How to use a piezo transducer as a tactile switch
If you ever need a robust button for your next project you should really consider using a piezoelectric crystal as a main component. Piezo crystal has a property to generate voltage when mechanical force is applied by bending it, striking or even touching. This crystal is also used in car alarms as a vibration sensor.
In order to turn on a relay or have a transistor output to control some other electronic device, you need to build a debouncer circuit and also to prolong short bursts of impulse coming from piezo. The crystal is simply connected to a base of NPN transistor that will open when piezo generates enough voltage. This impulse if then fed into the NE555 which is in monostable configuration and it will issue a 1 second pulse after being triggered. How cool is that!
Remote RGB LED strip driver with PICBasic
If you have some RGB LED strip leftover from your previous project, do not let it go to waste. Why not building a simple three channel PWM driver with IR remote control support to power it with? It is a great weekend project that anyone can build.
This project is based on an old PIC16F84 we had lying around, three 1A transistors and an IR remote receiver. The firmware is written in PICBasic and is commented out so beginners could learn a thing or two about the way that device works. There are few firmwares available that decode: Nokia remote protocol, Sony and Philips.
Source: Edo Lelic
Electronics of Master Clock for Slave Clocks
Big old wall clocks that were used in facilities such as schools, factories and hospitals are very appealing and will probably never go out of style. They are very durable and almost never break down due to very simple mechanism they have.
This mechanism is actually pretty simple, it is just an impulse motor (two coils) and a couple of gears - no further complications. This is a blessing and also a curse for these antique clocks because for their operation they now require something called a master clock. Master clock is an electronic device that sends pulses to these slave clocks so that they can work.
Source: Edo Lelic
SafeDrop - a safer package delivery invention
Are days of lost packages behind us? Not really, but we might be one step closer to the solution, at least for the local-mail.
[David] managed to create a concept called SafeDrop that could be used by the postal services or local courier delivery agencies for packet delivery. This SafeDrop is actually a locked box filled with electronics that can be unlocked only by the intended packet recipient by scanning the secret barcode. Electric lock is made with servo motor and all electronics are built using the Intel Edison IoT platform.
Maybe it is a hardware overkill at this point, but it sure proves the concept.
Source: David Xie
Cool intercom addon to unlock front door
If you have an analog intercom in your apartment and feel bored every time you need to unlock the doors, this might be your next project!
It is an addition to your analog intercom which is installed in the apartment and is used to unlock the front door by entering a secret passcode. Of course, the passcode is not a traditional numerical one, it actually consists of short and long rings! To make project even more interesting and fun, the author added an audio playback option to play funny lines when wrong passcode is entered.
Croatian Arduino - Croduino by e-radionica
This time we would like to present you with a new Arduino board named Croduino, made in Croatia by e-radionica crew. This is actually a collection of Croduino boards that are fully compatible with Arduino.
One of these boards is a Croduino Basic2 which incorporates ATmega328 and CP2102 USB<->Serial converter. There is also a wearable-duino board called Damba that has Attiny85 onboard. Their latest project is ESP8266 WiFi Croduino module for your next IoT project!
Circuit simulator and PCB design software - EasyEDA
EasyEDA is a free, no-install, cloud-based EDA tool, designed to give electrical engineers, educators, engineering students and electronics hobbyists an Easier EDA Experience. It is easy to use circuit design, circuit simulator and PCB design app that runs in your web browser.
Features of EasyEDA: Cool Schematic Capture - draw schematics quickly using the available libraries on browser. Seamless automatic upgrades; Circuit Simulator - verify analog, digital and mixed signal circuits with spice subcircuits and models; Online PCB Design - with multiple layers and thousands of different pads for smooth PCB layout.
PCBs for Inductive Vehicle Loop Detector available for sale
I am happy to announce that professionally made PCBs for project Inductive Vehicle Detector are available for sale at Elecrow website.
For those who do not know: Inductive Loop Detector works by detecting an inductance change in wire loop (coil) that is buried in road. It does that by measuring the frequency of the internal oscillator which powers the mentioned coil. When a metallic object moves over the coil it changes its inductance and that in turn changes the oscillator frequency which is measured by the microcontroller. It is used for vehicle access control at door and barrier controls, for monitoring the occupancy and for vehicle counting in parking garages, for traffic light installations and traffic controllers, for direction and speed detection of vehicle traffic (if dual channel version is used), in car-wash plants, etc.