Radxa Zero UART Pulldown

#1

I am struggling to get UART working on the Radxa Zero. It seems that the RX pin has a pull-down resistor on it as the voltage is 0. Is there any way to swap this pin so that the RX pin has a pull-up resistor? I am trying to use an open drain system.

1 Like
#2

Did you get to the bottom of this? I was trying to do some similar with overlays:

/dts-v1/;
/plugin/;


    / {
    compatible = "radxa,zero", "amlogic,g12a";
    fragment@0 {
        target = <&uart_ao_a_pins>;
        __overlay__ {
            mux {
                groups = "uart_ao_a_tx",
                         "uart_ao_a_rx";
                function = "uart_ao_a";
		/delete-property/ bias-disable;
                bias-pull-down;
              };
            };
        };
    };