One serial port, One Xbee and One optional external device!

[tomshirvo]

Hi All,

Sorry I really didn't know how to subject this one.

I am using an Arduino Due for my project, it will be placed in a waterproof enclosure with a few connectors coming out of it. All of the (standard/normal) communication is over Xbee ZB using API mode 2.

One connector will have power but I also want to bring out the RX and TX lines of the Arduino (same pins the Xbee uses) so I can communicate with it directly. The plan was to be able to unplug the cord that powers the device, then plug in this other device which will power it and also connect to these RX and TX lines.

My ideas were that if I was to replicate the Xbee framing system through this connected device it would still work. So sending data would be fine from this external device would work in a code side of things as the Arduino would think it is direct from the Xbee. The receiving is another problem but I think I can get around that by having the external device send a command to make the frame checksum incorrect so the Xbee just ignore it.

So this should work in the code side of things but what about the serial electrical side of things??

Will having the Xbee still connected stuff with the RX/TX from the external device. If this is the case is there anyway around this???

The other way I was thinking was to get a connector with more pins and use transistors on the Xbee side to disconnect the line but I was hoping to not have to do that.

I hope this can make sense to whoever reads it. My brain has it's own language that only I seem to understand.