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 ...

3 Digit Dot Matrix Display with SPI interface is an advanced version of recently published 7x5 Dot Matrix Character Generator project. This design is more complex as it contains 4 microcontrollers. Three PIC16F88 were used to control 7x5 Dot Matrix Displays, ...

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 ...

In this post I’d like to share a design of PWM Fan controller based on PIC16F684 MCU. For Arduino version click here. Previously I’ve designed similar circuits some of them more complex than this one. I recommend you to look ...

Generating Sine wave is a relatively simple task. It can be done by adding MCP4725 12bit DAC to Raspberry Pi. For Arduino version based on PCF8591 IC click this link. This setup is based on I2C interface and works by ...

In this post a 1 axis basic digital level design will be presented. This circuit is based on Arduino UNO board and MPU6050 accelerometer and gyroscope chip. The communication is done using I2C interface. MPU6050 module address can vary depending ...

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 ...

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 ...

Here is a modified and improved electronic lock design. For Arduino version click here.It is largely based on Digital Lock article, however this time a real electronic lock was used instead of a solenoid. The code is a 4 digit number ...

In this post I’ll show you how a 12 bit DAC model MCP4725 can be connected and controlled by Arduino or a compatible board. Similar design based on Raspberry Pi platform can be found at this link . Wire.h and ...