The Raspberry Pi Pico RP2040 chip supports up to 30 digital I/O pins, however not all boards provide access to all pins.
The Raspberry Pi Pico has 3 Input modes settings for use with pinMode: INPUT, INPUT_PULLUP and INPUT_PULLDOWN
Output Modes (Pad Strength)
The Raspberry Pi Pico has the ability to set the current that a pin (actually the pad associated with it) is capable of supplying. The current can be set to values of 2mA, 4mA, 8mA and 12mA. By default, on a reset, the setting is 4mA. A pinMode(x, OUTPUT), where x is the pin number, is also the default setting. 4 settings have been added for use with pinMode: OUTPUT_2MA, OUTPUT_4MA, which has the same behavior as OUTPUT, OUTPUT_8MA and OUTPUT_12MA.
Simple square wave tone generation is possible for up to 8 channels using
tone calls. Because these use the PIO to generate the
waveform, they must share resources with other calls such as