This post is about building a distance meter using HC-SR04 Ultrasonic Sensor and Arduino MEGA board. For PIC16F877 version click here. Raspberry Pi variant is also available at this link. HC-SR04 module can measure distances ranging from 2cm – 400 ...

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 ...

This is a modified version of basic wave generator design with AD9850 and Microchip PIC16F microcontroller. A relatively simple assembly code available for download at the bottom of the page. Instead of using a rotary encoder as many other similar available ...

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 ...

A simple wave generator should be a part of every electronics enthusiast toolset. Basic Sine/Square output in reasonable frequency range will be sufficient for general use. Luckily such generators are available in form of a very popular AD9850 module.  Search ...

Light emitting diode (LED) Controller was built using PIC microcontroller and LM317 regulator. Comparing to traditional light sources led illumination should provide more efficient lighting also giving you a possibility to choose desired wavelength. 48 white diffused LEDs connected in parallel ...

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 ...

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 ...

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 ...

Here is another digital clock design based on Arduino platform. This time it uses 4-Digit LED Dot Matrix module to show the time. Similar design with LCD display is available here. The Dot Matrix module consists of four MAX7219 chips ...