LogoLogo
  • Welcome!
  • Mission Statement
  • Contributing Guidelines
    • Embed CADs in Wiki Articles
  • VEX Worlds Livestream Archive
    • VEX U
    • V5RC High School
    • V5RC Middle School
    • VIQRC Middle School
    • VIQRC Elementary School
    • JROTC
  • ⚙️Hardware
    • Design Fundamentals
      • Gear Ratios
      • Internal Forces (Stress)
      • Torque
      • RPM
      • Center of Mass
    • Introduction to VEX Parts
      • Structure
        • C-Channels and Angles
        • Fasteners
        • Retainers
        • Gussets and Brackets
        • Bearings
        • Plate Metal and Flat Bars
      • Motion
        • High Strength Components
        • Gears and Sprockets
        • Traction Wheels
        • Mecanum Wheels
        • Omnidirectional Wheels
        • Flex Wheels
    • Robot Decorations
      • Part Dyeing
      • Metal Coloring
      • License Plate Holders
    • Lifts
      • Double Reverse Four Bar (DR4B or RD4B)
      • Four Bar
      • Scissor Lift
      • Six Bar
      • Other Lifts
      • Best Practices
    • Shooting Mechanisms
      • Catapult
      • Flywheel
      • Linear Puncher
    • Drivetrains
      • Tank Drive
      • Mecanum Drive
      • Holonomic Drive
      • Designing a Drivetrain
      • Best Practices
    • Pivots & Joints
    • Pneumatics
      • Best Practices - Pneumatics
    • Intakes
    • Flip Out Mechanisms
    • Defensive Mechanisms
    • Misc. Building Techniques
    • VexU
      • Common Manufacturing Techniques
        • 3D Printing
        • Laser Cutting
      • Custom Manufactured Parts Library
      • Commercial Off The Shelf Parts Library
  • 👑Team Administration
    • New Team Resources
      • Creating The Team
      • Gaining Interest for Robotics Teams
      • Attending Competitions
        • Elimination Bracket
    • Team Dynamics
      • Organization Structure and Longevity
      • Member Allocation and Management
      • How *Not* To Run a Team
    • Team Finances
      • One-Year Team Financial Breakdown
      • Funding Your Teams
    • Hosting Competitions
      • Live Streaming
      • Tournament Manager
        • Competition Electronics
        • Creating a Tournament
        • Tools
          • Field Set Control
          • Connecting Mobile Devices
          • Connecting Raspberry Pis
        • Match Control
          • Inputting Match Scores
          • Inputting Skills Scores
          • Inputting Scores on TM Mobile
        • Displays
        • Alliance Selection
      • Additional Event Partner Resources
    • VexU Organization Management
      • Getting Started in VexU
      • Team / Personnel Management
      • Volunteering At Local Events
  • 📚The Judging Process
    • The Engineering Design Process
      • Test and Refine
    • The Engineering Notebook
      • Segments of the Notebook
      • BLRS2 '23-'24 Engineering Notebook
      • Integrating Inventor Models into Documentation
      • Engineering Notebook Rubric Breakdown
    • The Interview
      • Interview Rubric Breakdown
    • Using Notion for an Engineering Notebook
      • How to Setup a Notebook
      • How to Create Entries
      • How to Export a Notebook
      • Purdue SIGBots Notion Template
        • Game Analysis
        • Identify The Problem
        • Brainstorm Solution
        • Select Best Approach & Plan
        • Build Log
        • Programming Log
        • Testing Solution
        • Tournament Recap
        • Innovative Feature
  • 🖥️VEX CAD
    • CAD Programs
      • Inventor
      • Fusion 360
      • Solidworks
      • OnShape
      • Protobot
    • Making a Chassis
      • Inventor Chassis: The Basics
        • Installation
        • User Interface Overview
        • Dark Mode
        • Assemblies
        • Placing Parts
        • Navigating CAD
        • Changing Visual Style
        • Grounding
        • Connecting Two C-Channels
        • Modifying Existing Constraints
        • Toggling Visibility on Existing Parts
        • Completing Half of the Chassis
          • Inner Drive Channel
          • Bearing Flats
          • Motors
          • Wheels
          • Sprockets
          • Spacers, Washers and Standoffs
          • Spacers Cont.
        • Creating Mid-Plane
        • Mirroring
      • Inventor Chassis: Best Practices
        • File Structure
        • Subassemblies
        • Wheel Subassembly
        • Origin Planes
        • Cross Brace
        • Drive Channels
        • Simple Motor iMates
        • Replacing Simple Electronics
        • Completing Half of the Drive
          • Bearing Flats (Best Practice)
          • Wheels
          • Powered Gear
          • Spacer Boxing
          • Spacers, Washers and Standoffs (Best Practice)
        • Model Browser Folders
        • Mirroring (Best Practice)
        • Model Browser Folder (Right)
        • Main Assembly
      • Fusion 360 Chassis
      • Solidworks Chassis, Chain, and Custom Plastic
    • Remembering The Best
      • 62A Skyrise
      • 400X Nothing But Net
      • 2587Z Nothing But Net
      • 365X Starstruck
      • 62A In The Zone
      • 202Z In The Zone
      • 5225A In The Zone
      • 169A Turning Point
      • 929U Turning Point
      • 7K Tower Takeover
      • 5225A Tower Takeover
      • 62A Change Up
    • Scuff Controller
  • 💻Software
    • Odometry
    • Path Planning
    • Robotics Basics
      • Arcade Drive
      • Tank Drive
      • Joystick Deadzones
      • Curvature (Cheesy) Drive
      • Subsystem Toggling
    • Organizing Code
      • Code Style
      • Code Styling Guide
      • Writing Good Comments
      • Version Control
    • Control Algorithms
      • Bang Bang
      • PID Controller
      • Basic Pure Pursuit
      • Flywheel Velocity Control
      • Kalman Filter
      • Take Back Half (TBH) Controller
      • RAMSETE Controller
    • Competition Specific
      • Operator Control
      • Autonomous Control
    • C++ Basics for VEX Robotics
      • Basic Control Flow
      • Enumerations
      • Namespaces (::)
      • Multiple Files (C/C++)
    • VEX Programming Software
      • PROS
        • OkapiLib
      • vexide
      • Robot Mesh Studio (RMS)
      • EasyC
      • RobotC
      • VEXcode
      • Midnight C
    • General
      • Stall Detection
      • Register Programming
      • Sensors and Odometry in Autonomous
      • Embedded Programming Tips
      • Debugging
      • Bit Shift
      • Bit Mask
      • Autoformatting
      • Finite State Machine
      • Data Logging
    • Object Recognition
      • Red Green Buoy
      • AMS
      • OpenCV
      • OpenNI
    • 🤖AI in VRC: Pac-Man Pete
  • ⚡VEX Electronics
    • V5 ESD Protection Board
    • VEX Electronics
      • VEX V5 Brain
        • V5 Electronics Observations and Issues
      • VEX Controller
      • VEXnet and V5 Robot Radio
      • VEX Battery
      • VEX Motors
    • VEX Sensors
      • 3-Pin / ADI Sensors
        • Encoder
        • Potentiometer
        • Limit Switch
        • Bumper Switch
        • Accelerometer
        • Gyroscope
        • Ultrasonic
        • Line Tracker
        • LED Indicator
      • Smart Port Sensors
        • GPS Sensor
        • Rotation Sensor
        • Vision Sensor
        • Optical Sensor
        • Distance Sensor
        • Inertial Sensor (IMU)
        • 3-Wire Expander
    • V5 Brain Wiring Guide
    • Legacy
      • VEX Cortex
      • Power Expander
      • VEX Motor Controller
      • VEX Cortex Wiring Guide
  • General Electronics
    • General Topics
      • External Boards
        • ASUS Tinker Board S
        • Arduino
        • Beagleboard
        • Leaflabs Maple
        • LattePanda
        • Meadow F7 Micro
        • Netduino
        • ODROID-XU4
        • Pandaboard
        • Raspberry Pi
      • Analog-Digital Converter (ADC)
      • Bit-Bang
      • GPIO
      • I2C
      • Jitter
      • Line Noise
      • List of Tools
      • Output Drive
      • Power Consumption
      • Radius Array
      • Resettable Fuse (PTC)
      • SPI
      • Slew Rate
      • Stalling
      • USART
      • UART
      • 5 Volt Tolerant
      • DC Motor Basics
Powered by GitBook
LogoLogo

This work is licensed under a Attribution-ShareAlike 2.0 Generic License

On this page
  • Usage as an input
  • Usage as an output
  • Teams Contributed to this Article:

Was this helpful?

Edit on GitHub
Export as PDF
  1. General Electronics
  2. General Topics

GPIO

A general purpose I/O pin, or GPIO pin for short, is a pin on a microcontroller (ref) which can be used for software-controlled input or output.

PreviousBit-BangNextI2C

Last updated 4 years ago

Was this helpful?

The GPIO port bank on a PandaBoard

GPIO pins are often shared with other peripherals, such as and pins.

Usage as an input

If the internal output driver is placed in a high impedance state, then whatever is connected to the pin will determine its current value. Voltages near the I/O voltage will cause a logic "1", and voltages near 0 V will cause a logic "0". Voltages in between may or may not produce a consistent value, as governed by the logic family of the input device. The high or low value can be read in software, using a function like digitalRead().

Usage as an output

Each GPIO pin also features an output driver, which can set the pin to either a high or low value in software using a function like digitalWrite(). A logic "1" is represented by a voltage close to the I/O voltage of the microcontroller, while a logic "0" is near 0 V.

Teams Contributed to this Article:

Some GPIO pins can handle voltages higher than the I/O voltage. For more information, see .

Unused input pins may cause increased if the input voltage floats about halfway in between the low and high states, along with spurious value changes. To avoid erratic behavior, set the pin to an output mode or use a pull-up resistor.

The actual values of these voltages may vary depending on what type of load is connected to the microcontroller. Pins with high are affected less by the power draw of the connected device. For this reason, devices driven directly by GPIOs should have short wires and low power requirements.

(Purdue SIGBots)

voltage tolerance
power consumption
drive strength
BLRS
UART
SPI