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 ...
Simple IR Proximity Sensor Featured Image

Simple IR Proximity Sensor

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 ...
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 ...
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 ...
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 ...
LED-Battery-Level-Indicator-Featured-Image-Arduino

LED Battery Level Indicator Arduino

LED Battery Level Indicator can be built using Arduino UNO board and 10 LEDs. Similar design that uses 2x16 LCD display can be found at this link. RGB LED variant is here. For Raspberry Pi version click here. I/O lines ...
Basic-Arduino-Frequency-Counter-Featured-Image

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 ...
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 ...
Making a siren using Arduino Featured Image

Making a siren using Arduino

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 ...

Digital Power Supply 0-14 Volt

Digitally Controlled Power Supply from 0-14 Volt based on PIC16F876A will be demonstrated in this post. This is a modification of Digital Power Supply 2.5-12V article and has similar characteristics. The most noticeable difference is the use of PCF8591P I2C Digital to ...