What is the resistance in Raspberry Pi 5 GPIO pin?
The resistance of a Raspberry Pi 5 GPIO (General Purpose Input/Output) pin isn't a single fixed value; it depends on whether the pin is acting as an input or an output , and the state it's in. Here’s a breakdown of the different scenarios: 1. As a Digital INPUT Pin When you configure a GPIO pin as an input (e.g., to read a button press), its key characteristic is very high input impedance . Effective Resistance: Typically >1 MΩ (over 1,000,000 Ohms). Why? A high-impedance input requires almost no current to read the voltage level. This is ideal for sensing because it doesn't disturb the circuit you are measuring. It's like listening very carefully without talking. Practical Implication: You must use an external pull-up or pull-down resistor (either physical or internal) to define the pin's state when it's not being actively driven (e.g., when a button is not pressed). The internal pull-up/pull-down resistors are typica...