7-Segment LED Display I2C Featured Image

7-Segment LED Display with I2C

In this post we’ll add a serial data transfer capability to a standard 7-Segment LED Display by using PCF8574 I/O Port expander IC with I2C interface.For similar design based on Arduino see this link. Usually in order to minimize required ...
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 ...
Controlling PWM Fan with PIC16F684 Featured Image

Controlling PWM Fan with PIC16F684

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 ...
Response Time Meter Featured Image

Response Time Meter

If you ever thought how fast you can react to external stimulus here is the circuit that can measure your response time. It measures the time it takes for you to press the push button in response to  turning the ...
Binary-to-Hex-7-Segment-Arduino-Featured-Image

Binary to Hex 7-Segment Arduino

In this post I’ll show you how to build a simple Binary to Hexadecimal converter using common cathode 7-Segment display and Arduino Mega compatible Iduino Mega R3 board.  Similar devices should also work ,however I did not test it. The ...
Digital Alarm Clock Featured Image

Digital Alarm Clock

Digital Alarm Clock design based on PIC16F876A will be demonstrated in this post. Various modules from earlier project were implemented in  current design hardware and source code. For example it uses the same 7-Segment Display and multiplexing routing as in ...
PC Fan Controller Image

2 Channel PC Fan Controller

Following recently published article about building a PWM Fan Controller here is another simple controller design. This time it’s a 2 Channel PC Fan Controller for standard 12V Fans. It uses software implementation of PWM but instead of directly driving PWM ...
PCF8574 I2C 8-bit I/O expander Featured Image

PCF8574 I2C 8-bit I/O expander

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 ...
LED Controller Featured Image

LED Controller

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 ...
High Power LED Controller Featured Image

High Power LED Controller

This post is about building a simple LED controller circuit. Several articles were published on this subject. Here is just one link to similar design that can be useful. Search the site for more information. Current design  relies on well-known technique to ...