November 17, 2017
What "5V tolerant" means is that there are clamping diodes to 3.3 volts (or whatever the processor is running on) and the port will not be destroyed by 5 volt inputs. Apparently it is even possible to connect them to an i2c device running on 5 volts and have things work. You need to disable the pullups in this scenario. No telling about the uarts, but it is hopeful. The structure of a port looks like what is in the diagram before (but I don't think this applies to a port in analog input mode).
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