Comments on: Arduino-Python 4-Axis Servo Control

By: Brian

Brian — Tue, 09 Mar 2010 12:21:47 +0000

@John: Thanks for stopping by. Ethernet/ZigBee/WiFi would be awesome ways to take this project to the next level. I think it would be really cool to use this as a basis for a LAN robot or RC vehicle of some kind.

I haven't played around with that stuff at all, but you'd have to change all the communication stuff from serial to HTTP. I'd start by checking out the Arduino Ethernet library.You'll also have to change servo.py significantly in order to talk to Arduino.

I'd probably head over to the Adafruit forums and see what others are saying. They'll have more expertise over there!

By: John

John — Tue, 09 Mar 2010 04:13:40 +0000

Hey Brian, I'm new to the arduino world but this 4 servo project will be a great start for me. One question. What if I wanted to use an ethernet shield rather than doing this over serial. Any thoughts as to where I might look for ideas?

Cheers

John

By: Brian

Brian — Sun, 21 Feb 2010 20:23:10 +0000

@Lucky: Thanks for your comments. I'm not sure what is going on with your setup, but if I were you, I would uncomment all the lines from multijoystick.py which read:

#output(str, e.dict['joy'])

This will print out your joystick positions in Windows Command Prompt (terminal), so you can see what it's sending to the Arduino.

Also, you might try experimenting with the minPulse and maxPulse variables in the MultipleSerialServoControl sketch:

// Common servo setup values
int minPulse = 600;   // minimum servo position, us (microseconds)
int maxPulse = 2400;  // maximum servo position, us

Good luck!

By: Lucky

Lucky — Sun, 21 Feb 2010 20:05:22 +0000

Hi! How to modify program to change servo speed? I have a problem that in zero joystick position servo still rotates till the end in one direction. What it can be? it is not like stop rotating but continue.

By: Lucky

Lucky — Tue, 16 Feb 2010 19:08:20 +0000

Brian! you are genius! ;-) I just want to remind for beginners who is using Windows XP: I had problems before because of using Python 2.6. If something does not work like pygame is not running - remember in Windows XP: you install Python 2.5. (not older)! then you install pyserial-2.5-rc2.win32, pygame-1.9.1.win32-py2.5, and run in parralel arduino 0018. After this joystick is detected automatically and you can play!

1 joystick(s) detected.
Joystick 0: Saitek Cyborg X
Depress trigger (button 0) to quit.

By: Dude

Dude — Thu, 11 Feb 2010 19:28:41 +0000

@Brian: I'm using XP so yes, ran as admin. I don't really think, XP has any permission tools going on when it comes to that.

I'm really lost here. It works just fine on my macbook. Weird, really.

By: Brian

Brian — Thu, 11 Feb 2010 16:50:12 +0000

@Dude: To me it looks like a permission error. When you installed Python (and/or serialwin32.py), did you do it as the Administrator?

By: Dude

Dude — Wed, 10 Feb 2010 22:25:28 +0000

This looks great! Tho i have problems with my PC:

Traceback (most recent call last): File "C:\Python26\servo.py", line 20, in ser = serial.Serial(usbport, 9600, timeout=1) File "C:\Python26\lib\site-packages\serial\serialwin32.py", line 30, in init SerialBase.init(self, *args, **kwargs) File "C:\Python26\lib\site-packages\serial\serialutil.py", line 201, in init self.open() File "C:\Python26\lib\site-packages\serial\serialwin32.py", line 56, in open raise SerialException("could not open port %s: %s" % (self.portstr, ctypes.WinError())) SerialException: could not open port COM3: [Error 5] Access is denied.

As far as i can tell the error means that COM3 port is in use by other program, but the thing is, its not. I don't know whats going on...

The whole thing works just fine with my mac on the other hand. Any ideas?

By: sanjay srkanth

sanjay srkanth — Wed, 10 Feb 2010 19:57:05 +0000

@brain Thanks a lot man

By: Brian

Brian — Tue, 09 Feb 2010 16:12:39 +0000

@sanjay: Do you have servo.py installed in the same directory as multijoystick.py?