[SOLVED] Asynchronous Communication: 2 wire to 1 wire?

[jsherman]

Hi all,

Sorry if this is a repeated topic post - I'm new, couldn't find anything that answered my question after a quick search, so I figured I'd throw it out there.

I'm designing a side project where I want to grab some GPS info to open/lock a box. The GPS chip I have, though, has a single pin for asynchronous serial communication for both Rx/Tx:
**broken link removed**

The microcontroller I'm trying to interface with is a PIC, and seems to only support a 2 pin asynchronous serial communication protocol:
**broken link removed**

The GPS chip looks like it works by receiving a command word serially and then sending the information back out the same pin. I figure an easy solution is to add a 2:1 bidirectional mux and trigger it using the "Transmitter Empty" interrupt. Timing shouldn't be an issue there as I'm planning to run my clock on the order of low MHz. However, I'm a little unsure about this solution and was hoping you guys could give me some feedback!

Thanks!

 

[betwixt]

It's easier than that, just link the Tx and RX pins of the PIC together and enable the TX and Rx functions as needed. That way the PIC won't respond to it's own output but will be ready to see the reply from the GPS module. No MUX needed!

Brian.