Wouldn't it just be faster to toggle the bits at the registry level? Moreover, this library uses digitalWrite to transmit the bits.

So the only way this could be happening is if there was some sort of multi-threading correct? Because by setting vw_tx_enabled to true, the transmission process would begin inside vw_Int_Handler. But this function is never called in vw_send() or vw_tx_start(). However, the actual transmission of the message happens inside vw_Int_Handler(). So there is no where in this flow where the message is actually being sent. Then this function returns, followed by the immediate return of vw_send().

Inside that function, it enables the transmitter hardware and sets the variable 'vw_tx_enabled' equal to true.Then before the function returns, it calls vw_tx_start().Inside this method, it will start to encode the message and create the packet.In the Arduino IDE, call vw_send() with the right parameters.

After looking at the code, the process I gathered is the following. I am a little confused on how exactly VirtualWire's 'send' function works.

Virtual wire library arduino