I understand synchronous serial communication conceptually but I'm having trouble with how asynchronous works. Specifically in this situation:
Let's say I want to send a byte: 0x03. We have a start and stop bit, which are low and high, respectively. How does the receiving device "know" that I'm sending a start bit followed by 6 0s? How does it know that that isn't just one long start bit?
Followup: what exactly is a UART? I'm asking what the common use is, as I've seen various places refer to it as a standard and others as a piece of hardware.