Raspberry Pi Things

Traffic light is a simple popular teaching application. Not surprising traffic light applications come up with Raspberry Pi in various ways as described here. Usual Traffic Light :   Red=Stop,  Yellow=Warning,  Green=Go  but still these traffic lights do not work the same way in all countries.   Ex:  Austrian traffic light  vs  US traffic light    Trivia :  History of the Traffic Light Options(HW/SW) for traffic lights on RPi:  LEDs using just GPIOs  - 3 LEDs on different GPIO pins  Step 1: 1 Blinking LED Gordon Projects  1: A single LED   (command shell, photos/Fritz) Raspberry Pi Things   RPi Blinking LED   (command shell, breadboard/ pin photos) Project 2: Flashing Single LED (Python, Fritz) Alternate Python example Introduction to accessing the Raspberry Pi's GPIO in C++ (sysfs) Blinking LED on Raspberry Pi using C Creating a “Blinking LED” project for Raspberr...

Goal : Simple LED to Raspberry Pi 3 B wiring set-up to use with various tests like 4DIAC. Side Goal: Learn some basic electronics so not always asking EE with 4DIAC - how, why LED wiring used http://www.resistor-calculator.com/ LED Resistor Value Calculator    LED used is 5mm,  so chose a 330 Ohm resistor greater than minimum needed. Raspberry Pi 3 Model B v1.2 Pin layout 2 Tests for + output to LED: 1. Pin 1 = 3.3 V output to LED 2. Pin 7 Output to LED: GPIO04   Pin 6 GND was used for - output ground. https://www.jameco.com/Jameco/workshop/circuitnotes/raspberry-pi-circuit-note.html https://www.raspberrypi.org/documentation/usage/gpio-plus-and-raspi2/ sysfs from term command line What worked: To have authority to do commands sudo su [Note: sudo -i   for root environment, suggested, but internet posts indicate it can cause problems easier.] For GPIO pin using to test and change on/off: Test with GPIO4  (note: ...