Hello, I've been playing around with an Arduino Uno for a few days now, and haven't had any issues uploading/compiling code. Today, I got this error message when I tried to compile:
"avrdude: ser_open(): can't open device "/dev/cu.usbmodem143101": No such file or directory"
This is a screenshot from a Youtube video so the numbers aren't the same, but I used to see this (top option is what I want), now only the bottom 2 options are available:
MacBook Pro 2019, Sonoma 14.4 (USB C ports, so I use a dongle; this might be important for later)
Arduino Uno
Software:
Arduino IDE 2.3.3
Things I've tried/potentially relevant info:
Resetting the Uno and uploading a simple Blink sketch - the IDE briefly registered the USB connection, long enough to push the Blink program and then lost it again
When I connect the UNO via USB, the green "on" light and orange blinking LED both are on
Checking System Information > Hardware > USB - I think because I'm using a dongle that my laptop is registering the dongle not the Uno specifically
Arduino AVR Boards is the only thing installed in Board Manager
When I first plugged the Uno in, I didn't get a "new network device" popup for Network Preferences, which is what many sources say should happen -- the USB connection simply popped up in the IDE ports options and I chose it
Can anyone please suggest something else I can try or check? Thank you! I am happy to provide more info
If you reset the Uno again now, does this "IDE briefly registered the USB connection" behavior occur?
I've never observed this behavior on my macOS machine. Maybe those sources you found were specific to certain boards that have Wi-Fi connectivity (and so not relevant for the Uno R3)?
I just tried resetting again by unplugging USB, holding down reset, plugging USB back in, and uploading a sketch. I don't know why it's suddenly working again after like 3 hours. The numbers have changed so now it's 143301 instead of 143101, does that mean something? I'm nervous I'll encounter this again -- do you know what causes this to happen?
Huh, that's interesting. This WSU website (chipKIT - MacOSX) and a book I was looking at both mentioned it but I was able to get by without it.
With some Arduino boards, it is possible for your sketch program to interfere with the functioning of the USB stack that produces a USB CDC serial port. In that case, resetting the board is a way of restoring the serial port so an upload can be accomplished.
However, the UNO R3 is not one of those boards. The UNO R3 has a dedicated USB chip which can not be affected by the sketch program. So your observation that the port of this board is restored by a reset is more unexpected. My hypothesis would be that the fault is caused by some external circuitry you have connected to the UNO R3 board. In this hypothesis, the fault occurs when the sketch program acts on that external circuitry (e.g., activating an external component that draws more current from the board than it can provide), so by resetting the board you temporarily defer the fault. If you have any external circuitry/modules/shields connected to the UNO board, you should carefully examine it. If you don't have any external circuitry then do a careful check for any conductive debris on the board that might be causing a short. If the bottom of the board is not insulated, also check for conductive debris on the surface the board is sitting on, or if the surface is metal place a non-conductive covering between the board and the surface.
I did have external things attached last night, and when I ran my program I forgot to attach a battery to one portion (not the Arduino though) so maybe that is what caused the issues (I'll post about my project issues in the Projects category). Only today did I remove everything to try to troubleshoot what wasn't working. Thanks for your help!
