Programming the Arduino

04/01/2021

(this is only "Getting started")

First: Any CPU or Controller is as dumb as a post until you tell it what to do, and even then it is an "Idiot Savant " (most controllers are not "Plug & Play")

Second: The Programmer and the Controller have to speak the same language (Proper "Syntax")

The actual code is initially simply text descriptions of desired actions, and the Compiler is a program that converts the text into machine code for the Controller

Every programmer has their own style and approach to a project at hand.

That style may change somewhat depending on the type of project, and even the language in use.

Every Language has its individual "Nuances", which is a nice way of describing the rules and requirements.

There are however, certain principles which should be considered for anyone new to programming.

• "Linear Programming" should be avoided, except at the very beginning of a project.
• "Modular Programming" should be employed immediately afterward:
  • A "Module" consists of code for a specific task, that can be called on demand by any one place in a routine.
  • There can be "Sub-Modules" that can be called independently or even by other "Modules".
• In-line Comments are very helpful throughout the process to assist in keeping your thoughts straight, and especially when even yourself comes back to a routine at a later date.
• Initial documentation at the top of the routine is good practice:
  • New, and additions to the routine (and date).
  • Changes affected, problems (bugs) solved (and date).
  • Results of interactions with shields or outside peripherals.
  • Notes for "The next thing to try".

Programming Language

The common language for Arduinos is C and C++

Routines for the Arduino are called "Sketches", with the file type "xxxx.ino", and the Compiler expects them to be be in a folder by the same name.

Individual routines are basically in 4 major segments:

• Definitions
• Setup
• Run (by "loop"ing)
• Modules

User-written Modules are usually installed after the loop

// All modules require the void xxxxx and the braces { } to enclose the code

void HeatWater() // Calls the Module for Heating

void Wait(int 3) // Calls the Module Wait, with "3" as a passed parameter

Techniques

/* Comments */

// Comments (to end of line)

Definitions:

byte – int – float – boolean – String

Aid in trouble-shooting your Routine:

• Serial.begin(9600); //(allows comments to be echoed back to the Monitor)
• Serial.Print(" 'Value ' = "); // Print the text --
• Serial.Print(Value); // Print the value of "Value"

Operators:

• Difference between "=" and "=="
• && as "And", ++ as "OR"
• if(xxxx ) == HIGH // do not put a semi-colon here
• { ____ }
• while( ) == LOW
• { }

Pin Setup: { Tri-State / Bi-Directional Transceivers }

• pinMode (SW1, INPUT_PULLUP);
• pinMode(LED1, OUTPUT);

Actions: (Pin Controls)

• if (digitaRead(SW1) == LOW)
• digitalWrite(LED1, HIGH);
• delay(200); // delay 200 milliseconds

LCD Controls:

• #include <LiquidCrystal.h> // alert a system library
• ClearLCD();
• lcd.setCursor(col,row);
• lcd.print ("____");
• Kilroy(__LINE__); // Calls the "Kilroy was here" module for troubleshooting

Sample Sketches (Routines or Programs)

The old adage that says "give me an example:

There are a HUGE bunch of sample Routines (Sketches) included in the Arduino (IDE) Program.

Using the IDE, click on File > Examples > Built-in Examples

Sample Sketch #1: BLINK-RGB.ino - RGB_LED (Schematic), RGB Illustration [ Special, just for this group. A small breadboard, jumpers, and 330 ohm resistors required ]

Sample Sketch #2: QST Project (the one that started it all for me)

Sample Sketch #3: Sequence_Relays (Seed Relay Shield – no LCD)

Sample Sketch #4: Furnace-Conrol (Custom Shield)

Sample Sketch #5: Ping_Pwang (Ultrasonic Transducers)

Sample Sketch #6: Key_Grab (PBs by Analog Input using voltage divider(s))

Downloaded Routines (Sketches) should have the file type ".ino" and be placed in a folder by the same name, without the file type.

The Arduino Compiler expects this.

In the IDE, you should:

• Run "Sketch > Verify" before downloading to Arduino
• Then set "Tools > Port" and "Tools > Board" to make the correct assignments
• Then click on the Right Arrow (or "Sketch > Upload") to send to the Arduino

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