'serial port already in use'...

Development Tools IDE 1.x
1

Hi

I just get a package with my first arduino leonardo.
Im using mac os x 10.9.

And i have a problem, ALMOST every time when Iam trying to upload a program to arduino i see:

processing.app.SerialException: Serial port '/dev/tty.usbmodemfd121' already in use. Try quitting any programs that may be using it.

I was trying to find a solution of my problem in internet and I've done this:
http://forum.arduino.cc/index.php?topic=198539.0
and I made /var/lock and changed its chmod to 777

I wrote that i have this problem ALMOST everytime becouse at first i menaged to upload first blinking program, but right now I cant do anything.

Every solutions that I found are those two - I have no idea what should I do.

Please help me!

EDIT:
I tried to upload program a few times in a row, and it works about once every 4-5 times... what can I do with this? please help!

PS: sorry for my english, I hope you understand everything

2

any ideas? please!

3

I have the same problem with OSX and my Micro(same layout as Leonardo) but all of my sketches upload despite the error. Try shortening the delays in your blink sketch and see if the led pulses faster despite the error message.

4

Yor English sounds great

5

I am able to upload program to arduino, but it works only sometimes, i have to try at least 4-5 times before it works. I sent an email to shop I've bought the board from and they told me to send arduino back to them, and they will check if its OK for shure.

I tried to work on windows for a while, but I cant even install drivers properly there, so probably there is something wrong with the board.

6

Do the first step and see what else is using the serial port when it is claimed to be "in use."

OSX doesn't report it is in use, unless something claims it.

7

James C4S, thank you a lot of! /var/lock trick is working for me.