Cannot open device

[carlbennettnz]

When I run new PowerMate() I get the following error from line 36 of powermate.js:

cannot open device with path USB_077d_0410_14530000`

Line 36:

this._hidDevice = new HID.HID(powerMateHIDdevice.path);

console.logging powerMateHIDdevice gives be the following:

{ vendorId: 1917,
  productId: 1040,
  path: 'USB_077d_0410_14530000',
  serialNumber: '',
  manufacturer: 'Griffin Technology, Inc.',
  product: 'Griffin PowerMate',
  release: 1024,
  interface: -1 }

Any idea what’s going wrong?

[sandeepmistry]

@carlbennettnz what OS are you running it on?

[carlbennettnz]

OS X. I tired again however and this time it worked. I had the Griffin PowerMate app open the first time I tried, which was causing the problem. It seems obvious now, but it might be worth mentioning that in the readme.

[mattwelch]

Having the same issue, this time on Raspbian (Debian) on a Raspberry Pi. Here's the failure, along with a console.log:

{ vendorId: 1917,
  productId: 1040,
  path: '0001:0004:00',
  release: 1024,
  interface: 0 }

/home/pi/p/node_modules/node-powermate/powermate.js:34
  this._hidDevice = new HID.HID(powerMateHIDdevice.path);
                    ^
cannot open device with path 0001:0004:00

Any thoughts?

[sandeepmistry]

@mattwelch could any other programs be using it? Have you tried running as root?

If those don't work, we might be to ask the node-hid team.

[mattwelch]

Good call on the root. I tried that, and it worked great. Any idea of what my options are if I don't want to run as root? I think I need to put my and the hid in the same group.

[sandeepmistry]

You could try to chown/chmod the device if it shows up in /dev/...

I'm not sure how USB HID devices work in Linux, but I can take a closer look node-hid if you still need help.

[mattwelch]

For the record, on my platform (Raspbian/Debian) the problem was permissions, which were solved with a udev rule.

[sandeepmistry]

@mattwelch @carlbennettnz can we close this issue or is there something that needs to be added to the read me?

[mattwelch]

I'm fine closing it. Mine is a specific case (Raspbian, though likely the same for Debian/Ubuntu), for which I'd be glad to write up directions to be included.

[sandeepmistry]

@mattwelch it would be great if you could share the udev rule instructions!