An analogue-to-digital converter (ADC) is an electronic device whose function is to translate an analogue quantity into a digital value encoded on several bits. The converted signal is usually an electrical voltage. As we have explained before, the GPIO pins of any microcontroller board such as Arduino, ESP32 etc can handle digital input or output only. The analogue pins of Arduino are an … [Read more...]
How to Save Sensor Data from ESP32/Arduino to InfluxDB
There are some databases which are suitable for use with Arduino, ESP32 etc microcontrollers. We can indeed use MySQL (and PHP) to create IoT projects like this one. However that approach requires own API server and such method has limitations. It is a complicated method and presents app and web development moving away from PHP and MySQL/MariaDB. These days it is convenient to use Create React App … [Read more...]
What We Have Learned From Titan Submarine Incident
The 2023 accident of the submersible Titan occurred during a dive into the international waters of the North Atlantic Ocean off Newfoundland, Canada. The Titan is a small submersible for tourism purposes, operated by OceanGate and intended particularly to ensure paid visits to the wreck of the Titanic. On June 18, 2023, it began a descent towards the wreckage during which it suffered an implosion … [Read more...]
Arduino 12 LED Meter (Bar Graph) With Potentiometer for Various Projects
There are various ways to create a LED Meter or Bar Graph with a few square LEDs of three colours and demonstrate the function with a potentiometer. There is nothing new with this idea since official documentation of Arduino already has one example of bar graph. However, not all of them are practical to use with every project. The sensors in real often do not generate a voltage (or PWM signal) as … [Read more...]
LED Chaser Effect With PWM Using Arduino
In our earlier article, We have discussed PWM and informed you that this PWD technology is used in particular for light-emitting diodes (LEDs), as they are often used as backlights on mobile phones or brake lights in newer motor vehicles. Our older article on Breathing LED also uses PWM. This was the sketch, LED is attached to pin 11: [crayon-69f3a050293ec979688227/] This article is … [Read more...]
What is Pulse Width Modulation (PWM)?
Pulse Width Modulation (PWM) or Pulse Duration Modulation is a type of modulation in which a technical quantity of electrical voltage changes between two values. At a constant frequency, the duty cycle of a square wave pulse is modulated, i.e. the duration of the pulses forming it. It is used to generate a pseudo-analog signal from a digital or analog environment to allow processing of this signal … [Read more...]
What is General-Purpose Input/Output (GPIO)?
GPIO (General Purpose Input/Output) ports are I/O ports widely used in the world of microcontrollers, especially in the field of embedded electronics. Usage of this term appeared in the early 80s. GPIO are placed on an electronic circuit in order to communicate with electronic components and external circuits. These can be detectors or sensors to capture data, or to control commands. GPIO contacts … [Read more...]
Toggle Button Status Update (PHP, MySQL, AJAX)
Our This guide ESP32 Arduino IoT Relay Control is self-hosted. The working result is here. This kind of project serves the purpose but the UI is just pathetic and you can not easily convert it to an Android or iOS app. Most of us want a working system to get a toggle button control like this one. These days, you have a lot of options for UI such as React.js or just Twitter Bootstrap. You have … [Read more...]
What is Cathodoluminescence?
Cathodoluminescence is a special form of luminescence in which an electron beam coming from an electron source hits a solid surface and stimulates it to emit light, i.e. electromagnetic radiation (functional principle of cathode ray tube). In geology, mineralogy and materials science, an optical cathodoluminescence microscope is used to visualize internal structures of rock samples, ceramic … [Read more...]
Arduino TDA7297 Audio Amplifier Module (for Doorbell)
Our Arduino project on doorbell is a great, simple project but if you followed that guide, you have probably noticed the volume of the sound that we are generating using a buzzer or speaker connected to an Arduino is not enough loud to be useful as a doorbell. That's why we need to slightly modify such projects and amplify the sound. TDA7297 amplifier module can be powered by 6-18V and is … [Read more...]
Arduino LED Blinks with Pushbutton Pause
We have published several simple articles on Arduino, LED and pushbuttons. They are a great learning tool for the children, as well as great "templates" for the adults to start a new project. Here is a list of some of the old articles: Arduino 2 Push Button One LED: Switch On/Off Make Beep Sound in Arduino Project Upon Push Button Press Arduino Blink LED Rate Depending On Push Button … [Read more...]