Interfacing LCD Display with serial Interface like I2C can save microcontroller I/O making it a practical alternative to a standard parallel 8 bit interface. We’ll use PCF8574 I2C port expander and PIC16F876A microcontroller to establish IIC communication by 2 lines, ...

In this post I'll show how you can drive 7 Segment LED display with PIC16F876A. Instead of using a dedicated IC’s like 4511 we’ll program the micro controller to convert  BCD input code 0 – 9 to a 7 Segment LED ...

This post is about building a 3-digit countdown timer based on Arduino MEGA. Up/Down counter also available at this link. The timer will wait for 3-digit number to be entered via 4x3 keypad and then start counting down to zero ...

This post is about building a simple 0-5V 3 digit voltmeter using Arduino UNO compatible board and 4x20 LCD display. This design should also work on all similar boards, I’ve tested it on Arduino Mega and UNO boards.  No additional ...

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 ...

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 ...

In this article we’ll see how to generate 1 Hz clock with PIC16F876/877 PIC microcontrollers. 3 different approaches will be demonstrated. The most basic solution is to use nested loops to “waste” enough instruction cycle time in order to produce ...

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 ...

Current LED Bar Graph design for Arduino UNO platform uses 16 independently controlled RGB LED’s with integrated WS2812 chip. Similar project is available at this link. In general the voltage is divided into equal intervals equal to the number of ...

Using LM35 temperature sensor with Raspberry Pi is a relatively simple task once you have a way to read and convert analog signals. Fortunately in my previous project I’ve shown how to build a basic Raspberry Pi voltmeter with ADS1015 ...