In this Blog, we are going to see the GPIO, so what is GPIO the name itself it has the meaning general purpose input and output. now you are having any kind of microcontroller, that has GPIO. if your having Arduino, it has 14 digital pins, 6 analog pins, if you are having Raspberry Pi it has 40 GPIO pins (models B+, 2B, 3B, 4B), if your having STM32 it has Varies by model, typically 16 to 64 pins, AVR 8051 it has Typically 32 pins, if your having PIC it has Varies by model, typically 16 to 64 pins
| Microcontroller | GPIO Pins |
|---|---|
| Arduino | 14 digital pins, 6 analog pins1 |
| Raspberry Pi | 40 GPIO pins (models B+, 2B, 3B, 4B)2 |
| STM32 | Varies by model, typically 16 to 64 pins |
| AVR 8051 | Typically 32 pins |
| PIC | Varies by model, typically 16 to 64 pins |
if you want to interface with any external module with your microcontroller you can use the GPIO pin has a host.
If you want blink an LED in the any of the microcontroller, then you can have to control the LED using any of the GPIO pin in that specific microcontroller. Not only internal controller if you want to interface microcontroller with any module. At the time you have to use GPIO to interface with external module
Why GPIO Matters
GPIO pins are crucial for a plethora of applications:
- Input/Output Operations: Reading data from sensors, buttons, or switches (input) or driving LEDs, motors, and other actuators (output).
- Communication: Enabling devices to communicate with each other via protocols like I2C, SPI, or UART.
- Flexibility: GPIO pins can be repurposed across different projects, making them invaluable in prototyping and development.
Practical Tips for Working with GPIO
- Pin Configuration: Always start by configuring your pins correctly—define whether each pin will act as input or output.
- Pull-up/Pull-down Resistors: Use these to ensure your input pins are not left floating (undefined state) when no signal is present.
- Debouncing: When working with mechanical switches, implement debouncing to prevent false triggering from contact bounce.
- Protection: Protect your GPIO pins from high currents or voltages using resistors or diodes to prevent damage to your microcontroller
PIN CONFIGURATION INSIDE GPIO
- Active High(pull up)
- Active Low (pull down)
- Push-Pull
- Open drain
Active High
The microcontroller of the GPIO pin is directly connected with VCC its default active High when you make it low example push button of the gpio is defaultly connected with VCC of the power supply when you press the button it goes down leads to gnd. In between the connected resistor called pull-up resistor for to avoid the damage from power supply of VCC
Active Low
The microcontroller of the GPIO pin is directly connected with gnd its default active Low when you make it High example push button of the gpio is defaultly connected with Gnd. when you press the button it goes down leads to Vcc make it high. In between the connected resistor called pull-down resistor
Push-pull
It has the CMOS circuit, it has PMOS and NMOS,
PMOS if you have given the 0 from the Vin to the PMOS has to be active. output=vdd
NMOS, if you have given the 1 from the Vin to the NMOS has to be Active. output=gnd
Open drain configuration
In open drain configuration there is no PMOS is there only using NMOS, whether the output is become zero or floating pin. Example, the open drain configuration has to be used in I2c protocol. its defaultly High state like floating pin. when you make the pin Low the communication will be started