Fix Example 4 for the Electronics Tutorial

[REAS]

https://processing.org/tutorials/electronics/

Requires an Arduino and Servo motor

[JanoVel]

It's not working for me, the servo remains in the same position.
I'm using Processing 3.2.3 and Arduino 1.6.13

[REAS]

I don't have an electronics setup right now to test this. It would be ideal if someone could make a pull request for it, or to modify the code for the current Arduino way of doing things.

[REAS]

And, thank you @JanoVel for the confirmation. I just changed the title of the Issue to reflect your confirmation.

[JanoVel]

I just checked the code and there are some issues that I found in both the Arduino and Processing Sketches.

Arduino side

• The sketch defines the control I/O pin as 4, but it is not a PWM pin, which is needed for servo control
• The wiring diagram shows the control wire of the servo connected to I/O pin 0, which besides not being the same one as in the sketch is also not PWM
• The sketch is reading the value sent from Processing as if it were an integer, when in fact it is a series of characters (the sketch must translate this into an integer)

Processing side

• The sketch assumes the serial port is COM1, which is not the case on my setup (Debian). Perhaps it would be convenient to let the user choose the appropriate port.

I have already modified the Arduino sketch to work, I'm now working on modifying the Processing sketch to allow the user choose the serial port. I'll make a pull request when I'm done (perhaps tomorrow or during the weekend).

As for the wiring diagram, I can modify the image to correct the error while preserving the style of the document.

[JanoVel]

I was wrong about the last point of the Arduino sketch, only the output pin needs to be changed.