Electronics for students and hobbyists

(Above) Hall Effect Sensors. View all of my You Tube Videos

Electronics Projects for Students and Hobbyists

by Lewis Loflin

Introduction - The purpose of these pages is to introduce the student and hobbyist to electronics projects. My hope is generate interest for those thinking about entering a high tech field, or simply to have fun.

I've been a part-time adjunct professor at a local community college teaching electricity and electronics. My electronics website reflects what I've taught or been asked to look into by visitors. I have 40 years experience in electronics from vacuum tubes to modern solid state and industrial controls. In college I had a year each of physics, chemistry, and biology along with C, C++. Pascal, and assembly.

I taught myself the coding for Arduino, PICAXE, Raspberry Pi, Microchip PIC, Debian and Slackware Linux, CSS etc. which I approach in a way to give my students a basis for their own projects.

Every page on this website was hand-coded by me - every project built and tested. My education philosophy is learn the basics, find working examples, then use what works as a foundation for further learning. Modify and try new ideas. I'd say my job title would be applied technologist.

TA8050P H-Bridge Motor Control

Optical Isolation of H-Bridge Motor Controls YouTube
Optical Isolation of H-Bridge Motor Controls

Opto-Couplers Theory and Circuits YouTube
Opto-Isolated Transistor Drivers for Micro-Controllers

All NPN Transistor H-Bridge Motor Control YouTube
All NPN Transistor H-Bridge Motor Control

Pulse-Width Modulation Tutorial YouTube
Pulse-Width Modulation Tutorial

PIC12F683 Microcontroller and Circuits YouTube
PIC12F683 Microcontroller and Circuits

Hall Effect Sensors

This included updating the original webpage with expanded material and a new video covering additional circuits.

Basic Hall Effect Sensors YouTube
Hall Effect Sensor Circuits YouTube
Hall Effect Circuits
Ratiometric Hall Effect Sensors

Constant Current Source Tutorials

Each includes webpage and YouTube video. First we cover general constant current source (CCS) circuits ending with the LM334. The using resistive sensors with the LM334. The for higher power CCS for driving LEDs or trickle charge batteries we turn to the higher power LM317.

Constant Current Source Tutorial YouTube
Constant Current Circuits with the LM334

LM334 CCS Circuits with Thermistors, Photocells YouTube
LM334 CCS Circuits with Thermistors, Photocells

LM317 Constant Current Source Circuits YouTube
LM317 Constant Current Source Circuits

First and foremost read this safety warning. Unless one wants to use batteries, the only practical solution is a plug in the wall power supply.

Understand some terms right now: a short is an unwanted connection, while an open is a broken connection. For example a blown fuse is called an open because the electrical path is broken; a short is an unwanted connection such as connecting the positive post to the negative post on a car battery and watching it explode. Yes even low-voltage circuits can explode if mishandled.

Below are quick links to the major sections and projects on this website.

Arduino Solar Power controller with battery box.Arduino Solar Battery Charge Controller

Updates for August 2014 and New Stuff

Solar Panel Battery Charge Controller Using Arduino

Pictures of Power box and Arduino solar charge regulator:
Charge Regulator with Power Box
Connections to Regulator
Inside the Box

You Tube Videos:
More circuitry

Now a available for download a custom live Linux distribution to use a PC printer port for electronics control - without installing or altering the PC in any way.

See Live Linux Distro for Using Printer Port with Electronics

Stepper Motors

Arduino Micro-controller Projects

My Arduino section is growing. For example we can interface the thermocouple amplifier and an LCD display to the micro-controller to display the temperature in say the flue of a wood stove. Again the idea is modular, small projects that can be built into bigger projects. For more technical details on the Arduino see ATMEGA168 Arduino Micro Controller Projects.

Arduino controller
At 3 inches long the Arduino does ten times what the KIM-1 will do.
Cost is under $15.

General Electronics Learning and Projects

Listed below are pages on power supplies one can build and test. At minimum go buy a digital volt-ohm meter. They are cheap and can be found everywhere from Radio Shack to Lowes. In the You tube video I show how to use what I call a load lamp. This is simply a light bulb wired in series with the project. If one connects something wrong or shorts anything out, the lamp will light instead of blowing fuses or burning things out. It will also give one a quick visual indication something is wrong in order to disconnect the power.

Added Dec. 29, 2013:

PICAXE Microcontroller Projects

The PICAXE series of micro-controllers rank as the easiest and most cost effective way to use Microchip processors. I wanted an easier and less expensive way to introduce my students to the "PIC" micro-controller. Here I hope to get those starting out past poorly written literature and lack of simple working code examples.

BOLT Microcontroller LITE with PIC18F2550

Microchip PIC

Update Nov. 8, 2013. I've decide to add Microchip PIC projects to this website in addition to PICAXE and Arduino. Using the 18F2550 BOLT system the programs are largely interchangeable with Arduino. I'll be adding some PIC16F628 assembly language projects a well.

Home Built PIC Development Board
PIC16F628 PIC Using Rotary Encoder to Operate Stepper Motor
Using a Serial ADC with PIC16F628
Calculating Pulse-Width Modulation with a PIC

MAX7219 display controller with 8X8 LED Matrix
Programming the MAX7219 7-segment display with a PIC18F2550
Connecting PIC18F2550 to parallel LCD display

Connecting PC Printer Port to External Electronics

Below are listed a series of projects using pyparallel and electronics. We will use a common PC printer port to learn basic python and electronics interfacing. Starting with routines I wrote to aid students I'd advise walking through this in sequence. Have fun and send comments and/or corrections to lewis@bvu.net.

Printer Port Projects Main Page

Connect Electronics to PC printer Port with Python
Setup PC Printer Port with Python-Linux
Use PC Printer Port to Read Analog Voltage

Read-Write Arduino ADC PWN with Printer Port
Printer Port to Serial LCD Display
Connect Arduino to PC Printer Port for advanced control

Linux Videos

Live Linux Distro for Using Printer Port with Electronics
Using the powerful Rox-Filer system in Linux
Use FEH under Linux for a Wallpaper Setter
How to create Symbolic links in Linux

New section for December 2013: Raspberry Pi and Linux!

Here I concentrated on building a fast Linux based operating system to get some weaknesses in Raspberry Pi.

Raspberry Pi, Arduino, and Learning Linux
Raspberry PI Arduino Advanced Interface
Tkinter with Raspberry Pi and PCF8591 AD-DA Sensor

Useful Resources and Links for Electronics Hobbyists