Jason Hamilton has built this Arduino-based RFID access control to open his garage door using RFID. The project has a master RFID key hard-coded into the Arduino firmware, which allows you to add other keys to the system. The new keys are all stored into the EEPROM memory of Arduino.
Arduino based RFID access control for doors
This application note from Microchip provides a detailed analysis of driving a single and multi-phase AC induction motor using the 8-bit PIC microcontrollers. It shows how to build a low-cost three-phase inverter circuit using PIC16F1509 to add speed control and soft-start to a single and multi-phase AC induction motor.
AC induction motor controller
This 12V DC booster circuit uses the MC34063A device which contains all the primary functions required for DC−to−DC converters. It has a built-in temperature compensated reference, comparator, controlled duty cycle oscillator with an active current limit circuit, driver and high current output switch. It operates from 3.0 to 40.0V DC and can supply output current up to 1.5A. This booster can thus power your 12V load with a 3.7V Li-Ion battery.
DC-to-DC booster using MC34063
Lock-in amplifiers are used to detect and measure very small AC signals which are buried in an overwhelming noise. For example, consider a case where you want to single out a 5 mV sine wave from a white noise signal with 2 V amplitude. A lock-in amplifier makes this measurement possible. It uses a technique called phase-sensitive detection, which uses a specific frequency reference to extract the component of the signal at the reference frequency and phase. Noise signals, at frequencies other than the reference frequency, are then rejected and do not affect the measurement. This instructable describes how to construct a very simple lock-in amplifier using Anlog Devices’ AD630 high precision balanced modulator. The overall cost of this lock-in counter is around $60.
DIY lock-in amplifier
MikroElektronika, a Belgrade, Serbia-based company, which is widely known for manufacturing a wide range of microcontroller development boards and compilers, is celebrating 10 years of success in compiler development this month. They developed their first compiler, which was mikroPascal for PIC, in 2004, and since then they have released total 18 compilers: mikroC, mikroBasic and mikroPascal for PIC, dsPIC, PIC32, 8051, AVR and ARM. They are celebrating a decade of their achievement by offering entire month of special discount towards purchase of their BASIC, PASCAL, and C compilers. Throughout this month you can save up to $100 on the purchase of license for their compilers, and if you are lucky you can even win a free license by entering the sweepstakes.
MikroElektronika completes 10 years in compiler development