9 Volt Battery Charger Featured Image

9 Volt Battery Charger

9 Volt batteries extensively used in various electronics measurement equipment. Powering these devices with  rechargeable batteries can be a cost effective solution. In this post a simple Lithium-ion 9 Volt Battery Charger design with overcharging protection will be presented. Charger is ...
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 ...
Function Generator Featured Image

Function Generator

Have you ever wondered how to generate a sine wave using PIC microcontroller. In this post I’ll show you a simple circuit design that can generate arbitrary wave forms including sine by using MCU and PCF8591 D/A converter. For similar design ...
Solar Tracking System Featured Image

Solar Tracking System

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  ...
Wireless UART Featured Image

Infrared UART

Wireless Infrared UART prototype can be built by using two PIC16F876A controllers. One as IR receiver with dedicated Infrared decoder like SFH505A, SFH506 or similar IR receiver IC and other microcontroller as a transmitter via IR LEDs. This is relatively simple ...
Raspberry-Pi-3-Digit-LED-7-Segment-Countdown-Timer-Featured-Image

Raspberry Pi 3 Digit LED 7-Segment Countdown Timer

Multiplexing 7-Segment display scheme with Raspberry Pi as described here can be used as a basis for more complex projects. By adding 4x4 keypad matrix and replacing individual 7-Segment displays with a common anode 4 digit 7-Segments module a simple ...
Fading-LED-with-PCF8591-Arduino-I2C-Featured-Image

Fading LED with PCF8591 Arduino I2C

Controlling LED brightness with Arduino is one of the basic circuits you can built. Fade sketch is even included in the basic examples in the Arduino IDE. However on Arduino boards it’s done by pulse width modulation, changing the duty ...
Arduino-3-Digit-Timer-with-LED-Display-Featured-Image

Arduino 3 Digit Timer with LED Display

Arduino based 3 Digit Timer with LED Display module is a relatively simple design. Recently I’ve published a number of similar projects that essentially perform the same task. You set up an initial value via some kind of user interface ...
LCD-voltmeter-based-on-ADS1015-with-Raspberry-Pi-Featured-Image

LCD voltmeter based on ADS1015 with Raspberry Pi

LCD voltmeter with Raspberry Pi and ADS1015 is the topic of this project. Similar design for Arduino platform is available at this link. ADS1015 is a 12 bit ADC chip with 4 analog input channels. The interface with Raspberry Pi ...
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 ...