IOError when trying to connect sensor to Raspberry Pi

[anuj-sp]

After following the instructions to install required packages and changing the dev rules, the CO2monitor() functions throws an IOError as open failed. The command and error log can be seen as follows:

python -c "import co2meter as c; m=c.CO2monitor(); print(m.info)"

The error log is:

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/usr/local/lib/python2.7/dist-packages/co2meter/co2meter.py", line 95, in __init__
    with self.co2hid():
  File "/usr/lib/python2.7/contextlib.py", line 17, in __enter__
    return self.gen.next()
  File "/usr/local/lib/python2.7/dist-packages/co2meter/co2meter.py", line 144, in co2hid
    self.hid_open(send_magic_table=send_magic_table)
  File "/usr/local/lib/python2.7/dist-packages/co2meter/co2meter.py", line 114, in hid_open
    self._h.open(self._info['vendor_id'], self._info['product_id'])
  File "hid.pyx", line 66, in hid.device.open
IOError: open failed

[richmidwinter]

I get the same, but on a Macbook Pro.

[richmidwinter]

Ah. Think it just means the device isn't connected.

Tried a different USB hub and it's working for me.

[davidskeck]

Hello, I got this same issue, but after updating the dev rules as shown in the README, it works as expected. Make sure you run sudo udevadm control --reload-rules && udevadm trigger as the root user by calling sudo su followed by the command, and then exit out of root.