Document Linux udev setup in README.md

[islemaster]

I'm attempting to get the RGB demo up and running with an Adafruit Circuit Playground board. I've already added Circuit Playground's VID and PID to serial.js as mentioned in #13. When I click the "Connect" button I can select my device, but then the error handler prints SecurityError: Access denied.

The only time SecurityError is mentioned in the WebUSB spec is in Section 4 - Device Enumeration under the section starting 'To request the "usb" permission...'

If the algorithm is not triggered by user activation, reject promise with a SecurityError and abort these steps.

I'm definitely interacting when this error occurs, so I'm not sure where my setup is going wrong.

• Attempting at commit ff4aae6
• On Ubuntu 17.04 64-bit
• Using Google Chrome 58.0.3029.96 (Official Build) (64-bit) with flags --enable-experimental-web-platform-features and --enable-features=WebUSB
• I've followed the README instructions, including editing USBCore.h to enable USB 2.1.
• Uploaded sketch.ino to the Circuit Playground with no customizations, using Arduino IDE 1.8.1.
• Using http-server to run the demo page at http://localhost:8000/rgb/index.html
• Maybe notable: I don't get a notification from Chrome when I plug in the Circuit Playground.

Any ideas? Thanks!

[reillyeon]

There's a missing step in the setup instructions. On Linux you need to add a file containing the following line to /etc/udev/rules.d to tell the OS to set permissions on the device so that Chrome can open it,

SUBSYSTEMS=="usb", ATTR{idVendor}=="your VID here", ATTR{idProduct}=="your PID here", MODE:="0666"

I'm going to re-purpose this bug for documenting this in README.md.

[islemaster]

Interesting... I already had the following in /etc/udev/rules.d/99-adafruit-boards.rules, although it looks malformed compared to the rule you posted:

# Rule to make Trinket/Pro Trinket/Gemma/Flora programmable without running Arduino as root.
# Tested with Ubuntu 14.04 and 12.04.  Other distributions might need to update GROUP="dialout"
# to another group value like "users".
SUBSYSTEM=="usb", ATTR{idProduct}=="0c9f", ATTRS{idVendor}=="1781", MODE="0660", GROUP="dialout"

# Rule to blacklist Adafruit USB CDC boards from being manipulated by ModemManager.
# Fixes issue with hanging references to /dev/ttyACM* devices on Ubuntu 15.04.
ATTRS{idVendor}=="239a", ENV{ID_MM_DEVICE_IGNORE}="1"

Adding the rule you provided with correct Circuit Playground VID/PIDs swapped in...

SUBSYSTEMS=="usb", ATTR{idVendor}=="239a", ATTR{idProduct}=="8011", MODE:="0666"

...definitely gets me further than before. I still don't get a notification from Chrome on plug, but the RGB demo now gets as far as "Connected" and seems to think it's setting LED colors when I move the sliders. Unfortunately nothing seems to actually happen on the board. I'll keep experimenting and post here if I can work out how to control the LEDs.

[reillyeon]

If you look in chrome://device-log when you plug in your device there should be a log message explaining why it failed to read the landing page URL.

[justinmoon]

SUBSYSTEMS=="usb", ATTR{idVendor}=="your VID here", ATTR{idProduct}=="your PID here", MODE:="0666"

I'm having the same problem and adding this line doesn't have any effect.

The output of udevadm info -a -n /dev/ttyACM0 includes

  looking at device '/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0/tty/ttyACM0':
    KERNEL=="ttyACM0"
    SUBSYSTEM=="tty"
    DRIVER==""
...

It seems that my Arduino isn't a member of the "usb subsystem"?

Here's what the failures look like from the device-log:

I'm using a Feather M0. I did add the relevant { 'vendorId': 0x239a, 'productId': 0x800b } line to the filters array in serial.js. I also made the #define USB_VERSION 0x210 modification to USBCore.h

Your help would be greatly appreciated.

[justinmoon]

I was able to get it to run by following these instructions: https://learn.adafruit.com/adafruit-arduino-ide-setup/linux-setup

[xylo04]

I had a very smooth experience today using only README.md to get running with Linux, Chrome 83 and an Adafruit M0, with the exception of having to make a udev rule. What surprises me is that Arduino IDE is able to program and use the serial console just fine without the udev rule, but Chrome was just giving me the cryptic "SecurityError: Access denied" message.

I added /etc/udev/rules.d/51-adafruit.rules:

SUBSYSTEM=="usb", ATTR{idVendor}=="239a", GROUP="plugdev"

My OS user was already part of the plugdev group.

[gauntface]

Are you open to taking Pull Requests to add this to the README?

[reillyeon]

Yes.