Ricardo - thanks for your input. To confirm, UART1==ttymxc0, UART2==ttymxc1 and finally UART3==mxc2. With Eric's assistance we have been able to perform test communication via UART1 - (console port) need to use UART2 for actual data transfer - on the EVK adapter board MCIMX51EXP) due to console use of UART1. I see UART2 routed to a secondary DB9 connector (MCIMX51EXP). Cannot get any activity on this UART into/out of the EVK. Communication code in Java within Android OS - (byte-array) transfers initiated by fixed interval timer. Appreciate any serial I/O code you're willing to share.