Temperature Controlled Fan Featured Image

Temperature Controlled Fan

Here is another fan controller design based on PIC microcontroller, this time it's temperature controlled and can be used to monitor Hard Drive temperature and adjust the fan speed accordingly or as a case fan controller. This post following recently ...
Simple Digital Voltmeter Featured Image

Simple Digital Voltmeter

Simple digital voltmeter can be built by using PIC microcontroller and a few discrete components. PIC16F877A 10 bit ADC module was used for this purpose, we’ll work only with 8 upper bits to translate input voltage to digital form and ...
Digital Voltmeter LED Display Featured Image

Digital Voltmeter LED Display

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 ...
RFID-Security-Access-Using-Arduino-Featured-Image

RFID Security Access Using Arduino

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 ...
High Power LED Controller Featured Image

High Power LED Controller

This post is about building a simple LED controller circuit. Several articles were published on this subject. Here is just one link to similar design that can be useful. Search the site for more information. Current design  relies on well-known technique to ...
Using Ultrasonic Sensor HC-SR04 with PIC16F877 Featured Image

Using Ultrasonic Sensor HC-SR04 with PIC16F877

This post is about building a basic distance meter with ultrasonic HC-SR04 sensor and PIC micro controller. For Arduino version click here. Raspberry Pi variant is also available at this link The interface is very simple and does not require too many commands ...
Binary-to-Hex-7-Segment-Arduino-Featured-Image

Binary to Hex 7-Segment Arduino

In this post I’ll show you how to build a simple Binary to Hexadecimal converter using common cathode 7-Segment display and Arduino Mega compatible Iduino Mega R3 board.  Similar devices should also work ,however I did not test it. The ...
Solar Power Mobile Charger Featured Image

Solar Power Mobile Charger

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 ...
Digital Timer Featured Image

Digital Timer

Digital Timer can be built by using PIC16F876A micro-controller and a few additional components. The schematic is similar to Fan Speed Monitor Design. 3x4 Keypad and 5V Relay were added as you can see from figure below. Only three 7-Segments ...
3.5 Digit 5x7 Dot Matrix LED Display Featured Image

3.5 Digit Dot Matrix LED Display

In this post I'll show you how two QDSP-L149 5x7 dot matrix  LED Displays can be used to create a  4 Digit display module. The trick is to change  the roles of rows and columns. So now each 5x7 Dot ...