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Bargraph Voltmeter

A simple bargraph voltmeter can be built using 2x16 LCD or compatible VFD display. For Arduino version click here. This design utilizes PIC16F877 microcontroller and its ADC block to convert 0 – 5V input voltage to a binary number shown ...
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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 ...
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Arduino 4 Digit LED 7-Segment Countdown Timer

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 ...
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8×8 LED Dot Matrix Display with Arduino

In this article I’m going to show you how an 8x8 LED Dot Matrix Display can be driven by MAX7219 with Arduino.There are 2 similar designs. PIC16F876 version is  available at this link ,for circuit based on 74HC595 click here.For this project ...
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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 ...
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Arduino Up Down Counter LCD

Up Down Counter design based on Arduino MEGA compatible board is the topic of this article.it uses 2x16 LCD display to show the counter values and 4x3 keypad to input initial 3 digit number.The counter will count Up/Down according to ...
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PWM Fan Controller

Pulse Width Modulation (PWM) is very common technique for controlling cooling fan speed in Desktop PC. In this project PIC16F877A based Pulse Width Modulation  controller was built and tested with 2 fans. 80 mm Coolink SWiF2-80P PWM Fan and Arctic Cooling ...
PCF8574 I2C 8-bit I/O expander Featured Image

PCF8574 I2C 8-bit I/O expander

In this post we’ll review a simple interface for PCF8574 I2C 8-bit IO expander IC and PIC microcontroller. For similar Arduino based implementation click this link. The format of present post is similar to 2 recently published tutorials about I2C ...
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Basic Arduino Frequency Counter

Basic frequency counter capable of measuring 0-5V square wave up to 100kHz can be built using just 2 components: Arduino MEGA board and 2x16 LCD display. For PIC16F876 version click here. Frequency counter code is also very simple. It uses ...
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Arduino 4-Digit 7-Segment LED Voltmeter MAX7219

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 ...