The variable for our “for”-loop can be defined in the “for” statement, So “A” is an unknown variable in line 10, meaning it’s undefined (declared).
#ARDUINO WHILE LOOP BUTTON CODE#
The “scope” of “A” will be the “for”-loop’s code block. Remember the “Scope” of a variable, as discussed in Part 3? println (A ) // this is the line that produces an error! If we would take our previous example, but instead of counting from 1 to 5, we now want to count down from 5 to 1, then our code would look like this: Stick with the rule that the compound operatorsĪre always placed behind the variable in a “for” loop.ĭid we just say “counting down”? Yes we did!Ī “for” loop can also count down, by using the “––” compound operator. Now you know why I am not a fan of using these compound operators – especially in the beginning they can be very confusing. This effectively means that we work with the “old” value of “A” in the code block, but once the code block has been completed, A will assume the new (increased) value. “A++” means: “ increase the value of A by 1 and return the old value of A“. You will have to keep in mind that the “A++” is one of those confusing Compound Operators as we have seen in Part 3. The next thing you will see is that we create an accolade enclosed code block – the same way we have seen it with the “if” statement.Īnything in that code block will be repeated as long as the conditions are being met for the “for” loop. Since we just called those parameters, we need to put round brackets around them, as we have seen with other functions that get parameters (like for example Serial. Or in other words: a data type than can be enumerated (counted in whole numbers and with fixed increments). For each time we go through the loop, increase A by one (A++)Ĭounting in a “for” loop can only be done with whole numbers (byte, int.The parameters we need to give the “for” statement are: Serial.print ( "Switch lights on for light " ) If you’d like, you can forget about the lingo right away though. We cannot use this pseudocode in our program, but it helps writing down the steps we want to take in our program, or to explain code in a more human readable way. Pseudocode is basically writing a program (on paper for example) is a more human like language, yet using “constructs” that look like the ones we use in our programming language of choice. Writing program code like that is also called “ Pseudocode“. Quite often, variables are used for counting, so our previous statement could be: Loops are used to repeat certain instructions repeatedly A bonus is that when we have to change our code to more or less lights, we simply modify one single number. It’s not just for our typing that this saves space – your source code will be shorter and easier to read, but also the compiled program for the Arduino will be much smaller, and maybe even faster. Tada! We’ve just made a loop, which saves us writing down the (almost) same sentence over and over again.Ĭan you imagine how much typing that would save us if we would have to count to 1,000 ? So we repeat the same instruction (switch light ON), for each of the 5 lights.Ĭount from 1 to 5, and for each of the numbers, Switch Light ON.
Say we have 5 lights, each with their own switch. The most common application is when we have to repeat a certain set of instructions repeatedly, either based on conditions or based on counting. The purpose of Loopsīefore we start working with loops, we should probably understand when and where we would be using loops.
#ARDUINO WHILE LOOP BUTTON FULL#
(towards the end of the page he has a circuit diagram and full code example).A complete overview of this course can be found here: Course Overview.
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