Logic Level Basics

Learn what a logic level is, and how to interface between different technologies, with a few of our tutorials!

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Not all boards use the same voltage for logic levels. Before connecting your microcontroller or single board computer to a device, make sure that you understand logic levels with our tutorial!

Logic Levels

June 3, 2013

Learn the difference between 3.3V and 5V devices and logic levels.

Don't forget to check out a few of the examples below using a logic level converter to protect your I/O pins and ensure safe communication between different devices.

Bi-Directional Logic Level Converter Hookup Guide

An overview of the Bi-Directional Logic Level Converter, and some example circuits to show how it works.

Single Supply Logic Level Converter Hookup Guide

The Single Supply Logic Converter allows you to bi-directionally translate signals from a 5V or 3.3V microcontroller without the need for a second power supply! The board provides an output for both 5V and 3.3V to power your sensors. It is equipped with a PTH resistor footprint for the option to adjust the voltage regulator on the low side of the TXB0104 for 2.5V or 1.8V devices.

PCA9306 Logic Level Translator Hookup Guide (v2)

A quick primer to get you going with the PCA9306 Logic Level Converter - a dedicated I2C translator.

You can also add a transistor or relay to control devices operating at higher voltages like the tutorials listed below!

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A crash course in bi-polar junction transistors. Learn how transistors work and in which circuits we use them.

Beefcake Relay Control Hookup Guide

This is a guide for assembling and basic use of the Beefcake Relay Control board

Internet of Things Experiment Guide

The SparkFun ESP8266 Thing Dev Board is a powerful development platform that lets you connect your hardware projects to the Internet. In this guide, we show you how to combine some simple components to remotely log temperature data, send yourself texts and control lights from afar.

Comments 2 comments

  • Member #134773 / about 4 years ago / 2

    It's an excellent tutorial for the beginner, though I have one minor quibble:

    There are several different technologies that have evolved over the past 30 years in electronics to define the various voltage levels.

    TTL first started appearing in the 1960s, and there were others earlier than TTL. If you include the rare vacuum tube logic, you can easily double the "30 years".

    • I'm not sure what the original author was referring to in the Logic Level tutorial with the "past 30 years" but you are correct. We could go even farther back if we include vacuum tube designs. ;)

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