RPi 3 BLE Cat Door

RPi 3 BLE Cat Door

“IoT Cat Door using a Raspberry Pi 3, Node-Red and BLE tracking tags! The goal of this project is to build an IoT style motorized pet door so we can control which animals can come into the house. For this we are using BLE tags attached to the animals (cats) and the built-in Bluetooth module on the Raspberry Pi 3 …

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Make a Talking Security Alarm with a PIC16 and ISD1820

Make a Talking Security Alarm with a PIC16 and ISD1820

“Alarm circuits are common in the field of hobby electronics, typically utilizing a switch (such as a reed switch) and a speaker to produce an alarm. However, the alarm system in this project has several unusual features that will be able to fool most intruders. In this DIY Hacking project, we will make a security system that will fool intruders …

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Retro Prototyping, Great for Teaching

Retro Prototyping, Great for Teaching

“Have you ever wondered where the term “Breadboard” came from? Here’s an example of what breadboards were all about. In the early days of electronics, components were large and cumbersome. They didn’t have transistors or integrated circuits, only vacuum tubes. So it was common practice to build prototype circuits on a block of wood using nails or screws …

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Retro Electronics: DIY Resistor-Transistor Logic Gates

Retro Electronics: DIY Resistor-Transistor Logic Gates

“We all love our modern devices ranging from smartphones to smart cars and all of it is made possible thanks to the transistor! The technology we use has only been around for a few decades, so how did engineers in the past create complex digital circuits? This also brings up the question “how did NASA build a computer that was …

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Easy Way to Make a Powerful Joule Thief

Easy Way to Make a Powerful Joule Thief

“Hey nice to see you again guys! Now I’m back with another instructable. I shall teach you how to make a diy joule thief. This is one of the easiest way to make a joule thief and the most powerful one. For those who don’t know what a joule thief is, it’s a small circuit that is …

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How to make FM transmitter

How to make FM transmitter

“A short range FM transmitter is a low-power FM radio transmitter that broadcasts a signal from a portable audio device (such as an MP3 player) to a standard FM radio. Most of these transmitters plug into the device’s headphone jack and then broadcast the signal over an FM broadcast band frequency, so that it can be picked up by …

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Joule Thief With Ultra Simple Control of Light Output

Joule Thief With Ultra Simple Control of Light Output

“The Joule Thief circuit is an excellent entrée for the novice electronic experimenter and has been reproduced countless times, indeed a Google search yields 245000 hits! By far the most frequently encountered circuit is that shown in Step 1 below which is incredibly simple consisting of four basic components but there is a price to be paid for this simplicity …

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