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Showing posts from October, 2015

How to Change or Customize Windows 7 Boot Screen Using Windows 7 Boot Updater

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By:Prayag Nao

Now the wait is over. Since when Microsoft released Windows 7, no one was able to change the boot screen as it requires lots of files and certificates customization.

But now Jeff Bush @ "Coder for life" website has developed an excellent tool which can customize Windows 7 boot screen.

"Windows 7 Boot Updater" is a program that makes it easy to update the Windows 7 boot animation and text. It is written in C++/CLI and requires Microsoft .NET Framework 2.0 and the Microsoft WIM library.

Features List:
Modifies the boot animationModifies the boot text "Starting Windows" and "Microsoft Corporation"Will compile the animation from 105 BMP, PNG, GIF, or TIFF imagesDoes not require any other applications (like ImageX)Designed to be idiot-proof by having numerous checksAutomatically backs up the modified filesWorks for all versions of Windows 7: any language, any edition, 32-bit or 64-bitWorks even if your setup has the hidden "Sys…

Interfacing HC-SR501 PIR Motion Sensor with Raspberry Pi

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By:Prayag Nao

All living beings radiate energy to the surroundings in the form of infrared radiations which are invisible to human eyes. A PIR (Passive infrared) sensor can be used to detect these passive radiations. When an object (human or animal) emitting infrared radiations passes through the field of view of the sensor, it detects the change in temperature and therefore can be used to detect motion.
HC-SR501 uses differential detection with two pyroelectric infrared sensors. By taking difference of the values, the average temperature from the field of view of sensor is removed and thereby reducing false positives.
Interfacing HC-SR501 with Raspberry Pi is easy because the output of sensor is Pi friendly ie. 3.3V and it can be powered from the 5V rail of  Pi.

The PIR sensor consist of 3 pins:

Vcc – 4.5V to 20V, Input powerOUTPUT – TTL output of sensor 0V, 3.3VGND Ground Working of HC-SR501 PIR sensor
The module has a rectangular window with two sub probes 1 and 2 locat…

Interfacing HC-SR04 Ultrasonic Sensor with Raspberry Pi

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By:prayag nao

Ultrasonic distance sensors are designed to measure distance between the source and target using ultrasonic waves. We use ultrasonic waves because they are relatively accurate across short distances and don’t cause disturbances as they are inaudible to human ear.
HC-SR04 is a commonly used module for non contact distance measurement for distances from 2cm to 400cm. It uses sonar (like bats and dolphins) to measure distance with high accuracy and stable readings. It consist of an ultrasonic transmitter, receiver and control circuit. The transmitter transmits short bursts which gets reflected by target and are picked up by the receiver. The time difference between transmission and reception of ultrasonic signals is calculated. Using the speed of sound and ‘Speed = Distance/Time‘ equation, the distance between the source and target can be easily calculated.


HC-SR04 ultrasonic distance sensor module has four pins :
VCC – 5V, input powerTRIG – Trigger InputECHO – …