PiScope (Raspberry Pi based Oscilloscope)

An oscilloscope is a laboratory instrument commonly used to display and analyze the waveform of electronic signals. In effect, the device draws a graph of the instantaneous signal voltage as a function of time.

Oscilloscopes are used in the sciences, medicine, engineering, and telecommunications industry. Oscilloscopes are very essential and best friend for students, maker, hobbyist and electronics enthusiast. While a digital multimeter can help you measure steady state and RMS (Root-Mean-Square) voltages, the oscilloscope can not only measure peak-to-peak voltages, but more importantly provide timing information on your signal. For instance, have you ever been working with an Arduino controlling a servo motor that has to have just the right pulse width modulation in order to spin clockwise instead of counter-clockwise? During your programming, you may have wondered just how close the pulse width was to what was needed. With an oscilloscope you can measure these pulses. When dealing with analog signals, you can use an oscilloscope to see how close you are to the frequency you need or measure what frequency you need to filter. With so many digital electronic projects, timing between signals is extremely important. Therefore, having an oscilloscope is essential but unfortunately they are very expensive.

 Details of the project

Raspberry Pi Based Wireless FM Microphone

A wireless microphone is a microphone without a physical cable connecting it directly to the sound recording or amplifying equipment with which it is associated. Also known as a radio microphone, it has a small, battery-powered radio transmitter in the microphone body, which transmits the audio signal from the microphone by radio waves to a nearby receiver unit, which recovers the audio. The other audio equipment is connected to the receiver unit by cable. Wireless microphones are widely used in the entertainment industry, television broadcasting, and public speaking to allow public speakers, interviewers, performers, and entertainers to move about freely while using a microphone to amplify their voices.

There are many different standards, frequencies and transmission technologies used to replace the microphone's cable connection and make it into a wireless microphone. They can transmit, for example, in radio waves using UHF or VHF frequencies, FM, AM, or various digital modulation schemes. Some low cost (or specialist) models use infrared light. Infrared microphones require a direct line of sight between the microphone and the receiver, while costlier radio frequency models do not. (-wikipedia)

Once you have the Pi all set up, you’ll be able to amplify your voice with any all-in-one radio or boombox. This could be useful for giving lectures or presentations where it might be hard to hear you and there isn’t a professional PA system. You could also use it in a van or other large vehicle to communicate over the car’s speakers.

Here is the step-by-step instructions how raspberry pi can be used as a very good quality wireless microphone and can be used in class room, seminar, so keep reading. 

For Details Follow the link: 

http://www.instructables.com/id/Raspberry-Pi-Based-Wireless-Microphone/

Arduino & Android Based Bluetooth Controll Password Protected Smart Door Lock (Save your Home)

We everybody are concerned about the security of our home. World becoming smarter and smarter everyday and we want to control and secured our thing in smarter way. In this tutorial I will explain how to made a arduino based DIY smart lock which can be open and closed using password sent from android smartphone by using Bluetooth. 

This smart Lock is the secure, simple, and easy to manage your home’s lock. This lock needs no keys and the lock is attached inside the door and you can control it from outside the door. As the lock is inside the door there is no way to break the door by thief.

You can find some smartphone control lock which required to replace you entire lock system but in my tutorial I will made the thing using your traditional old lock.

This project is based on the android application, android application send password through Bluetooth. An android application is required to open and close the lock and I will explain the details of android app development in the later part of the tutorial. If password is matched to your preset-lock password then lock will be open and sent a feedback to your phone. 

For details please visit : http://www.instructables.com/id/Arduino-Android-Based-Bluetooth-Controll-Password-/