ALL CODING RELATED INFORMATIONS OF THIS PROJECT

Below are some coding notes and considerations.
If you would like to look at the whole project files and more, you can visit our GitHub organization and our main project repository where everything related to Remote Arm project (coding related and more) is saved and documented.
I'd suggest to also take a look at all the tests I made before starting with the arm project directly, just to get known with Arduino better; trust me some of them were really cool to look at!

Splitting the work

As we said before, we divided the coding tasks into 2:

The Physical coding team would have worked on the physical base (like fingers movements), the Connection / Cloud coding team would have worked on figuring out the best way to connect remotely the two Arduinos and also code it.

As the physical base group proceeded, the connection team instead thought at first to buy a server and a domain to make the two boards communicate, it wasn't hard to code either but issues like "what would happen if you stopped paying yearly for the server" popped up: if we wanted something to be working forever we had to find another way.
While searching online we found out about Arduino Cloud and it being free and compatible with our R4 boards.
After the connection ran some tests to understand how it worked, they immediately understood that it was the best option.

How it developed

As the physical base group started using the servos and flex libraries to complete it whole, the connection team made two Arduino Could "Things"; the Glove Thing and the Arm Thing and linked the two arduinos to them, using at first a single sycnhronized variable that was a string containing all the needed finger and body parts movement degrees splitted by a comma through a specific split code: at first they thought this would make it faster to send since they were less Bits, the arm would split and get the right values out of the string.
Although after a while they realized that it was annoying understanding on which position of the string were the right degree values of each arm part and that using multiple integrer values wouldn't made the project lag at all and so they went for that way.

How it ended

Once every group finished their coding part, NexIsDumb started merging everything together and separating the right way the Arm and Glove code and optimize it too a little bit. With Matte549's help they also started to find the right finger max and min values for making it work best.
The final big showcase and test of the project was made at NexIsDumb's finals: during the last exam he started moving with Matte549's help the arm perfectly fine through the glove and all professors were completely amazed!
Unfortunately we couldn't make it in time to add the palm, elbow and wrist, but they aren't hard to add since the code for them is already there.

More coding notes

For getting the flex sensors and potentiometers values, the glove's code uses an analogRead function to get from the desired pin a value between 0 and 1023. To make sure this number was translated into integrer angles, we've used a map function setting specific min and max of the angles (that the program would have used based on analogRead's raw number) based on how we've placed the servomotors in the arm, this took bunch of tries as you have to look on their position and rotation.
Here's an example:

indexDeg = map(analogRead(indexPin), 0, 1023, 0, 180);  // From 0 to 1023, the raw number will be translated to: 0 to 180

Also during revisions, NexIsDumb felt better with using constants on some specific stuff like pin positions, for example:

const int potPinPollice = A1;  // Analogic thumb A1 pin connected to the potentiometer

Before we deleted the splitting string method, this was the split string function made by NexIsDumb (it was probably not perfect since it used dynamic memory, but was still cool to see it in action, probably using char* (aka C strings) would have been better):

const int MAX_RECEIVED_DEGREES = 5;

/*
  Splits a string with commas into an array of ints, for example "125,65,34" => [125,65,34]
*/
void getDegreesFromString(int degs[MAX_RECEIVED_DEGREES], String infos, char delim = ',') {
  int t = 0, r = 0, i;
  for (i = 0; i < infos.length() + 1 && t < MAX_RECEIVED_DEGREES; i++) if (infos[i] == delim || i == infos.length()) {
    if (i - r > 1) {
      degs[t] = infos.substring(r, i).toInt();
      t++;
    }
    r = i + 1;
  }
}

A little consideration

This demonstrates that even something so easy to code can become something really cool, perfect ending and perfect prototype for a school project, HAH!
- Nex