A variable bench power supply is an important equipment in electronics lab for conducting experiments, prototytyping, and testing. This cool-looking DIY bench power supply provides fixed 5V and 12V outputs along with a separate variable DC output ranging from 1.2 to 25V. The on-board LCD display shows instantaneous output voltage, current, and power drawn, which are very important parameters during prototyping of a new project. The power supply can also be connected to a PC through RS232 port to visualize and monitor these parameters graphically on screen. The project uses Atmega8 microcontroller for measuring and displaying the electrical output parameters.
DIY variable power supply
Here is a nice instructable on building a Bluetooth-controlled dual channel relay switch using Atmega328 MCU and a cheap HC-06 Bluetooth module. You can use this device to control various appliances and devices in your home by sending commands through any Bluetooth device.
Bluetooth-controlled relay switch
The easiest way of producing a sound using an Arduino board is by bit-banging its I/O pin driving a buzzer or speaker. However, if you want to go beyond simple beeps and synthesis complex and more interesting sounds, you need a better understanding of the Arduino hardware as well as the theory behind wave synthesis. Here’s a wonderful tutorial from Makezine that describes the fundamental concept of synthesizing waveform and how to manipulate it in real time.
Arduino sound synthesis
This Instructable describes the hardware hacking of Stainley’s remote controlled power outlet and modifying it to make it controllable through web or smartphone using Electric Imp. The Electric Imp is a WiFi enabled development platform powered by a Cortex-M3 processor core enclosed inside a tiny package that looks like a SD card.
Electric Imp controlled power outlets
The Electric Imp is the core of the system operation. When the button on the Web App is activated, an AJAX HTTP Request is made to a URL specific to your Imp. This request is sent to the Imp Agent in the Electric Imp cloud that is specifically associated with your Electric Imp. The Agent code is a mini Web Server that parses the request and if valid, passes it on to your Imp firmware via the cloud. This behind the scenes communication between the server based Agent and the hardware based firmware was developed by the talented people over at Electric Imp. Read More
The 12F series of PIC microcontrollers are handy little 8-pin devices designed for small embedded applications that do not require too many I/O resources, and where small size is advantageous. These applications include a wide range of everyday products such as hair dryers, electric toothbrushes, rice cookers, vacuum cleaners, coffee makers, and blenders. Despite their small size, the PIC12F series microcontrollers offer many advanced features including wide operating voltage, internal programmable oscillator, 4 channels of 10-bit ADC, on-board EEPROM memory, on-chip voltage reference, multiple communication peripherals (UART, SPI, and I2C), PWM, and more. Today we are introducing a new development board (rapidPIC-08 V1.0) for easy and rapid prototyping of standalone applications using PIC12F microcontrollers.
Rapid PIC12F Series Microcontroller Development Board