IDE not recognising serial port

Hoping for advice on an issue I have just encountered.

I am trying to get my LED strips to light up. They are WS2812B 5050 RGB.

I am running the AdaFruit_NeoPixel library.

Running Mac OSX 10.11.6.

I am just trying to compile the example code included with the library.

The code verifies without an issue, but when I try and upload I get the following message.

avrdude: ser_open(): can't open device "/dev/cu.usbmodem1411": No such file or directory
Problem uploading to board.  See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.

It also appears that I can no longer select the correct serial port from my list of ports.

I was able to previously fix this through just restarting my computer, but this no longer seems to be working. When I first downloaded the IDE, I was able to select the port without an issue.

Any advice most appreciated.

Thanks,

m

Hi Marty, this is one of the most frustrating and difficult problems with using Arduinos. When they work well, they can easily connect to a large variety of computers and operating systems. But when they misbehave, it can be very ... well you know. Bad.

There is no set and easy solution. Once you have eliminated all the fixes in the list the error message points you to, it's time to start improvising.

The fix I have used several times - always with eventual success - is to open a simple sketch, such as Blink.ino. Compile the code, then click the upload button in the IDE, and immediately press the reset button on the board. If it doesn't upload, do it again. And again and again and ...

Eventually (hopefully) it will take and the sketch will upload. After that, the board should be fixed. One time it took me 13 tries before the sketch uploaded. Only in one case was I unable to get the problem to resolve (littleBits module, which is a Leonardo clone with limited pins broken out.)

Good luck!

ps, what board are you using? I have used this recovery method with Arduino Micro, littleBits Arduino module and Osepp Uno R3 clones. I don't know about others. I have never had a problem with official Arduino Unos and Pro Minis, Adafruit Trinkets and Pro Trinkets, DFRobot Beetles and Girl Boards, or naked Tiny85s, Tiny84s, and 328s. I suspect that boards that use the 32u4 microprocessor may be more susceptible to the problem, but that may just be my limited samples.

Your Arduino's USB-to-Serial chip is not showing up as a serial port. You may need to install (or re-install) a driver. What is the label on the chip near the USB port? Common choices are:
ATMEL MEGA16U2 (Official Arduino and some clones)
FTDI FT232RL (Most older clones)
WCH CH340G (Most newer clones)

Check for updates to the drivers.

Mac OS made some changes to the USB driver model in recent releases that require corresponding updates to the drivers. Apple don't seem to do much compatibility testing with third party drivers, so it's up to you to keep things up to date.

Thanks everyone - really appreciate it.

I'm running an Uno.

I've found another option online, which I was wondering what people thought of installing a signed USB driver kernel extension? I'm happy to try, but nervous that I might mess something up with my computer - not sure what kernels are and why I might need an extension!

CHeers,

m

Just make sure it is not your USB port first. Disconnect all hardware from the Arduino, plug it in and try and upload a sketch.
What could be happening is that the LED strip is taking too much current and shutting down the USB port. With luck it has not permanently damaged the port, reboot your Mac and try again.

You must always use an external 5V supply for those strips if you have anything over 8 LEDs in them. They can power up in the on state you know.

Thanks Grumpy_Mike.

Grumpy_Mike:
Just make sure it is not your USB port first. Disconnect all hardware from the Arduino, plug it in and try and upload a sketch.

Which USB port did you mean? The USB on my Mac works fine.

In terms of uploading a sketch to my Arduino - the error that I am receiving prevents me from doing that.

Grumpy_Mike:
What could be happening is that the LED strip is taking too much current and shutting down the USB port. With luck it has not permanently damaged the port, reboot your Mac and try again.

Thanks - yes, I hope my port is not damaged!

Grumpy_Mike:
You must always use an external 5V supply for those strips if you have anything over 8 LEDs in them. They can power up in the on state you know.

Thanks - I am using a 5V supply for the strips.

Maybe you don't get what @Grumpy_Mike said; or maybe I don't get what you're saying :wink: Disconnect everything from the Uno, connect bare Uno to Mac and next try to upload e.g. the blink sketch.

Does that work?

And that is how far my knowledge of Macs goes.

Thanks everyone.

I have just powered everything up again after a week's absence, and it all appears to be working as normal. Go figure.

I've uploaded a sample sketch from the Adafruit_NeoPixel library, and it is working fine. I'm going to just leave it alone for now, as the current pattern will work reasonably well for the project I am working on.

Will try some of the fixes here (and those that I have found elsewhere - like here) once I have finished this current project.

Thanks again! :slight_smile:

Hi,
In your sketch that you previously had loaded did you use pins 0 and 1 for any I/O?

Tom... :slight_smile:

Thanks Tom.

No, I was only using pin 6.