SparkFun Forums

[johnty]

assuming the following:

1.) i would like to send data to an arduino board (one hw serial port) from two devices - one of them is the built in usb->serial converter, while the other is an RFID reader
2.) the devices don't talk very often, and they never do it at the same time
3.) i cannot use the software serial library, due to the limitations

from the above, is it possible to drive one serial input with two outputs? (or is this just a bad idea and i should look at getting a board with more ports?)

thanks in advance,

[johnty]

i may have semi-answered my question:

it appears as if there are better software serial libraries out there, such as:

http://arduiniana.org/libraries/NewSoftSerial/

will try it out and see what happens

[johnty]

actually, not quite: seems like the newsoftwareserial library still doesn't appear to be adequate. the rfid code doesn't get read properly (whereas on the actual hw port it does)

[liudr]

As far as I know, the NewSoftSerial is an interrupt-driven serial library. I've used it on my GPS with no problem. Maybe your baud rate is too high?

If you're still trying to use one line for two devices, can't you just get a digital multiplexer? Or maybe an OR gate so that the two inputs can each use the line just fine. Have you used a gate chip, like 7400?