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Arduino Uno Com Port - changes Com Port 3 to Com Port 5
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Please be positive and constructive with your questions and comments.

Arduino Uno Com Port - changes Com Port 3 to Com Port 5

by JHRrec on Mon Nov 20, 2017 1:55 pm

Purchased 1st Arduino Uno R3 around last February or so. WORKED GREAT!
Purchased 2nd Arduino Uno R3 a few months later. It BLINKED properly when plugged in, but changed com port 3 to com port 2 when I loaded blink program. It was useless!
I was so confident products from Adafruit would work, I did not even try it for about 60 days after purchase. Thought it was a
fluke. I thought it was too late to get support from Adafruit.

Purchased 3rd Arduino Uno R3 on Nov. 7, 2017. Same problem as 2nd Arduino.

Details:

Plug 1st board in, uploaded Blink, worked fine. Can run many programs just fine. Still works fine.

Plug 3rd board, hit upload, and get error message:
Problem uploading to board. See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.
avrdude: ser_open() can't open device "//.com3: The system cannot find the file specified.

When I click TOOLS > PORT it shows: " Com2 (Arduino/Geniuno Uno)

I've tried changing port back to 3, using Device Manager, etc, and nothing works.

I tried to Burn Bootloader on 2nd unit, and had problems.

What is different? Why does the 1st Arduino work, 2nd and 3rd Arduinos don't?

JHRrec
 
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Joined: Fri Nov 10, 2017 6:46 pm

Re: Arduino Uno Com Port - changes Com Port 3 to Com Port 5

by adafruit_support_bill on Mon Nov 20, 2017 2:09 pm

The UNO does not set the com port number. That is assigned by your computer. It is not unusual for Windows to assign different COM port numbers to different USB/Serial devices like Arduinos. If it is showing up as COM2 in device manager, then you should select COM2 in the IDE.

adafruit_support_bill
 
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Joined: Sat Feb 07, 2009 10:11 am

Re: Arduino Uno Com Port - changes Com Port 3 to Com Port 5

by clubcard on Wed Feb 14, 2018 8:25 am

My second (first unit was replaced)) Uno M0 Pro is doing the same thing. Yes, it isn't the COM port, it just doesn't work. Cannot burn bootloader or download data:

I2 Arduino Uno M0 Pro fails.

by clubcard on Wed Feb 14, 2018 8:12 am

Hi,
Now on my second Arduino Uno Pro and it fails to allow a bootloader to be burnt:

This report would have more information with
"Show verbose output during compilation"
enabled in File > Preferences.
Arduino: 1.0.6 (Windows NT (unknown)), Board: "Arduino Uno"
C:\Program Files (x86)\Arduino\hardware/tools/avr/bin/avrdude -CC:\Program Files (x86)\Arduino\hardware/tools/avr/etc/avrdude.conf -v -v -v -v -patmega328p -cstk500v1 -P\\.\COM5 -e -Ulock:w:0x3F:m -Uefuse:w:0x05:m -Uhfuse:w:0xde:m -Ulfuse:w:0xff:m


avrdude: Version 5.11, compiled on Sep 2 2011 at 19:38:36
Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
Copyright (c) 2007-2009 Joerg Wunsch

System wide configuration file is "C:\Program Files (x86)\Arduino\hardware/tools/avr/etc/avrdude.conf"

Using Port : \\.\COM5
Using Programmer : stk500v1
avrdude: Send: 0 [30] [20]
avrdude: Send: 0 [30] [20]
avrdude: Send: 0 [30] [20]
avrdude: Recv:
avrdude: stk500_getsync(): not in sync: resp=0x00

avrdude done. Thank you.



And to download example/basic/blink:


This report would have more information with
"Show verbose output during compilation"
enabled in File > Preferences.
Arduino: 1.0.6 (Windows NT (unknown)), Board: "Arduino Uno"
C:\Program Files (x86)\Arduino\hardware/tools/avr/bin/avrdude -CC:\Program Files (x86)\Arduino\hardware/tools/avr/etc/avrdude.conf -v -v -v -v -patmega328p -cstk500v1 -P\\.\COM5 -e -Ulock:w:0x3F:m -Uefuse:w:0x05:m -Uhfuse:w:0xde:m -Ulfuse:w:0xff:m


avrdude: Version 5.11, compiled on Sep 2 2011 at 19:38:36
Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
Copyright (c) 2007-2009 Joerg Wunsch

System wide configuration file is "C:\Program Files (x86)\Arduino\hardware/tools/avr/etc/avrdude.conf"

Using Port : \\.\COM5
Using Programmer : stk500v1
avrdude: Send: 0 [30] [20]
avrdude: Send: 0 [30] [20]
avrdude: Send: 0 [30] [20]
avrdude: Recv:
avrdude: stk500_getsync(): not in sync: resp=0x00

avrdude done. Thank you.


Now, I've tried it with 3 cables and other devices in the same USB ports I've used all work fine. I even went back to 1.0.6 and it just fails with a less descriptive explanation. The PC detects the USB device being hot-plugged in and out but it doesn't recognize it as a device. The IDE says it's programming an Uno ISP but I also tried AVR ISP.


The odd thing - the very first download worked. Blink.... blinked. Then after a few seconds it stopped and the PC threw out the 'not in sync' error. Sorry to bother you but I'm not quite sure how to proceed. Different bootloader? If so, which?
clubcard
 
Posts: 22
Joined: Sun Dec 29, 2013 10:28 am

Re: Arduino Uno Com Port - changes Com Port 3 to Com Port 5

by adafruit_support_bill on Wed Feb 14, 2018 8:37 am

@clubcard - This post is off-topic for this thread - and a double post as well. Please stick to one thread per question: viewtopic.php?f=25&t=131066&p=651362#p651362

adafruit_support_bill
 
Posts: 68652
Joined: Sat Feb 07, 2009 10:11 am

Please be positive and constructive with your questions and comments.