In this post I’ll show you how to build a RFID reader for security access based on Arduino MEGA board. The code I've used is a modified version of a design that was published at Arduino project hub. I added ...

Light emitting diode (LED) Controller was built using PIC microcontroller and LM317 regulator. Comparing to traditional light sources led illumination should provide more efficient lighting also giving you a possibility to choose desired wavelength. 48 white diffused LEDs connected in parallel ...

Solar power mobile charger can be built by tweaking digital power supply schematic. The Software/Hardware stayed almost the same as the original circuit.Current design has the same overcurrent protection and output voltage can be changed by pressing SW1. Voltage and Current ...

Due to popular demand I've modified digital clock design to work with LCD display instead of 7-Segment LED as described in this post. For Arduino version click here. All the capabilities of LED version have been maintained in current project. 1 ...

Following recently published article about building a PWM Fan Controller here is another simple controller design. This time it’s a 2 Channel PC Fan Controller for standard 12V Fans. It uses software implementation of PWM but instead of directly driving PWM ...

Recently I was asked to build an aquarium lighting controller prototype to provide variable brightness during its operation and ability to program  ON/OFF times. 25 blue and white diffused 10mm LED were used to illuminate the aquarium. The main requirement from ...

Here is another version of Arduino based voltmeter. This time it uses 4-digit 7-Segment LED display and MAX7219 Display Driver. For similar design with 2x16 LCD display click this link. Also you can look at PIC16F876 implementation in my previous ...

A simple light sensor can be built using a photoresistor and Arduino UNO board. Similar design is available here. This design requires only a few additional components like 10k resistor and a 10k potentiometer to adjust the light intensity level ...

MAX7219 is a serial input/output common-cathode display driver. It can interface the microcontroller to 7-segment numeric LED displays, bar-graph displays, dot matrix display or  individual LEDs. This IC has some very useful features like built in decoder, multiplex scan circuitry, ...

LM75A is a digital temperature sensor with built in analog to digital converter and I2C interface .It can provide an accurate temperature reading from -55 to +125 C. For similar design based on analog LM35 sensor click here. Also a ...