Arduino software flow control

Arduino program is single threaded and sequential. Single threaded means lines of codes are executed one code at a time, while sequential means onecode line is executed after another. As stated above, the arduino code executes sequentially one after the other down the code lines, however, situations may arise in a program where the program execution is expected to jump steps or return backwards even without getting to the last line of the code, even in situations like this, the rule of thumb is that the program flow must remain logical without errors.

To tackle such situations, we need to structure the program in such a way that the flow will be logical and error free using structural logical statements to control the program flow. The control structure tells how the codes are organized to enable the program take actions based on certain conditions. This is seen especially when certain conditions are present in a program, just as the one stated above. In other to realize a smart and effective control structure in arduino programming we use control statements.

Control statements are elements functions in a source code that control the flow of program execution, either to wait, jump, repeat, etc. IF statement is basically the simplest form conditional control statements, it is a conditional statement. An if control statement is basically the type of control statement used to program dark activated street lights, the statement evaluates if the environment is dark or not, if the environment is dark, the if statement code instructs the microcontroller to execute a code instruction that will turn on the street light, and if the environment is not dark, the if statement code instructs the microcontroller to execute a code instruction that will not turn off the street light and keep it off until the environment gets dark.

Check the sketch below. The sketch in the image above is better than the sketch that has only if statement for designing the dark activated street light. See image below. For statement is also a conditional statement for arduino control structure used for repetitive operation. As the name implies, it is used to carry out a repetitive operation for a true condition.

For statement gives a condition and checks if the condition still holds, if it does, an action is taking and a repetition can take place, this will keep happening until the condition no longer holds the action that is tied to the condition stops being executed.

This can be used to increment an event. For instance, we can use a For statement to fade an LED up and down. Usually, for loop is used to repeat a block of code enclosed within curly braces. Click the donate button to send a donation of any amount. In this first part of the Arduino programming course, we look at the basic structure of an Arduino sketch and the top-to-bottom execution of program instructions or program flow.

Functions will be covered in more detail later, for now you will just need to know the following about functions:. It is a programming tradition to write a "hello world" program whenever starting to learn a new programming language. The "hello world" program simply writes the text "Hello, world! The purpose of this program is to verify that your programming environment is properly installed and working. If your "hello world" program works, then you are ready to start learning the new programming language.

The Arduino doesn't have a screen to write the "hello world" text to, but we can use the USB port and serial monitor window. Click the Upload button to load the program to the Arduino. Can't see the video? Anything in the above lines of code that is typed into the IDE window incorrectly will most likely cause a compile error, so be sure to type everything in exactly as it is shown in the code above. The program is compiled when the Verify button the tick icon or the Upload button the horizontal arrow icon is clicked.

In this example, the semicolon ; was left off the end of this line: Serial. In an Arduino sketch, program statements individual lines of code are executed or run from top to bottom. This top-to-bottom execution of statements can only be altered by flow control statements. The image below shows the parts of an Arduino sketch.

Statements are lines of code that are executed as the program runs. Each statement is terminated with a semicolon. In the hello world sketch, statements in the setup function are run first, from top to bottom.

The statement Serial. That absolutely precludes using the String class, which gets slower and slower the larger the amount of data it is manipulating gets. You make a request. You push that request type in a queue. PaulS: You make a request. So either process the Serial. Giving up.