Category Archives: Microcontroller

Using a TCRT5000 sensor with your Arduino

You need to know if an object is close to another one but without using a contact switch? The TCRT5000 sensor is a great and cheap option for that! It essentially consists into 2 parts bundled together: an infrared emitter and a photo-transistor.   Drawing 1: No object close to sensor Drawing 2: An object is close to the sensor,… Read more »

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 »

Reducing your ATtiny85 power consumption

      No Comments on Reducing your ATtiny85 power consumption

In this post, we will look at different techniques to reduce your AVR micro-controller power consumption. This is especially useful if you are running your device from batteries since it will allow them to last longer. More specifically, we will look at the impact of changing the micro-controller speed (frequency) and also at the impact of using sleep modes so… 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

      No Comments on IoT Object : ESP8266 + DHT-11 on

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 »

Programming an ESP-8266 with FTDI Programmer

The ESP-8266 is one of my best findings of 2015. I wanted to experiment a bit with what’s called the Internet of Things (IoT). It obviously involved connecting my projects to the Internet, so I looked for a wifi module that I could use with one of my ATtiny microcontrollers to push data to the Internet. On eBay, I found… Read more »

Programming an ATtiny with an USBtinyISP programmer

What is an ISP programmer about? In one of my previous posts, I explained how to program an ATtiny by using an Arduino Uno as an ISP programmer. Today, I will explain how to use an USBtinyISP programmer instead. An USBtinyISP is used to perform what is called In-System (ISP) Programming. In other words, it is used to upload a… Read more »

Programming an ATtiny using an Arduino Uno

      No Comments on Programming an ATtiny using an Arduino Uno

Progamming an ATtiny micro controller can be done using an Arduino. Step 1: Prepare Arduino IDE Make sure your Arduino IDE is supporting ATtiny micro controllers. Look at this post for more details about how to configure your IDE to do that. Step 2: Prepare your Arduino Uno To use your Arduino Uno as a programmer, prostate you have to… Read more »

Setup Arduino IDE to program Attiny 13/44/45/84/85

      1 Comment on Setup Arduino IDE to program Attiny 13/44/45/84/85

This post explains how to install the popular Arduino IDE (v1.6) on your computer and configure it so you can program Attiny micro controllers. Install Arduino IDE First, download the IDE from this location: Arduino IDE download site. Once it is downloaded, you can run the program. What you downloaded is the application, not an installer, so simply move that… Read more »

Plant Watering Indicator (Part 2)

      1 Comment on Plant Watering Indicator (Part 2)

In part 1 of that post, I showed the PCB design for that project and how I produced it. This design relies on an Attiny13a: You will see that the following code is not done using regular Arduino functions. I used the registers directly instead. The reason for that is that you have only 1KB of space to store the… Read more »