P6 is the DAC/ADC line, in addition to a timer. But doesn’t it have to be configured for DAC/ADC first? If I just assign it as a GPIO, shouldn’t it act like a GPIO? I ask because that’s not what I observe. If I set it to a pull-down, it remains up, but if I set it to a pull-up, I can pull it down with a switch. So it doesn’t “respond correctly” to a switch, the way, say, P4 and P5 do, which both respond to a switch correctly in both pull-up or pull-down fashion.
I just hooked a momentary switch between pins 4, 5, or 6 and the 3.3V rail for a pull-down/switch-up test and the ground rail for a pull-up/switch-down test…which I presume was the proper arrangement.
Is there any overarching electronic philosophy as to whether it is better to configure switches in a pull-up/switch-down fashion or the other way around?