Category Archives: Integrated Circuit

Using a Real-Time Clock (RTC) – NXP PCF8563P – with an Arduino

In this post, I will explain what a Real-Time Clock (RTC) is about and how to use it in your circuits. I will be using the NXP PCF8563P chip for the examples. You can find the data sheet for that chip here. A RTC is used to keep track of date & time in your circuit and make it available… Read more »

Police Car Strobe Lights using a 555 Timer and a 4017 Decade Counter

Introduction Today, we will solve the mystery behind police cars strobe lights! Seriously, I was looking at a way to simulate those lights using simple LEDs and without any rotating components. Here’s the result on a breadboard: Solution The solution to that problem was pretty simple. I used a 555 timer to trigger a 4017 decade counter. I used 4… Read more »

Adding pins to your Arduino using I2C and a PCF8574P chip

You are working on a project built around an Arduino and you realize you won’t have enough I/O pins to do everything? There are different ways of working around that limitation. One of them is to use an Inter-Integrated Circuit (I2C) bus and a PCF8574P chip. That chip will provide you with an additional 8 I/O pins at the cost… Read more »

IoT Object : ESP8266 + DHT-11 on

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There’s a lot of buzz around the Internet of Things (IoT) these days. This post explains how to create your own IoT object that will read your house air temperature and humidity and send that information to a web site called Once your data is on ThingSpeak, you’ll be able to visualize it to see how the your house… Read more »

Introducing the 4017 Decade Counter

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The 4017 decade counter is a chip typically used for 10 of its output pins. It turns them on, only one at the time, in a sequence from 0 to 9. The chip waits for an external signal to switch to the next pin. Pinout Power Pins: – Pin #16 (VCC): Connect to VCC – Pin #8 (GND): Connect to… Read more »

Using 555 Timer/Oscillator

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The NE555 timer is one of the most popular Integrated Circuit (IC) out there.  It is sold since 1971, so it’s not exactly a new IC but it still does his job very well!  Even today, over a billion units are produced every year! The 555 timer is an integrated circuit that can be used to produce different kinds of… Read more »