Ultrasonic transmitter circuit using IC 555

Ultrasonic waves are defined as the sound waves whose frequency is greater than 20Khz and it is not audible to the normal human ears. This ultrasonic possess wide variety of applications from industries (to detect flaws in machineries ) to medicine(for treating and detecting ailments). In fact some animals like Bats, dolphin etc uses these waves to interact with the external environment. This circuit demonstrate constructing a simple 40KHz ultrasonic transmitter built around timer ic 555.

Clap activated light circuit

Clap activated circuits are  something which is used to activate or turn on by means of a simple clap. You might have seen some of this before but building one could be really fun. This clap activated switch circuit can be used for any means of activation not just to turn on the lights. Let's look into the working of this cool  circuit.

How to program I2C protocol in ARM Microcontroller

i2C-programming-tutorial- in-arm-microcontrollers
I2C (Inter Integrated Circuit) also known as TWI (Two wire Interface) is a bus interface connection that is used in many devices such as Sensors, RTC and EEPROM. Unlike SPI this protocol only uses two wires to establish the connection and hence known as Two wire interface. This protocol will come in handy when the designer needs to conserve the number of pins used to perform the communication. This tutorial will teach you to program I2C protocol in ARM7 Microcontrollers.