Open Source Hardware, Makers and STEM tutorials

ULN2803: all about the Darlington transistor pair

ULN2803

If you are working with transistors, there is probably a combination of these semiconductor devices that will interest you. This is the pair of transistors known as Darlington. This configuration is quite interesting for many DIY electronic projects, and you can find them cheaply in the IC ULN2803.

You will be able to find the ULN2803 manufactured by different companies, like the mythical Texas Instruments, or the European STMicroelectronics, etc. And in this guide article, I will try to solve all the doubts about this product, tell you where you can buy it, and how to work with it…

GPIO: all about Raspberry Pi 4 and 3 connections

Raspberry Pi 4 GPIO

The GPIO pins of the Raspberry Pi 4 board, the 3, and also of its predecessors, give the SBC board similar capabilities to those that Arduino can have, since with them you can create very interesting electronic projects controlled from the operating system through code in different languages, such as Python.

That makes the board more than just a cheap computer. It will allow you to connect a lot of electronic elements that you can use with Arduino, but that can also be controlled from the Pi. In this guide I will try to give you as much information as possible about these GPIO pins so that you can start taking advantage of them…

IMAX B6: the balancing charger you’ll want to have

IMAX B6

One of the most practical gadgets I’ve tried is the IMAX B6 multi-function charger. A product that can serve you to feed many projects with Raspberry Pi, Arduino, since it allows you to charge different types of batteries that are used in projects of many makers.

All these DIY projects need power, and it’s not always possible to leave the Arduino board connected to the PC’s USB for power or you may need a special type of ‘string’ power supply. It is also sometimes not possible to have a specific type of charger for each battery. With the IMAX B6 charger you can get what you need from everything it has to offer.

HC-SR501: Arduino compatible IR motion sensor

HC-SR501

If you want to equip your Arduino DIY projects with the ability to detect proximity or motion, and based on that do some kind of action, such as recording an event, turn on a light, set off an alarm, activate a DC motor, etc, then you should know the HC-SR501 sensor.

This sensor uses IR, like other similar types of sensors, and in this guide I will try to explain everything you need to know to start using it from scratch. From its features, to how to integrate HC-SR501 with your Arduino UNO board, to how to integrate it with . Everything in a more practical way to make it as simple as possible.

Arduino Mega: all about the big development board

Arduino Mega

If the Arduino UNO Rev3 board is too small for you and you want to create more advanced projects and enjoy more power, then what you are looking for is an Arduino Mega board, another of the available models created by the same developers as the original board, but with a faster microcontroller, more memory, and more pins for programming.

Arduino Mega has many similarities with Arduino UNO, but there are some differences that make it very special for all the makers who are looking for something more. Usually, if you are starting out it is not the best choice, but it is if you have already exploited the capabilities of UNO and want to go further.

Joystick Arcade: the best game controllers for your retro projects

joystick arcade

There are a lot of arcade joystick controllers for video games on the market, some of them for DIY arcade machines, such as those compatible with boards like the Raspberry Pi or with Arduino. They don’t have a high price, so they turn out to be a very interesting device to manage your projects and enjoy them like a child.

Choosing the best of these arcade joysticks is no easy task, as there are many of them, and sometimes the differences between them are conspicuous by their absence. But there are some whose small details can make the difference. If you are interested, you can read on to find out what these controllers are, and how to choose the best ones.

The best emulators for Raspberry Pi

There are a lot of fans of retro or classic games. Gamers who have lived in the golden age of the mythical game consoles like Atari, or arcade bartop games from arcades and bars, or have handled historical computers like Commodore64, Spectrum, etc., will surely continue to have the worm of using emulators to be …

Low Pass Filter: all you need to know about this circuit

low pass filter, circuit

The coils and the operational amplifiers allow to create very interesting circuits, such as the famous frequency filters. These filters have many applications in the electronics industry. As is the case with the low pass filter, the high pass filter, etc. They are specially interesting for certain sound applications, being able to filter noise, or more or less low sounds according to their frequency. Therefore, they are very useful.

If you want to know more about the low pass filter, and other filters, and how they can help you in your projects with Arduino or DIY, I encourage you to read on…

Arduino UNO: Free hardware board analysis in depth

Arduino bus I2C

Since the release of ‘Strong’, the Arduino UNO board, much has evolved with the release of its latest revisions. In addition, its creators have been quick to create other similar boards in different formats to cover more needs than the UNO initially covered. Many others have even dared to create their own clone or compatible boards, although not with the same success.

Before the appearance of Arduino there were other similar projects, like the famous Parallax boards with Microchip PIC microcontrollers that could be programmed very easily using languages like PBASIC and others. An example of this is the Parallax Basic Stamp 2. But the fact that it is not free hardware meant that it did not have the same market roots as the Arduino project has had. The Italian board has been a real revolution in this sense.

RGB LED: everything you need to know about this component

LED RGB

There are many types of semiconductor diodes on the market, and within them there is a particular type such as LEDs (Light-Emitting Diode). These types can emit light, but not all of them are identical. Manufacturers play with different compositions of the semiconductor material so that they emit lights of different colours. In addition, there is the RGB LED, which uses various combinations of LEDs to emit light in different colors.

Therefore, if you want to create a project in which a single color LED is not enough, with RGB LEDs you can achieve wonderful multicolor light effects. And they are not very different from conventional LEDs, so you can integrate them with your Arduino board or other electronic projects in a very simple way.