Hi,
Can I check how to set the UART TX pin for LPC5536 as High Impedance? Disabling the interrupt is not sufficient, may need to set as High impedance.
Do I need to set as Input and open drain with no pull resistor?
Is this setting correct?
Why not configure this pin using Config Tools (i.e., Pins Tool). The tool will generate matching source code which you can use directly or compare to the code you came up with.