I have 2 devices connected to my ATMega328 USART pins. One is PL2303 USB to TTL converter and the other is Bluetooth <-> USART adaptor.
I was advised that I should not have 2 devices connected at the same time to the USART pins on my AVR as data corruption may occur if both devices are active at the same time and try to drive the AVR RX pin.
The solution I was suggested was to have diodes on the TX line of each of the devices along with a pull up resistor on the AVR RX line. Something like this ..
Can someone explain how this would work?