Author Archives: R-B

Unlock a door with a tap on your Apple watch

Marc Jensen, James Squires, and Shawn Roske over Make have posted great instructions on making an Apple watch door unlocker using RFduino, which can unlock your front door with just a tap on an app.

Apple watch door unlocker

Apple watch door unlocker

We started this project to help solve a real-world problem: prevent our employees from being locked out of our office. Our security system automatically locks the doors outside of normal business hours. If someone steps out of the office without their security card or keyfob, they’re locked out. When this happens, people use their phone to call or email people at the office to let them back in. This showed us that people may forget their security card — but they don’t forget their phone. With this insight, we set out to create an mobile app that would serve as a virtual security card. The Apple Watch would make this even more convenient, and since Apple Watch apps are extensions of iPhone apps, we created a bundle that includes both apps.

Check out the demo below:

Four phase stepper motor controller

Rajkumar Sharma shares his unipolar 4-phase stepper motor controller board on Electronics Lab website.

C055_1

4-phase stepper motor controller

Unipolar 4-Phase Stepper Motor Controller Board will help you control a Stepper Motor or 4 individual Solenoids. This circuit consisting of transistors that serve as current amplifier and also diode to prevent damaging back EMF, circuit uses Darlington transistors to provide high current capacity to unipolar stepper motor. Just provide sequence of pulse using Micro-Controller or descript circuit to roll out the unipolar motor. On board High Watt resistor to control the current, value of the resistor can be set as per your load current requirement.

Arduino alarm shield

IngGaro‘s entry to the 2015 Hackaday’s Prize contest is an Arduino Alarm Shield that supports NFC and RFID activation with authorization control and can turn an Arduino Mega 2560 board into an anti-theft alarm system.The system is capable of sending email and GSM notifications and can be fully configured through a web interface.

Arduino alarm shield

Arduino alarm shield

The system is composed by a main circuit (the arduino shield) installed in an hidden place and an i2c connected “remote control panel” near the main house door, offering LCD, capacitive buttons and RFID recognition.

The whole system may be managed and configured from the webserver; webpages are published in iphone/android webapp format. When the system is alarmed, it sends mail and SMS to the owner.
It also connects to house domotic system (e.g. close rolling shutters when it’s activated), control IP cams, send push notification, detect humidity and temperature.

Environmental gas sensing and alert system

This environmental alert system uses an array of four gas sensors (one each for methane, propane, carbon monoxide, and smoke) which are connected to an Intel Edison for automatic gas sensing and alerting.

The entire system is powered from a 5V 3A power supply. Each of the four sensors draws upwards of 150 mA, the Edison around 500 mA, and the DotStar LEDs (at full white brightness) up to 2400 mA. Since the DotStar strip will never be fully on or set to white, the 3 amp supply should work just fine. The entire system is switched on via a mini toggle switch. A single green LED is connected via a 330 ohm resistor to the 5V rail to show the power status.

 

An Intel Edison runs the show for the Environmental Alert System. The Edison is mounted on an Arduino breakout board, which makes it easy to read the analog signals from the sensors and potentiometers. The Edison is connected to the 5V rail via a micro usb cable. The Edison has a built-in Wi-Fi radio, which allows it to connect to the internet without the need for any additional hardware.

Environmental gas sensing and alerting system

Environmental gas sensing and alerting system

Simple 3D projection for your cellphone using clear plastic sheet

A very simple 3D holographic projection technique using a clear plastic sheet is described in this instructable from mikroGanesh.

3D

3D holographic projection

You will be amazed at the simplicity of this mechanism and its practicality. Use your smartphone to project 3D holographic images and videos without any modification or 3D goggles. Be mystified by images and videos popping over your smartphone!! All this from a piece of clear plastic sheet

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