Microsoft Code PlatformIO extension conflicts with brltty Ubuntu 22.04 LTS (USB ID 1a86:7523)

[Rob Somerville]

When using the PlatformIO extension within Microsoft Visual Studio Code to upload firmware to a ESP32 based microcontroller attached via USB, the upload fails with the following repeated error messages in syslog:

"brltty: Ignored Byte: xx" Where xx is a different hexadecimal value.

The problem manifests itself with a timeout and a "Looking for upload port...
Error: Please specify `upload_port` for environment or use global `--upload-port` option." message in PlatformIO.

This error was not present in Ubuntu prior to upgrading to 22.04.

Steps taken to resolve:

1. Changed USB cable between powered hub and microcontroller
2. Attempted upload with USB hub powered off
3. Attempted upload from other USB ports
4. Defined USB port microcontroller is connected to in platformio.ini by adding the parameter "upload_port = /dev/ttyUSB0"

Current workaround:

Uninstall the brltty package:

"sudo apt remove brltty"

[Steve Langasek (vorlon)]

Your log shows:

Apr 28 19:03:14 HIDDEN kernel: [ 1063.197438] usb 3-2.1: new full-speed USB device number 7 using xhci_hcd
Apr 28 19:03:14 HIDDEN kernel: [ 1063.321857] usb 3-2.1: New USB device found, idVendor=1a86, idProduct=7523, bcdDevice= 2.64
Apr 28 19:03:14 HIDDEN kernel: [ 1063.321866] usb 3-2.1: New USB device strings: Mfr=0, Product=2, SerialNumber=0
Apr 28 19:03:14 HIDDEN kernel: [ 1063.321869] usb 3-2.1: Product: USB Serial

And /lib/udev/rules.d/85-brltty.rules says:

# Device: 1A86:7523
# Baum [NLS eReader Zoomax (20 cells)]
ENV{PRODUCT}=="1a86/7523/*", ENV{BRLTTY_BRAILLE_DRIVER}="bm", GOTO="brltty_usb_run"

What is the device in question? /usr/share/misc/usb.ids says it is QinHeng Electronics, "CH340 serial converter" which does sound too generic for brltty.

[Rob Somerville (linuxgreybeard)]

Hi Steve,

The error log was from using an A-Z Delivery Lolin ESP32. The same error also occured with a different ESP32 Dev kit C board which uses a different vendor ID:

Apr 28 22:36:36 kernel: [13865.012999] usb 3-2.1: new full-speed USB device number 13 using xhci_hcd
Apr 28 22:36:36 kernel: [13865.168520] usb 3-2.1: New USB device found, idVendor=10c4, idProduct=ea60, bcdDevice= 1.00
Apr 28 22:36:36 kernel: [13865.168530] usb 3-2.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
Apr 28 22:36:36 kernel: [13865.168534] usb 3-2.1: Product: CP2102 USB to UART Bridge Controller
Apr 28 22:36:36 kernel: [13865.168537] usb 3-2.1: Manufacturer: Silicon Labs
Apr 28 22:36:36 kernel: [13865.168539] usb 3-2.1: SerialNumber: 0001
Apr 28 22:36:36 kernel: [13865.176949] cp210x 3-2.1:1.0: cp210x converter detected
Apr 28 22:36:36 kernel: [13865.177773] usb 3-2.1: cp210x converter now attached to ttyUSB0

(This entry being from syslog with brltty unistalled).