Do you ever need to drive something with more power than your microcontroller pin can handle? That is where MOSFETs come in. They are digital switches that can handle much more current than a GPIO pin.
Controlling a Solenoid
Many products use solenoids to open and close valves. A microcontroller can control solenoids programmatically using a GPIO pin and a simple circuit.
Using Pull-Up and Pull-Down Resistors
An embedded microcontroller utilizes input/output (IO) signals to communicate with the outside world. The simplest form of IO is commonly referred to as general purpose input/output (GPIO) where the GPIO voltage level can be high, low, or high-impedance. Pulling resistors are used to ensure GPIO is always in a valid state.
Understanding Microcontroller Pin Input/Output Modes
General purpose input/output (GPIO) pins on microcontrollers have various modes for both input and output. Input modes may include pull-up or pull-down resistors, hysteresis, or some combination. Output modes can be push-pull, high-drive or open-drain.