I want to receive data on the RX1 pin on the UNO while monitoring other activities on the USB connection. assuming that bps, handshake, etc are same for both RX1 and the USB connection. Can this work?
Not on an UNO, since those pins are used for USB communication. You can do that on a leonardo since the USB communications do not use the AVR's UART
Thanks much. I was afraid of that. I do assume, thought that i can load sketches via the USB that use the tx1/rx1 port with the USB disconnected and that I will be able to write over those sketches with the USB port so long as tx1/rx1 are inactive - all this on the UNO, of course.
I just fried my mega2560 through no fault of its, and I was pondering whether i could move my application back to the UNO, but i need one hardware serial port in order to run Gammon's 9 bit hardwareserial lib. the mega made this easy.
You could use an intermediate processor, the ATMega1284. 2 hardware serial ports, 128K flash, 16K SRAM. DIP also for ease in breadboarding - or replacement for when it fails through no fault of its own. I've got a bare board that looks like a Duemilanove for '1284 with the extra IO broken out, populate it with headers, etc. to suit your needs. Details are at my signature link. Works greate with maniacbug's IDE core files.