I have a few questions about what I have observed using UART to communicate between two microcontrollers in the lab a few hours ago.
For those who dont know, UART is a form of serial communication and that is asynchronous.
1.) When the whole thing was powered by a single power supply and data was being transferred from one microcontroller to the other via UART through a single copper wire the data was properly received (indicated by a bunch of LEDs). When I supplied each microcontroller with its own power and ground with the only thing connecting the two was the wire for the UART transmission data was no longer being properly received. Is this something that you would naturally expect to happen? So is there really a rule that a wired communication between the two would only work if they shared the same ground?
2.) I have a half duplex FSK data transceiver operating at 433MHz that can handle UART transmission. If I used this for the data transmission to replace the physical cable, would I then be able to separate the ground and power of the two sides?
3.) According to the website I bought the transceiver from, it has a transmit to receive latency of 20-30 ms. Also it operates at 9600 bps. Naturally I have set my microcontroller's UART peripheral to shift out bits at 9600bps. But what about the 20-30 ms, do I also have to consider it in my code?
For those who dont know, UART is a form of serial communication and that is asynchronous.
1.) When the whole thing was powered by a single power supply and data was being transferred from one microcontroller to the other via UART through a single copper wire the data was properly received (indicated by a bunch of LEDs). When I supplied each microcontroller with its own power and ground with the only thing connecting the two was the wire for the UART transmission data was no longer being properly received. Is this something that you would naturally expect to happen? So is there really a rule that a wired communication between the two would only work if they shared the same ground?
2.) I have a half duplex FSK data transceiver operating at 433MHz that can handle UART transmission. If I used this for the data transmission to replace the physical cable, would I then be able to separate the ground and power of the two sides?
3.) According to the website I bought the transceiver from, it has a transmit to receive latency of 20-30 ms. Also it operates at 9600 bps. Naturally I have set my microcontroller's UART peripheral to shift out bits at 9600bps. But what about the 20-30 ms, do I also have to consider it in my code?