phkaccess
29th March 2005, 05:27 PM
Is there an USB adept out there who would know if this is technically and programmatically possible:
A loopback connection via USB with an external Switch. USB+ and USB- are bridged via an external switch or button. Every 20ms or so, a packet is being sent to the device itself. If the switch is closed, the packet can be received, which fires an event (probably an error because of bouncing), but an event that can nonetheless be handled as an user input.
_________ usb+
| -------------
device | \ button/switch
USB | -------------
--------- usb-
Any idea?
Are there libraries available for eVC++ that expose the USB port as a virtual COM port?
Reason for asking: with external switches and an accessibility software, the devices become accessible for handicapped users. Up until now, legacy RS232 hardware handshake could be used to generate an user input, but these interfaces tend to become extinct with the newer devices.
Thanks for any hint
Phil
A loopback connection via USB with an external Switch. USB+ and USB- are bridged via an external switch or button. Every 20ms or so, a packet is being sent to the device itself. If the switch is closed, the packet can be received, which fires an event (probably an error because of bouncing), but an event that can nonetheless be handled as an user input.
_________ usb+
| -------------
device | \ button/switch
USB | -------------
--------- usb-
Any idea?
Are there libraries available for eVC++ that expose the USB port as a virtual COM port?
Reason for asking: with external switches and an accessibility software, the devices become accessible for handicapped users. Up until now, legacy RS232 hardware handshake could be used to generate an user input, but these interfaces tend to become extinct with the newer devices.
Thanks for any hint
Phil