Trace: • usb_addlistener()

expr:functions:func-usb_addlistener

usb_addlistener()

Adds USB listener, which reads data from USB device and saves it in array. Each time device sends new data, array data is refreshed and callback function is executed.

Syntax

usb_addlistener(path, callback, hnd, size);

Parameters

path	USB device path.
callback	Callback function name. Callback function arguments are:
	arg1 - path
	arg2 - array handle
	arg3 - length
hnd	Array handle.
size	Number of bytes to read. Special values are:
	0 - USB packet size.
	-1 - USB packets are read without interruption, data is read until buffer is full.
Return Value	Number listeners.

Examples

hnd = array_new();
usb = "\\?\hid#vid_045e&pid_028e&ig_00#8&3b73941c&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}";
usb_addlistener(usb, "#On_USB_Event", hnd, 14); 
 
#On_USB_Event
result = array_getdata(.arg2,11);

result:

See also

usb_remlistener, array_new, array_getdata

expr/functions/func-usb_addlistener.txt · Last modified: 2023/02/15 15:01 by 127.0.0.1