One MCU two serial I/O

How can I do both wireless serial I/O between an MCU and a PC and also have the MCU do serial I/O with another device? Do I have to find an MCU with two TTL TX and RX lines or is there an alternative? If the I/O does not have to be concurrent can I switch the TX/RX lines between the two devices? I am considering Bluetooth serial I/O between a PC and an Arduino board but I also want the Arduino to communicate with 1-wire devices.

some MCUs (most now-a-days) have two serial port UARTs in hardware, for chips in the $5 area like the newer Atmel AVRs.

Otherwise, you can use a software driven serial port at lower speeds for one of the ports. There are many such examples in products like Zbasic.net and donated software on avrfreaks.net.

No doubt, the same exist for PICs and others.

Both techniques may be used. I use a second software UART.

Leon

Thanks. The software UART is just what I need.