Can you communicate to a specific usb port without a usb device, then later use FSK?

[skatefast08]

Can you communicate to a specific usb port without a usb device? If so, I want to send a signal that I can transmit via RF to another device using FSK (Frequency Shift Keying). I can design the RF circuit, but have little knowledge about USB devices and how they work, but if I can communicate to a USB port using Visual studios (C++ knowledge), then I might be able to implement something.

 

[KlausST]

Hi,

There are a lot of documents telling how USB works. From simple explanations ... up to very detailed.
Do a search and read through them.

It makes no sense to me ... at least I don't understand...please add a sketch.

Generally:
USB communication is "initiated" by the USB_device by pulling one of the USB_data lines HIGH/LOW (don't know exactly).
Which line (which level?) ... determines the device's USB standard (speed).
This means: the USB_master / the USB_hub can not know which speed to use before the USB_device is connected.

But besides this .... what/how do you want to communicate with a partner that does not exist?

Klaus