USB

All DUELink modules include USB support. A few boards have a built-in USB connector, but others need an adapter like USB Hook or USB Stick.

USB on DUELink module is configured in standard CDC class, making these modules show up as virtual serial port to the connected Hardware.

No drivers are necessary on any modern Windows, Linux, Android or Mac operating systems. These systems use a Host Language to command a Daisylink of modules.

USB is also first choice with the Console and Demo Website.

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HID Interface

The USB connection presents itself as CDC (Virtual Serial) Class, but it also includes HID (Human Interface Device) Class. A connected computer/phone will see Serial+Keyboard+Mouse devices on the same USB cable (composite device), no matter what OS is being used.

The virtual serial interface is used to communicate with the engine. This works just like all other interfaces.

Through the HID interface, a connected OS will receive "keyboard keystrokes" and "mouse movements, thanks to the Hid(type, [data]) function. type is 1: Keyboard - 2: mouse. The [data] array depends on the device type.

Type Mouse:

Data	Use
Byte 0	Buttons (bitmask: Left=1, Right=2, Middle=4)
Byte 1-2	X movement (signed int16)
Byte 3-4	Y movement (signed int16)
Byte 5	Wheel (signed int8)
Byte 6	Pan (signed int8)

Type Keyboard:

Data	Use
Byte 0	Modifier keys (e.g., Ctrl, Shift)
Byte 1	Reserved (always 0)
Bytes 2-7	Keycodes for up to 6 simultaneous key presses

Modifier key	Value
Left Ctrl	0x01
Left Shift	0x02
Left Alt	0x04
Left GUI	0x08
Right Ctrl	0x10
Right Shift	0x20
Right Alt	0x40
Right GUI	0x80

USB Keyboard keycodes are found in the USB Specifications https://usb.org/sites/default/files/hut1_21.pdf and in many other places online, like https://gist.github.com/MightyPork/6da26e382a7ad91b5496ee55fdc73db2.

For example, the codes for 'G', 'H' and 'I' are 0x0A, 0x0B, and 0x0C respectively.

This is an example that reads touch pads on a DUELink module and then send their status as keyboard arrows key presses.

Asio(1) # Enable Asynchronous Commands
dim b1[8] # keyboard need 8 bytes for one report
 
_p = 0 # press status
_s = 0 # backup status
 
while (1)
    if (TouchUp())
        b1[2] = 0x52
        _p = 1
    end
    if (TouchDown())
        b1[2] = 0x51
        _p = 1
    end
    if (TouchLeft())
        b1[2] = 0x50
        _p = 1
    end
    if (TouchRight())
        b1[2] = 0x4F
        _p = 1
    end
    if _p != _s
        if _p = 1
            hid(1,b1) # send key        
        else
            hid(1,[0,0,0,0,0,0,0,0]) # release    
        end
        _s = _p
    end
    _p = 0 # reset press status
wend

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Linux Support

USB presents itself as a virtual USB-Serial port. Linux requires permissions to allow access to these ports. Further notes and example script are on the UART interface page.