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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 ...
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 ...
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Multiplexing 7-Segment Display with Raspberry Pi

When working with multiple 7-Segment displays a multiplexing scheme is required in order to simplify the design and save Raspberry Pi I/O pins. Such implementations shown in this design. As can be seen from a schematic diagram 2 7-Segment displays ...
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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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Raspberry Pi and 74HC595 Shift Register

Raspberry Pi I/O capabilities can be expanded by adding one or cascading a number of shift registers. In this design 74HC595 example is shown. 74HC595 is a very popular and relatively cheap IC. There are assembled modules based on this ...
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Arduino with DS3231 Real Time Clock

In this post I’ll show you how to interface a RTC module DS3231 Real Time Clock  with Arduino. This particular module uses I2C protocol to transfer current time to a micro controller. DS3231 library and header files should be installed ...
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Arduino Photoresistor Relay Control with PCF8591 Module

Relay controlled by light intensity can be implemented using Arduino UNO compatible board. In this case Keyestudio UNO R3 and AD/DA module with PCF8591 chip. Similar simpler design is available here. On this particular module a photoresistor and a potentiometer ...
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 ...
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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 ...
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7-Segment LED Display PCF8574 I2C Arduino

Adding a serial data transfer capability to a 7-Segment LED Display can be done by using PCF8574 I/O Port expander with I2C interface. Arduino UNO controls the PCF8574 by sending display codes for each segment. Similar circuit based on PIC16F876 ...