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 ...

Arduino 4 Digit LED 7-Segment Countdown Timer based on Arduino MEGA will be shown in this post.  For LCD version of this design follow this link. Similar project that uses PIC16F876 MCU can be found at this link. Raspberry Pi ...

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, ...

Raspberry Pi based Digital Clock with 16×2 LCD display is a relatively simple project.It requires only a small set of components and can be completed in less than an hour. Previously I’ve published similar designs based on other popular platforms ...

Here is another modification of a digital voltmeter. This time with 7 – Segment LED Display. These circuits seems to be more popular than other designs so I’ve decided to  publish another variant. You can find 4 variations of digital voltmeter on ...

This post is about building a Simple IR Proximity Sensor based on PIC16F877a micro controller. Usually these simple circuits are built using discrete components and include an OP AMP for comparing the photo diode voltage to a preset value. 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 ...

Fan Speed Monitor is another simple design based on PIC16F876A microcontroller. Two similar posts about ways of controlling and monitoring fan speed were recently published. PWM Fan Controller and 2 Channel PC Fan Controller. Current article however implements a different ...

This post is about designing a simple PIC microcontroller based Solar Tracking system. It requires some basic electronics skills and good motor coordination. This design uses 2 unipolar stepper motors and 4 IR-850nm LEDs as sensors to follow the sun  ...

Generating sound patterns with Arduino is a topic of this article. All you need is Arduino compatible board a simple DC buzzer and current limiting resistor. In this project I'll show how to build a police siren using Arduino Mega ...