Y variable known when x variable known

[DaveX]

@petercl14

as the values for x and y are already known from the equations, is 'read xny' really necessary

No. I made up that function name and insides to stand in for the complicated stuff that you said you already know how to “download” because we do not have a clue about whatever makes x & y.

@petercl14

do you have a source where I can find more about using readXnY();
useXnY(); ? I have never seen code like this in Arduino before.

Did you read this:

@DaveX

Perhaps stepping back a bit and considering the rest of the program in terms of this might help:

@DaveX

• Planning and Implementing an Arduino Program by @Robin2-- A great way to plan your program to be flexible, easy to read, understand, maintain, and extend. ( Live Sim: Lesson A ... Lesson G )

And especially the tutorial at

Planning and Implementing an Arduino Program

CHAPTER 1 - INTRODUCTION When you are new to programming and the Arduino system it can be very tempting to use one of the example sketches and make changes or add bits onto it to meet your needs. If what you are doing is even a little bit complex this approach will quickly turn into an incomprehensible mess. There are plenty of questions in the Forum that provide vivid examples of this. Adding bits and pieces will probably seem fine as long as you have the correct image of the code in your he…

It does an excellent job of explaining how to build an easy to understand and maintain program by using functions like readXnY() and useXnY() to organize and communicate a thought process behind the programming.

I’m glad you see a way forward because it still isn’t clear to the rest of the world what you need.