Keyboard controlled servo

Projects General Guidance
1

Hello,

I got a little project where i'm trying to control a servo with a key press from the keyboard, and i made it work (partially at least),
if i press the left arrow it goes to the left and if i press the right arrow it goes to the right ,very basic stuff, but now i want it to stop when i release the key and not go all the way and i cant seem to find the right method , i dont know if its something in the processing code or in the arduino one. I'm using and arduino Leonardo board and an 6001HB servo.
Here is the processing code:

 import processing.serial.*;
 color fillVal = color(0,0,0); // set variable 'fillVal'
 Serial port;
 
 void setup() {
 size(100, 100);
 println("Available serial ports:");
 println(Serial.list());
 port = new Serial(this, Serial.list()[1], 9600);  
 }
 
 void draw() {
   background(0,0,0);
   if (keyPressed == true) { // if key is pressed
   fill(fillVal);
   ellipse(50, 50, 50, 50); 
   }
   else {
    keyReleased(); 
   }
 }

void keyPressed() {
     if (key == CODED) {
       if (keyCode == LEFT) {
         fillVal = color(255,255,255); 
       } 
       else if (keyCode == RIGHT) {
         fillVal = color(0,255,150);
       }
     } else {
    fillVal = 0;
  }
  port.write(keyCode);
  if (keyPressed == false) {
    port.write('0');
  }
}

void keyReleased() {
  port.write('0'); 
}

And the Arduino one:

#include <Servo.h> 

Servo servo1,
 
int pos = 0;   

const unsigned int BAUD_RATE = 9600;

char key = 0;

void setup() {
  servo1.attach(2);
  
   Serial.begin(BAUD_RATE);
}

void loop() {
  if (Serial.available()) {
     key = Serial.read();
     if (key == byte(37)) 
     { //left
       for(pos = 0; pos < 180; pos += 1)
         {                               
            servo1.write(pos);            
            delay(15);                        
         }
     } 
     else if (key == byte(39)) 
     { // right
       for(pos = 180; pos >=1; pos -= 1)
         {                               
            servo1.write(pos);           
            delay(15);                     
         }
     }
        
   }
}
2

could you not do something like this?

if (Serial.available()) {
     key = Serial.read();
     if (key == byte(37)) 
     { //left
       pos = ++pos;
         {                               
            servo1.write(pos);            
            delay(15);                        
         }

I guess that each time you press the left button it would move it one more step to the left,
I think that the serial input would need to be sent by pressing enter each time, so I dont know if you can simply hold a ky down and keep the servo moving. Another thing you could of course do would be to make it keep moving until a stop key was pressed.

3

The system on the PC generates keyDown and keyUp events. If you write your own PC program you could detect them and use them to send ON and OFF messages to the Arduino.

...R

4

The trick is to send a code on key press, which you are doing, and another on key release which you are not.

Then on the arduino side use the key presses just to toggle a logic variable. Use that variable outside the recieve serial section to controll if you increment and move your servo.

5

The trick is to send a code on key press, which you are doing, and another on key release which you are not.

Then on the arduino side use the key presses just to toggle a logic variable. Use that variable outside the recieve serial section to controll if you increment and move your servo.

+1

6

raschemmel:

The trick is to send a code on key press, which you are doing, and another on key release which you are not.

+1

I got there first !!!!!!!!

...R

7

The system on the PC generates keyDown and keyUp events. If you write your own PC program you could detect them and use them to send ON and OFF messages to the Arduino.

The trick is to send a code on key press, which you are doing, and another on key release which you are not.

Then on the arduino side use the key presses just to toggle a logic variable. Use that variable outside the recieve serial section to controll if you increment and move your servo.

So you did.
+1