Install Mosquitto on a Raspberry Pi

01-28-2018 Alex 0

In this tutorial we’ll learn how to install Mosquitto on a Raspberry Pi. The goal is to use the Raspberry Pi as a MQTT broker in an IoT application. We’ll install Mosquitto, configure it and test it to make sure everything was correctly set up.

Final power supply board

How to build a dual voltage power supply for your breadboard

01-14-2018 Alex 0

One of the most popular articles on this website is the tutorial on how to build a 5V power supply on a breadboard. Following up on that, today we’re going to build a power supply that can output both 3.3V and 5V at the same time. This is particularly useful for circuits where both voltages are needed. We will solder the components on a small protoboard, which will conveniently plug directly into the power rails of our breadboard.

Enable syntax coloring in Nano on Mac OS X

12-14-2017 Alex 0

The basic version of Nano that comes with Mac OS X doesn’t support syntax coloring, and it’s pretty hard to find clear information online about how to enable it. Here is a quick guide on how to enable syntax coloring in Nano on Mac OS X.

python socket server

Simple socket server in Python

11-15-2017 Alex 0

Sockets are one of the most commonly used communication tools on computers, but they can be hard to understand at first. If you break it down however, it’s easy to understand how to use them. In this tutorial we’re going to learn how to implement a simple socket server in Python, that will accept a single client connection.

python keylogger

Simple keylogger with Pynput in Python

11-05-2017 Alex 0

In this tutorial we will focus on logging keyboard events using the Pynput library in Python. I have a Raspberry Pi that I use without a keyboard or mouse, and that is plugged in to my TV. As I mentioned in this tutorial on xdotool, my end goal is to play old games with RetroPie. The only problem is that it’s impossible to control the games over SSH. One possible solution that I found, is to use my laptop to send keyboard events to the Rasperry Pi’s OS.

raspberry pi keyboard

Simulate keyboard and mouse events with xdotool on a Raspberry Pi

10-14-2017 Alex 0

In some situations, it can be useful to simulate user events on a keyboard or mouse, without an actual keyboard or mouse. The original idea that made me look into this subject, was that I wanted to run RetroPie on my Raspberry Pi with different ways to control the system. Instead of a keyboard, I wanted to use GPIO inputs (buttons or joysticks), or even a web interface that I could access from my phone. We’ll use a program called xdotool to do this.

set up raspberry pi

How to set up a Raspberry Pi without a keyboard, mouse or monitor

09-11-2017 Alex 0

The Raspberry Pi is a small single board computer that was originally intended for education and developing countries. In the last 5 years, it achieved way more than this, as it is now one of the best and easiest platforms for tinkerers and DIYers. It is basically a full Linux computer with a small form factor and energy consumption, making it ideal for homemade projects. Most of the time, you can use the Raspberry Pi as a headless machine, without a monitor, keyboard or mouse, and just use Telnet or SSH to access it. This considerably reduces the total cost of a project, as there will be no need to buy a screen, keyboard or mouse. However, the tricky part of this setup is the first installation of the OS. In this tutorial we’ll learn how to set up a Raspberry Pi in a fully headless way.

static IP

Give a static IP address to your Raspberry Pi

09-03-2017 Alex 0

When working with a Raspberry Pi, it is often convenient to give it a static IP address. For example, if you use it as a DNS server to block ads with Pi-Hole, you don’t want its IP address to change over time. Let’s learn how to give your Raspberry Pi a static IP address!

raspberry pi

How to connect a Raspberry Pi to a Wifi network from the command line

09-03-2017 Alex 0

It is often useful to connect a Raspberry Pi to a Wifi network, and with the latest models, there is no need for a Wifi dongle anymore, as it is integrated into the board. It can however be tricky to set up the Wifi when there is no desktop interface. In this tutorial we’re going to learn how to configure a Raspberry Pi to connect to a Wifi network, with the command line interface.

Interrupt handler

How to handle interrupts on a PIC microcontroller

08-26-2017 Alex 0

Most of the time, embedded systems have time sensitive inputs that need to be handled as soon as they are triggered, with minimal delay. This is usually done by using interrupts. Interrupts are pieces of code that are run when an event occurs on one of the microcontroller’s ports, or internal components such as a timer. The execution of the main program is paused, and the microcontroller jumps to the interrupt code (in reality, it jumps to a given address in the program memory, reserved to the interrupt instructions). Once it  finishes executing the interrupt code, it will go back to where it stopped in the main program. In this tutorial we’re going to learn how to implement an interrupt when a user pushes on a button.

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