

The value of the key value is returned in argument 3.

Special Note

1. The DA-662A series‘ kernel will store the ―pressed key history‖ in a buffer. The maximum buffer size is 31

keys. If the buffer overflows, the first key of the 31 that was pressed will be dropped, without sounding the

buzzer.

2. Currently, the DA-662A series does NOT support pressing more than 1 key at the same time.

Product S/N

The DA-662A series stores the product serial number in the system. You can use the following method to get

Product S/N and utilize the number to develop security functions such as program protection and program

initialization identification. The following example shows how to retrieve the product S/N.

Example:

root@Moxa:~# cat /proc/driver/serid

TABC0123456789

Make File Example

The following Makefile file sample code is provided for reference.

CC = arm-none-linux-gnueabi-gcc

CPP = arm-none-linux-gnueabi-gcc

SOURCES = hello.c

OBJS = $(SOURCES:.c=.o)

all: hello

hello: $(OBJS)

$(CC) -o $@ $^ $(LDFLAGS) $(LIBS)

clean:

rm -f $(OBJS) hello core *.gdb