Did you run out of input pins, don't worry here is a solution without any shift registers.

A quick and compact Arduino Nano setup with four DIP switches to allow for mode selection. Power is provided by CR2032 battery package.

Probably the most useful Arduino project I've ever made! A automatic tester for a product I sell.

A bit more accurate than __TIME__.

Use the IO Expander and Relay Expander with the Arduino to control up to 65,280 relays!

Improved version of the soldering iron controller for Hakko 907 iron. To simplify building the controller, LCD screen is implemented.

Need fast cheap laser rangefinder for your Arduino project? You can use a laser tape measure for this!

The soldering iron controller based on arduino that implements PID method to keep the temperature of the iron.

The software library to calculate moon age, sunrise and sunset time.

Step by step approach is followed so that any hobbyist or design engineer can have a better understanding of the basic concepts.

FreeRTOS, simple, easy, robust, and optimised for Arduino IDE. Using FreeRTOS Semaphores to share and protect physical resources.

The Companion IC is a very cool looking Clock + Ohmmeter + Capacitance Meter + Diode Tester!

How to make projects more robust and reliable using drivers ULN2803, UDN2981 and PNP transistors.

A programmable, portable, rechargeable power supply based on Arduino featuring an OLED display for viewing V.I.P. of projects/prototypes.

On this simple tutorial, we will explore how to discover colors using an Arduino and the TCS 3200 sensor, displaying it on an LCD.

Measure rotation speed (RPM) with Optocoupler and Encoder disk and Arduino - Quick and Easy!

In this project, you can measure typically up to 48V. It is recommended to use Arduino digital voltmeter as “0-48V DVM”.

Control your Commodore C-64, reset C64, select Kernal, BASIC and Charset ROM, SD2IEC device#, info display.

Build a treasure chest or use an existing storage box, attach a push-button quadrature rotary encoder (endless spinning dial) and lets go!

Connect Matrix Keyboard using only 2 Arduino pins by using PCF8574/PCF8574A I2C GPIO - Quick and Easy!

A homemade semi-automatic antenna tuner for HF controlled by an Arduino Nano.

In this project, I am going to make a LAN cable tester with just a few basic electronics components. It cost me just a bit over $3.

This project is all about making a power inverter using arduino. The Inverter produces 220VAC from 12V battery.

Get accurate readings for voltage using arduino.