I would like to connect 4 UART output sensors to one serial port of my controller. The distance between sensors and controller will be about 10m. Initially I was thinking of using 485 as physical layer (SP3485 tranceivers). Sensor UART --> SP3485 -- (485 layer) -- SP3485 --> UART Controller.
A seperate current controlled cirquit will do the sesnor select job enabling the transmit output for each sensor (DE/RE' pins SP3485)
2,5mA - Enable transmit from sensor 1
7,5mA - Enable transmit from sensor 2
12,5mA - Enable transmit from sensor 3
17,5mA - Enable transmit from sensor 4
Is there any other ideas or suggestions?