MAX7219 is a serial input/output common-cathode display driver. It can interface the microcontroller to 7-segment numeric LED displays, bar-graph displays, dot matrix display or  individual LEDs. This IC has some very useful features like built in decoder, multiplex scan circuitry, ...

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 ...

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 ...

Here is another Arduino based design and this time I’ll show you how a 4-Digit Code Electronic Lock can be built with Arduino Mega or compatible boards. For similar design based on PIC16F877 click this link. The I/O I’ve used ...

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 ...

In this post I’ll show how to build a basic kinetic watch winder using PIC microcontroller and stepper motor. Kinetic watches do not require changing the battery as frequently as in quartz watch however despite their many advantages they have ...

The topic of this post is building sine wave generator based on Arduino UNO and PCF8591 8-bit A/D and D/A converter. For similar design with PIC micro-controller look at this link. Raspberry Pi version based on MCP4725 DAC available at ...

In this short tutorial we’ll learn how to control PCF8591 I2C 8-bit A/D and D/A converter with PIC microcontroller. PCF8591 was already used in a number of recently published projects like Function Generator, also I’m planning to add it to ...

This implementation of Arduino based PWM Fan Controller is simple circuit that allows controlling fan speed by varying the duty cycle of the output signal. For PIC16F684 version click here. I’ve tested with Deepcool 120mm fan and it works OK, ...

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 ...