Pyusb - Errno 13 Access denied for control transfer - Mac OS X

Question

I am trying to send a transfer control command via pyusb on top of Mac OS: dev.ctrl_transfer (0x21,0x09,0x0200,0x0,0x1)

I get an error message:

Traceback (most recent call last): File "./main.py", line 21, in <module> dev.ctrl_transfer(0x21,0x09,0x0200,0x0000,0x0001) File "/Library/Python/2.7/site-packages/usb/core.py", line 962, in ctrl_transfer self._ctx.managed_claim_interface(self, interface_number) File "/Library/Python/2.7/site-packages/usb/core.py", line 146, in managed_claim_interface self.backend.claim_interface(self.handle, i) File "/Library/Python/2.7/site-packages/usb/backend/libusb1.py", line 747, in claim_interface _check(self.lib.libusb_claim_interface(dev_handle.handle, intf)) File "/Library/Python/2.7/site-packages/usb/backend/libusb1.py", line 552, in _check raise USBError(_strerror(ret), ret, _libusb_errno[ret]) usb.core.USBError: [Errno 13] Access denied (insufficient permissions) 

Can someone help me with this. I tried sudo, su. I also posted this in the pyusb github user group. I got this (adding myself to the plugdev group on Debian systems) as a possible solution, but I'm not sure how to continue working with Mac OS https://github.com/braiden/python-ant-downloader/issues/30#issuecomment -55293142

Related to the following questions:

OUT endpoint unavailable pyusb

PyUSB dev.set_configuration () (solution for ubuntu)

Answer 1

As far as I think, the answer to the following question:

Does python LibUsb work on HID devices in Mac OS X?

This is not true. It seems that libusb cannot be used on Mac to access HID devices, and you should use the HIDAPI library or the like.

I assume that you are trying to access a HID device on Mac OS X using libusb, which is somehow forbidden by the sacred laws of nature.

HID Mac OS X Docs

Ticket on libusb

A similar question: Raw access to HID devices in OS X