Serial Port Not Found During Lesson 4

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eggwardo
 
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Serial Port Not Found During Lesson 4

Post by eggwardo »

I just got an UNO. I got through the first tutorials just fine. (Other than Linux related hiccups getting started. (Ubuntu) I've worked with electronics before (LED's, 555's capacitors) so the LED stuff was simple and very much fun.

I got to the part of lesson 4 where you make the "hello world" keep repeating. I put it onto the UNO and now i can't get anything to work right. The TX light is on constantly so i think the sketch is on my uno but somehow not right. I've been trying to load a different sketch onto it but it wont work. Sometimes it says "Serial Port Already In Use" but usually the serial port doesn't even show up as an option.

I really think if there's a way to "manually" delete a sketch off the UNO that would work for me but haven't found anything suggesting i can do that.

Does anyone have any suggestions on how to fix this?

Thanks in advance

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adafruit_support_bill
 
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Re: Serial Port Not Found During Lesson 4

Post by adafruit_support_bill »

A couple things to try:
Press the reset button on the board, then try to download again.
If that fails, exit and restart the Arduino software. (If there are multiple windows open, be sure to close all of them).

eggwardo
 
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Re: Serial Port Not Found During Lesson 4

Post by eggwardo »

I've tried both of those. Even restarted the computer.
Hitting reset then downloading was the same fail. It seems like it's so busy sending "hello world" it can't do anything else.
Thanks

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adafruit_support_bill
 
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Re: Serial Port Not Found During Lesson 4

Post by adafruit_support_bill »

Is it actually sending "Hello World"? Do you see this in the serial monitor?
The reset button should stop the running program and give the boot-loader a time-window to load a new one. If you press reset, is there any change in the LEDs?

eggwardo
 
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Re: Serial Port Not Found During Lesson 4

Post by eggwardo »

Whenever I try to open the serial window I get an error. Not at my computer right now but I believe it says something about not finding the serial port.
When I hit the reset button the other led blinks very briefly and then it's right back to the tx light being on.
Ill try the reset thing again tonite but when I was trying it before it kept losing contact with the port. I'm also going to try a different cable but any other ideas will be appreciated

eggwardo
 
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Joined: Mon Nov 15, 2010 9:25 pm

Re: Serial Port Not Found During Lesson 4

Post by eggwardo »

Figured it out from another forum. And my suspicion was correct. Something about one chip not being able to start because the other one was already transmitting. Looks like a lot of people with Ubuntu and Uno get this problem occasionally.

Anyway to fix it. Hold the reset button on the UNO as you plug in the USB cable. Then just install a sketch you know works.

If you're doing this with Lesson 4 and you have the problem where i did (when you loop "Hello World!") then just skip to the very next step and add the delay in. Then it will work.

thanks for your help arduwino :D

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adafruit_support_bill
 
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Re: Serial Port Not Found During Lesson 4

Post by adafruit_support_bill »

Thanks for the update. I haven't seen this one before, but it's good to know there is a workaround. :D

McBain
 
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Re: Serial Port Not Found During Lesson 4

Post by McBain »

Since the last post was made on here, new firmware was released for the Uno which purportedly allows Ubuntu users to dispense with these inconsistent ad hoc workarounds (holding reset button while plugging in, etc.). I hope this is helpful to other Ubuntu/Uno users who have struggled, as I have, with an IDE that keeps freezing up and sketches that won't upload. See post #34 below for the links to download the firmware:

http://www.arduino.cc/cgi-bin/yabb2/YaB ... 088093/all

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