cannot invoke write(char) on the primitive type char

and its highlighting the serial.write( 'e');

1.    switch (key) {
2.       case 'e':
3.       case 'E':
4.       serial = 'e';
5.         serial.write( serial );
6.       break;

Just tried what you said and still came up with the same error.

amnon.owed:

I tried your code out it almost works but keeps crashing. But just looking at it, I have to be able to individually control each key. so doing a string won't work because i might use eeElqeEiiiiel. I have to have flexibility. pretty much what I want is to assign a letter to a pin.

Now my old code worked which was the following:

2. import processing.serial.*; //Import the serial library into your sketch
3. 
   
4. import cc.arduino.*;        //Import the Arduino-Firmata library into your sketch
5. 
   
6. Arduino arduino;      //Create an instance of Arduino named arduino (can be any name) 
7. 
   
8. int ledPin;
9. int ledPinHIGH = 53;  //Create a varibale ledPin and assigns a value of 13 to it.
10. int ledPinHIGH1= 23;
11. int Leftmotorforward= 2;
12. int Leftmotorreverse= 3;
13. int Rightmotorforward= 4;
14. int Rightmotorreverse= 5;
15. int Rollerarmenable= 34;
16. int Rollerarmmotor= 35;
17. int Rollerarmforward= 43;
18. int Rollerarmbackwards= 42;
19. 
    
20. void setup() {
21.   size(200, 200);    
22.   arduino = new Arduino(this, Arduino.list()[0], 57600); //defines arduino our board and sets the communication rate
23.   arduino.pinMode(ledPin, Arduino.OUTPUT);
24.   }
25. 
    
26. void draw()
27. {
28.   arduino.digitalWrite(ledPinHIGH, Arduino.HIGH);
29.   arduino.digitalWrite(ledPinHIGH1, Arduino.HIGH);
30. };
31. 
    
32. void keyPressed() {
33.     print(key);
34.     switch (key) {
35.       case 'e':
36.       case 'E':
37.       arduino.digitalWrite(Leftmotorforward, Arduino.HIGH);
38.       break;
39.       case 'd':
40.       case 'D':
41.       arduino.digitalWrite(Leftmotorreverse, Arduino.HIGH);
42.       break;
43.       case 'i':
44.       case 'I':
45.       arduino.digitalWrite(Rightmotorforward, Arduino.HIGH);
46.       break;
47.       case 'k':
48.       case 'K':
49.       arduino.digitalWrite(Rightmotorreverse, Arduino.HIGH);
50.       break;
51.       case 'f':
52.       case 'F':
53.       arduino.digitalWrite(Rollerarmenable, Arduino.HIGH);
54.       arduino.digitalWrite(Rollerarmmotor, Arduino.LOW);
55.       break;
56.       case 'r':
57.       case 'R':
58.       arduino.digitalWrite(Rollerarmenable, Arduino.HIGH);
59.       arduino.digitalWrite(Rollerarmmotor, Arduino.HIGH);
60.       break;
61.       case 'u':
62.       case 'U':
63.       arduino.digitalWrite(Rollerarmforward, Arduino.HIGH);
64.       break;
65.       case 'j':
66.       case 'J':
67.       arduino.digitalWrite(Rollerarmbackwards, Arduino.HIGH);
68.       break;
69.     }
70.  
71.   };
72. 
    
73. void keyReleased() {
74.     switch (key) {
75.       case 'e':
76.       case 'E':
77.       arduino.digitalWrite(Leftmotorforward, Arduino.LOW);
78.       break;
79.       case 'd':
80.       case 'D':
81.       arduino.digitalWrite(Leftmotorreverse, Arduino.LOW);
82.       break;
83.       case 'i':
84.       case 'I':
85.       arduino.digitalWrite(Rightmotorforward, Arduino.LOW);
86.       break;
87.       case 'k':
88.       case 'K':
89.       arduino.digitalWrite(Rightmotorreverse, Arduino.LOW);
90.       break;
91.       case 'f':
92.       case 'F':
93.       arduino.digitalWrite(Rollerarmenable, Arduino.LOW);
94.       arduino.digitalWrite(Rollerarmmotor, Arduino.LOW);
95.       break;
96.       case 'r':
97.       case 'R':
98.       arduino.digitalWrite(Rollerarmenable, Arduino.LOW);
99.       arduino.digitalWrite(Rollerarmmotor, Arduino.LOW);
100.       break;
101.       case 'u':
102.       case 'U':
103.       arduino.digitalWrite(Rollerarmforward, Arduino.LOW);
104.       break;
105.       case 'j':
106.       case 'J':
107.       arduino.digitalWrite(Rollerarmbackwards, Arduino.LOW);
108.       break;
109.     }
110. };

This code worked for me, but I had to use firmata for arduino and thats not really what I should be using for arduino. Plus when I was using my xbee's to wirelessly communicate, some times it wouldn't receive a command such as when I let go of a button (keyReleased), so there was a coding error somewhere. This code makes sense, but if there is anyway to improve on it, then I will. PLUS I am unable to use analog control since something with firmata doesn't allow it to use it.