Can't upload any sketch using visual code (Errno 16) Resource busy on Mac OS

samgozman · January 24, 2019, 9:52pm

I just cant upload any sketch (VS code, Mac OS). I’ve tried normal upload and verbose, changing ports, reboots, rebuilds, terminal command lsof | grep etc… I still can upload sketches using Arduino IDE, so I don’t know whats the problem with platformio…
Thank you kindly for your answers!

> Executing task in folder geek-watches-display: platformio run --target upload <

Processing nanoatmega328 (platform: atmelavr; board: nanoatmega328; framework: arduino)
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Verbose mode can be enabled via `-v, --verbose` option
CONFIGURATION: https://docs.platformio.org/page/boards/atmelavr/nanoatmega328.html
PLATFORM: Atmel AVR > Arduino Nano ATmega328
HARDWARE: ATMEGA328P 16MHz 2KB RAM (30KB Flash)
Library Dependency Finder -> http://bit.ly/configure-pio-ldf
LDF MODES: FINDER(chain) COMPATIBILITY(soft)
Collected 25 compatible libraries
Scanning dependencies...
Dependency Graph
|-- <ShiftDisplay> 3.6.1
Checking size .pioenvs/nanoatmega328/firmware.elf
Memory Usage -> http://bit.ly/pio-memory-usage
DATA:    [=         ]   6.7% (used 137 bytes from 2048 bytes)
PROGRAM: [=         ]   7.5% (used 2310 bytes from 30720 bytes)
Configuring upload protocol...
AVAILABLE: arduino
CURRENT: upload_protocol = arduino
Looking for upload port...
Auto-detected: /dev/cu.usbserial-1420
*** [upload] could not open port /dev/cu.usbserial-1420: [Errno 16] Resource busy: '/dev/cu.usbserial-1420'
=============================================================================================== [ERROR] Took 0.82 seconds ===============================================================================================
The terminal process terminated with exit code: 1

Terminal will be reused by tasks, press any key to close it.

maxgerhardt · January 25, 2019, 5:19pm

Do you have the serial monitor open when trying to upload the sketch? You must close the serial monitor then.

Does re-plugging the Nano help?

samgozman · January 25, 2019, 10:11pm

Thanks for reply! Of course I didn’t have the serial monitor open. And I tried to change usb ports, nothing helped yet

maxgerhardt · January 25, 2019, 11:07pm

What does lsof /dev/cu.usbserial-1420 output before you try to upload? Is this also the same serial port you’re using with Arduino IDE? Does closing the Arduino IDE before trying to upload make a difference?

fenbranklin · August 16, 2019, 8:07pm

Guessing perhaps the auto-port detection doesn’t quite work for macOs. Edit your platformio.ini and add:
upload_port = /dev/cu.wchusbserial1420

While you’re there, you might also verify that you have the correct upload speed. For my ESP8266 board I had to use 115,200 baud, as the default was causing a timeout error.
upload_speed = 115200

knightofnih · August 21, 2020, 2:05pm

Upgraded from MacOS 10.13: High Sierra to MacOS 10.14 and encountered this error. Specifying the upload port in my platform.io fixed the problem. Thanks @fenbranklin!

fenbranklin · August 21, 2020, 2:22pm

Glad to hear it worked for you! Happy to say that since I fixed this issue a year ago, my Arduino project has been sitting in a box outside, reporting in every hour through all four seasons!

programonauta · April 14, 2021, 10:51pm

Hi @samgozman

Did you get to solve your problem?

I have the same problem with a ESP32

--- Available filters and text transformations: colorize, debug, default, direct, esp32_exception_decoder, hexlify, log2file, nocontrol, printable, send_on_enter, time
--- More details at http://bit.ly/pio-monitor-filters
could not open port '/dev/cu.SLAB_USBtoUART': [Errno 16] could not open port /dev/cu.SLAB_USBtoUART: [Errno 16] Resource busy: '/dev/cu.SLAB_USBtoUART'
The terminal process "platformio 'device', 'monitor', '--environment', 'wemosbat'" terminated with exit code: 1.

I only use Visual Code with PlatformIO, tried many suggestions: disconnect and connect USB cable, close terminals, reset Visual Code, kextunload, googled at many sites and nothing.

Suddenly, I don’t know why, I got upload the bin or open the serial monitor. But when I need to connect to serial port again, the port is busy.

Isn’t there any way to reset the serial port?

All the best

manuelbl · April 15, 2021, 7:16am

See Mac USB port detected but won’t upload - #2 by manuelbl

programonauta · April 16, 2021, 12:07am

@manuelbl, I will answer your question here, due as new user I cannot post more than three replies in the same topic.

$ ls -l /Library/Extensions/*USB*
ls: /Library/Extensions/*USB*: No such file or directory

$ ls -l /System/Library/Extensions/*USB*
/System/Library/Extensions/AppleMIDIUSBDriver.plugin:
/System/Library/Extensions/AppleOSXUSBNCM.kext:
/System/Library/Extensions/AppleUSBACM.kext:
/System/Library/Extensions/AppleUSBAudio.kext:
/System/Library/Extensions/AppleUSBCDC.kext:
/System/Library/Extensions/AppleUSBCommon.kext:
/System/Library/Extensions/AppleUSBDMM.kext:
/System/Library/Extensions/AppleUSBDisplays.kext:
/System/Library/Extensions/AppleUSBECM.kext:
/System/Library/Extensions/AppleUSBEEM.kext:
/System/Library/Extensions/AppleUSBEthernet.kext:
/System/Library/Extensions/AppleUSBEthernetHost.kext:
/System/Library/Extensions/AppleUSBFTDI.kext:
/System/Library/Extensions/AppleUSBMultitouch.kext:
/System/Library/Extensions/AppleUSBNCM.kext:
/System/Library/Extensions/AppleUSBNetworking.kext:
/System/Library/Extensions/AppleUSBSerial.kext:
/System/Library/Extensions/AppleUSBTopCase.kext:
/System/Library/Extensions/AppleUSBWCM.kext:
/System/Library/Extensions/AppleUSBiBridge.kext:
/System/Library/Extensions/IOUSBAttachedSCSI.kext:
/System/Library/Extensions/IOUSBFamily.kext:
/System/Library/Extensions/IOUSBHostFamily.kext:
/System/Library/Extensions/IOUSBMassStorageClass.kext:
/System/Library/Extensions/IOUSBMassStorageDriver.kext:

manuelbl · April 16, 2021, 5:50am

Very strange. According to this list, you don’t have a driver for your board. Does it still appear as /dev/cu.SLAB_USBtoUART when plugged in?

If so, show the output of:

ls -l /Library/Extensions

programonauta · April 16, 2021, 9:54pm

Hi @manuelbl,

After remove the library, as you suggested:

sudo kextunload /Library/Extensions/SiLabsUSBDriver.kext/
sudo rm -rf /Library/Extensions/SiLabsUSBDriver.kext/

nothing happens when I plugged the board:

$ ls -la /dev/cu*
crw-rw-rw-  1 root  wheel   21,   1 Apr 15 15:19 /dev/cu.Bluetooth-Incoming-Port

/dev/cu.SLAB_USBtoUART only appear if I install Silabs driver and plug the board.

$ ls -l /Library/Extensions/  # after remove Silabs Driver
total 0
drwxr-xr-x  3 root  wheel  102 Apr 24  2018 ACS6x.kext
drwxr-xr-x  3 root  wheel  102 May  8  2018 ATTOCelerityFC8.kext
drwxr-xr-x  3 root  wheel  102 May  7  2018 ATTOExpressSASHBA2.kext
drwxr-xr-x  3 root  wheel  102 May  7  2018 ATTOExpressSASRAID2.kext
drwxr-xr-x  3 root  wheel  102 Sep  6  2017 ArcMSR.kext
drwxr-xr-x  3 root  wheel  102 Apr 15 15:09 CP210xVCPDriver.app
drwxr-xr-x  3 root  wheel  102 Sep  1  2013 CalDigitHDProDrv.kext
drwxr-xr-x  3 root  wheel  102 May  3  2018 HighPointIOP.kext
drwxr-xr-x  3 root  wheel  102 Dec  5  2017 HighPointRR.kext
drwxr-xr-x  3 root  wheel  102 Mar 31  2017 PromiseSTEX.kext
drwxr-xr-x  3 root  wheel  102 Apr 24  2018 SoftRAID.kext
drwxr-xr-x  3 root  wheel  102 Nov  5  2015 SteamInput.kext
drwxr-xr-x  3 root  wheel  102 May  8  2015 TACC.kext
drwxr-xr-x  3 root  wheel  102 Aug 14  2013 hp_io_enabler_compound.kext
drwxr-xr-x  3 root  wheel  102 Jul  4  2018 usbserial.kext

$ ls -l /Library/Extensions/ # after reinstall Silabs driver
total 0
drwxr-xr-x  3 root  wheel  102 Apr 24  2018 ACS6x.kext
drwxr-xr-x  3 root  wheel  102 May  8  2018 ATTOCelerityFC8.kext
drwxr-xr-x  3 root  wheel  102 May  7  2018 ATTOExpressSASHBA2.kext
drwxr-xr-x  3 root  wheel  102 May  7  2018 ATTOExpressSASRAID2.kext
drwxr-xr-x  3 root  wheel  102 Sep  6  2017 ArcMSR.kext
drwxr-xr-x  3 root  wheel  102 Apr 15 15:09 CP210xVCPDriver.app
drwxr-xr-x  3 root  wheel  102 Sep  1  2013 CalDigitHDProDrv.kext
drwxr-xr-x  3 root  wheel  102 May  3  2018 HighPointIOP.kext
drwxr-xr-x  3 root  wheel  102 Dec  5  2017 HighPointRR.kext
drwxr-xr-x  3 root  wheel  102 Mar 31  2017 PromiseSTEX.kext
drwxr-xr-x@ 3 root  wheel  102 Mar 25 08:23 SiLabsUSBDriver.kext
drwxr-xr-x  3 root  wheel  102 Apr 24  2018 SoftRAID.kext
drwxr-xr-x  3 root  wheel  102 Nov  5  2015 SteamInput.kext
drwxr-xr-x  3 root  wheel  102 May  8  2015 TACC.kext
drwxr-xr-x  3 root  wheel  102 Aug 14  2013 hp_io_enabler_compound.kext
drwxr-xr-x  3 root  wheel  102 Jul  4  2018 usbserial.kext

It’s important to notice that I get upload and open serial monitor with SiLabs driver. The problem is if I try to upload or open monitor several times. Example: I upload the binary to the board, if I try to open serial monitor, I need to repeat the process: unplug, plug, until Error 16 (Resource Busy) disappear. And I cannot identify what exactly happens before I got the connection.

I’ve already tried to

# unplug the board
sudo kextunload /Library/Extensions/SiLabsUSBDriver.kext/
sudo kextload /Library/Extensions/SiLabsUSBDriver.kext/
# plug the board

But even with this procedure I got resource busy error (but as I said before, some times it works).

Doing more testes, in some times I cannot unload driver even with board disconnected

# unplug the board
$ sudo kextunload /Library/Extensions/SiLabsUSBDriver.kext/
(kernel) Can't unload kext com.silabs.driver.CP210xVCPDriver; classes have instances:
(kernel)     Kext com.silabs.driver.CP210xVCPDriver class com_silabs_driver_CP210xVCPDriver has 1 instance.
Failed to unload com.silabs.driver.CP210xVCPDriver - (libkern/kext) kext is in use or retained (cannot unload).

manuelbl · April 17, 2021, 8:19am

That’s valuable information and a new perspective. So it has been working but not consistently.

So my conclusion would be: You need the proprietary SiLabs drivers and they are working. The cause of the “Resource busy” problem is that a program does not properly release the serial port when it’s done. Possibly, the program is stuck.

Am I correct in assuming you are accessing the serial port with PlatformIO tools only: upload from PlatformIO, serial monitor of PlatformIO, possibly debugging from PlatformIO? Are you using PlatformIO from within Visual Studio Code?

If so: In a typical cycle of upload, monitor, upload, monitor: Is it always the upload action that fails? Or can it affect the serial monitor as well?

programonauta · April 17, 2021, 4:05pm

Hi @manuelbl

Yes I’m using Platform IO within Visual Studio Code.

Digging some solution, I found out a folder named Troubleshooting in dmg file downloaded form Silabs site.

Inside this folder there is another package. So before installing it, I removed all references to installed driver, and reboot the system.

I Installed it (the screen installations is bit different than other), and reboot the system again.

So far, it’s working well. I get upload, open serial monitor, several times in a row, without unplug the board.