Hello! Is there any way to get an UART with CTS and RTS in UDOO Quad in the i.MX6 side? Thanks all! good work!
This is probably too late to help the OP, but in case others are wondering ... the only UART with both RTS and CTS mux-candidate pins routed to a connector appears to be UART5, which can put these signals on CSI0_DAT18 and CSI0_DAT19, which go to pins 11 and 15 (CAM_EN & CAM_RST) of CN11, the CSI camera connector near audio jacks,. You'd need the special flat ribbon to mate with this, and unfortunately the TX/RX data pins can't be made to appear on the same connector. Those would have to be picked up from one of two places in the Arduino headers. See discussion of mux registers IOMUXC_SW_MUX_CTL_PAD_CSI0_DATA18, IOMUXC_SW_MUX_CTL_PAD_CSI0_DATA19, and IOMUXC_UART5_UART_RTS_B_SELECT_INPUT in the IMX6DQRM.pdf reference, along with UDOO_REV_D_schematics.pdf for the trace routing. Each has a 4.7kohm pull-up resistor to +3.3V, but that shouldn't normally matter.