Secondary display API

API Overview

The calling sequence is open>ctrl_devs/write_picture>close

open

void* customer_display_open(int* pError)

Open the CustomerDisplay device. This operation should be used before other operations.

Parameters
pErrorCode	int*： if out is null, can not open, else, the out is the handler

close

int customer_display_close(int nHandle)

Close the CustomerDisplay device opened before. The open and close apis are pair operations. If you don’t want to use this device, you should call the close api to release this device.

Parameters
nHandle	int： Handle of this device, returned from open

Returns
int	The result code, >= 0, success; <0 error code.

ctrl_devs

int customer_display_ctrl_devs(int nHandle, int nCmd, int nValue)

Use the function of the CustomerDisplay, such as set background, display default screen, open or close led, buzzer beep and so on.

Parameters
nHandle	int： Handle of this device, returned from open
nCmd	int： Control command
nValue	int： Value of control command

find nCmd and nValue from the follow table:

nCmd	nValue
0x04:set background.	RED :0x001F;BLACK:0X0000;YELLOW:0X07FF;BLUE:0XF800;GRAY0:0XCE9A.
0x05:display default screen.	0
0x06:led.	1:open led; 0:close led.
0x07:buzzer.	0

Returns
int	The result code, >= 0, success; <0 error code.

write_picture

int customer_display_write_picture_data(int nHandle, unsigned int nXcoordinate, unsigned int nYcoordinate,unsigned int nWidth, unsigned int nHeight ,unsigned char* pData, unsigned int nDataLength)

Write picture point data(one point to 4 bytes in ARGB8888). You need firstly convert a Bitmap to point data.

Parameters
nHandle	int： Handle of this device, returned from open
nXcoordinate	unsigned int： X cordinate
nYcoordinate	unsigned int： Y cordinate
nWidth	unsigned int： width
nHeight	unsigned int： Height
pData	unsigned char*： All point data
nDataLength	unsigned int： Point data length

Returns
int	The result code, >= 0, success; <0 error code.