By T.K. Hareendran

International Electronic Design Freelancer • Technical Author • Hardware βeta Tester • Product Reviewer
Articles Written 469

Backpack LED Patch (v2)

After posting the Backpack NeoPixel LED Safety Light project (https://www.codrey.com/arduino-projects/backpack-neopixel-led-safety-light/), I received a lot of requests to publish another do it yourself project based on regular light-emitting diodes, instead of using NeoPixel LEDs. So, I […]

Sound Reactive Pixel LEDs

This little post covers the construction details of sound reactive pixels which is pretty enjoyable to build and watch. You can embed it in a lot of things, for example, think about gluing it in […]

USB Cigarette Lighter Teardown

I was after a cheap windproof electric lighter to use in and around the home. Well, they are cheap enough to buy heaps of them, so I bought a pair of USB cigarette lighters to […]

Arduino Portable Ultrasonic Distance Meter

After a little bit of research, I discovered that building a portable ultrasonic distance meter using Arduino was indeed a very simple task. I was surprised to discover that integrating a tiny OLED display into […]

Arduino Light up Coaster Ideas (v1)

Now is the time to make something that lights up! As promised in one of my previous posts, I’m sharing some crude design ideas for making your own coaster that wakes up as it listens […]

Raspberry Pi Pico – PWM Primer

Sometimes ago I wrote an introduction to Raspberry Pi Pico. Today I will show how to exploit its pulse width modulation features. However, if you want to do some serious projects starting from this blog […]

Raspberry Pi Pico – Quick Start

Raspberry Pi Pico is a microcontroller board from the Raspberry Pi foundation. It is an exciting new microcontroller board launched on January 21, 2021, based on the RP2040 micro-controller by the Raspberry Pi Foundation sporting […]

Arduino & Square Wave Thoughts

The theory behind generating square wave is almost a trivial thing! A square wave is a signal that changes between high and low state where the primary requirement is that the on-time (high state) and […]

Reverse Voltage Defender – Design Ideas!

This article shows you how to use reverse voltage protection with minimal power loss in your electronics projects running on a battery/DC power supply. In fact, for a long time, I wanted to put together […]