Pressure gauges are used in industries such as oilfields. I have used pressure gauges many times in my day time job, especially when dealing with hydraulic machines. And I was wondering how can I make a virtual pressure gauge.

This project is a 2-part project. In Part 1, I will make a virtual pressure gauge, and I will control the pressure using the up and down keys of the keyboard. In Part 2, I will use the same pressure gauge that I have made in Part 1 and this time I will control it using an external circuit with Arduino. It is not a complicated project. very easy to make and it was fun to make as well.

Supplies

For the Part1, you only need a computer PC or Mac, it does not matter which one you use, I'm using PC for this project.

Access to the internet is required to download pictures at google image
You will need to download the processing language as well, you can find it on this link https://processing.org/download/

Step 1: Step 1: Download a Picture of a Pressure Gauge at Google Image.

I will start this step with some assumptions.

1. I will assume that you already have installed processing language and you familiarized yourself with it. processing is a sister language to the Arduino language, it should not be difficult to understand, plus you can find some tutorials on the website, from my point of view, it is a very easy programming language.

Once you feel like you are familiar with processing language, you need to go to google and look for a pressure gauge picture, you will find a lot of them, you just have to pick the one you like. I picked this one because I liked it, it's simple and it has no brand on it.

Step 2: Step2: Erase the Needle.

Once you have picked your picture, you will need to do editing.

first, you completely erase the needle.( I suggest you keep a copy of the picture of this gauge with the needle on, because you will need it).

You can use whatever picture editing software you like. I have used to paint 3D.

Step 3: Step 3: Design of the Needle.

in this step, we will develop a small sketch program that will allow us to read pixel coordinates. You need first to get the dimension of the picture, by right-clicking on the picture and then choose properties and then details.

For my project, the image size is 1844 x 1600.

The needle design is a triangle ABC, with this little sketch program, we will get the coordinate of the points ABC and the center O. we will need those coordinates to design our virtual needle.