OpenCV is one of the best computer vision tools available out there. It is the most popular machine vision library among developers and makers. Due to being open-source, the library has enjoyed vast community support and evolved as one of the most mature software packages. OpenCV itself stands for “Open-source Computer Vision.” The latest version…
How to play musical notes on Arduino
Adding sound to Arduino is fun, and interfacing speakers with Arduino is relatively straightforward. You can directly attach a speaker to Arduino or connect a speaker through an amplifier circuit. In both cases, Arduino can output digital audio from any GPIO. Whether or not one needs an amplifier circuit depends entirely on the selected speaker.…
How to build a portable WiFi repeater using ESP32 or ESP8266
Typically, a WiFi network has a range that’s above 45 meters. The signals are strongest near the router. The further away you move, the weaker the signal. The same is true of thick walls or additional floors in a home or building. The WiFi signals could be completely lost on other floors of a premise. …
How to make a decorative coconut tree using a digital RGB LED strip
In this project, we’ll demonstrate how to make a colorful, king-sized coconut tree (5 feet) decorative showpiece using a digital RGB LED strip. The RGB LED strip is cut and arranged to form the shape of a coconut tree. The ATMega328 microcontroller is used to control the LED strip, generating several flashing, fading, and blinking…
RGB LED decorative, tabletop coconut tree
In this mini-DIY project, we will make a color-flashing coconut tree. It has two 3W RGB LEDs using, which generate multicolor flashing effects. Also, a tiny 8-pin microcontroller ATtiny85 generates eye-catching colorful LED-chasing effects. It is battery-operated, and the battery is rechargeable so it does not require a power connection through wires. It can be…
How to build a WhatsApp-notifying home security system
A security alarm detects unauthorized entry into a home or building. In the past, these security devices simply triggered a loud siren when an intrusion was detected. As technology advanced, the systems were equipped with GSM modems to send an SMS alert to the home or building owner whenever an intrusion was detected. One drawback…
How to build an Arduino lie detector based on electrodermal activity
A polygraph is an instrument that records physiological indicators like pulse rate, blood pressure, and electrodermal activity of a human subject under questioning by an operator. It’s commonly referred to as a lie-detector test because it’s designed to assess whether a person is telling the truth. Industry-standard polygraph equipment is said to be 80 to…
How to build a MicroPython-based sensorless, weather station
Is it possible to update the weather on an embedded device or a wearable without interfacing with any temperature or humidity sensor? With Internet of Things (IoT) access, devices can connect to a variety of web services with the help of APIs and extract several useful insights and information through simple HTTP requests. In response,…
How to use a buck-boost converter to regulate a Li-ion battery
Nearly every electronic device today relies on a battery as a power source. The dc-dc converter plays a significant role in maintaining the working time of the battery. A buck-boost dc-dc converter is an ideal choice for the most efficient and reliable battery range. The buck-boost converter provides the regulated voltage in the Lithium (Li-ion)…
How to design a smartphone-operated door lock
In this project, we’ll design a unique door lock that can be operated without a keycard, input password, or biometric ID. A smartphone is the key to locking and unlocking the door via Bluetooth. This door uses a solenoid lock, which relies on a latch for electrical locking and unlocking. It also has LEDs to…
How to play a video on an SSD1306 OLED
Small organic light-emitting diode (OLED) displays are commonly used in embedded devices. This is because OLEDs generally cost the same as character LCDs but feature a better user interface (UI) and user experience (UX). Typically, embedded OLED screens are used to display textual messages, but what about videos? For example, is it possible to playback…
Simple overhead tank water level controller without an MCU
In this project, we will learn to create an automatic water pump system circuit that switches ON and OFF based on the water level in the tank. Basic idea The given project demonstrates a simple circuit built using digital logic gates, IC NE555, transistors, and a few additional components that sense the water level in…
Simple data logger system with I2C memory and RTC using Arduino
Manufacturing or processing industries, like textile, chemical, pharmaceutical, and others, have many continuous processes that require monitoring and keeping a record of different physical parameters like temperature, humidity, pH, moisture, flow, viscosity, etc. So, all such parameters are continuously displayed and stored in mainframe computers. Modern industries have DCS and SCADA systems to monitor, store…
How to schedule embedded tasks in Arduino using FreeRTOS
Microcontrollers are limited to certain tasks and typically lack the ability for multithreading, which would allow for more than one user or task at a time without requiring multiple copies of a program or computer. Generally, microcontrollers cannot break larger or more complex applications into multiple threads. They handle straightforward sequences of code in real-time,…
How to build a Node.js server to control Arduino from a webpage
Node.js is the most popular server at this time. Due to its asynchronous and non-blocking nature, Node is the obvious choice for real-time web applications like chat rooms, single-page applications, video streaming, etc. For the same reasons, Node is attracting IoT engineers. As web applications developed on Node operate in real-time, these are best suitable…
How to get input from USB mouse on Arduino
Generally, Arduino boards do not operate as USB hosts; they lack the peripheral as well as RAM to do so . However, it is possible to convert Arduino boards like UNO and Mega2560 to a USB host by using an Arduino USB host shield. With a USB host shield, we can connect almost any USB …
Forest fire detection system using IoT sensor network
In this article, we will be detecting a forest fire using an IoT sensor network and making a portable device with battery operation. Getting information about a fire hazard in a forest in time can prevent the forest fire from spreading. The sensor network can give the particular location of the fire as we already…
IoT-based smart remote classrooms
This project will show how we can use the IoT to create cheap and smart remote classrooms for rural areas using Raspberry Pi and its camera module. If a teacher teaches in a distant city, that session can be streamed live to rural areas. By such applications, children from rural areas can get quality education…
IoT-based, pre-paid electricity system
In this article, we will be making an IoT-based pre-paid electricity system and learn exactly how that works. We will create a meter which will monitor the electricity usage and report to a monitoring server (which we will also create) for bills. In an ordinary electricity system, bills come after the usage, and then we…
Arduino Based IoT Garden Monitoring System
Gardening is a common hobby for nature lovers. The plants need continuous and closely monitored care. Sometimes, this turn into a liability. Like when the care taker of a home garden needs to go out of station for a while, the garden may remain unattended for some time or even long time. The Internet of Things can offer a feasible solution to this.