Linux Power savings for Scanners

installed a scanner Canoscan 9000F Mark II on Ubuntu 16.04. I was not straightforward because the vendor, Canon, has the nerve of NOT providing a driver for the device.

drivers scanner Canoscan 9000F
Drivers information on Canon website about the Canoscan 9000F Mark II

Unfortunately SANE (Scanner Access Now Easy) did not help. It did not detect the scanner.

I downloaded a VueScan executable. The latter did detect the scanner but it would not preview or scan any document.

So I focused in fixing the communication of my Ubuntu 16.04 to the scanner.

I found this solution at https://ubuntu-mate.community/t/scanner-worked-in-15-10-does-not-work-in-16-04/4761/12

Go to the file tlp. Path /etc/default/tlp . You need to have writing rights.
You will find the line USB_BLACKLIST=
Search for it. Here it’s line 178.

Here i wrote the USB-ID after USB_BLACKLIST. Then remove the #-sign.
Like this:
USB_BLACKLIST=04a9:190d

The USB-ID you will get with lsusb in terminal.

Thank you Etamuk from Germany!

On your terminal:

$ lsusb

Bus 002 Device 023: ID 04a9:190d Canon, Inc. CanoScan 9000F Mark II

$ lsusb -v

There you have your scanner:

Bus 002 Device 023: ID 04a9:190d Canon, Inc. CanoScan 9000F Mark II
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x04a9 Canon, Inc.
idProduct 0x190d CanoScan 9000F Mark II
bcdDevice 0.02
iManufacturer 1 Canon
iProduct 2 CanoScan
iSerial 0
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 39
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xc0
Self Powered
MaxPower 2mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 3
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 0
bInterfaceProtocol 255
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x07 EP 7 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x88 EP 8 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x89 EP 9 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 11
Device Qualifier (for other device speed):
bLength 10
bDescriptorType 6
bcdUSB 2.00
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
bNumConfigurations 1
Device Status: 0x0001
Self Powered

The ID of that USB is 04a9:190d

I loved the ensuing message from wally333 thanking Etamuk and ranting:

“power management” has wasted so much of my time and effort over the years it’ll never break even in “energy savings”. Don’t get me started on the very arrogant “screen blanking” systems and protocols…

🙂

 

 

Flight corridors of commercial aviation

I used to telecommute weekly from Madrid to London and back. Flying into London from Monday to Thursday became part of my lifestyle for a long time.

The itinerary Madrid (Terminal 1) to London Gatwick (South Terminal) and viceversa was part of my routine to the point that I knew the codes of my flights by heart.

Landing on Barajas from airplane
Arriving at Barajas airport

During the first flights Gatwick-Barajas I realised that the airplanes consistently flew over the same landmarks: isle of Wight in England, across Bretagne in France and over Santander in Spain.

GPS tracking on an airplane
Using a smartphone as a GPS tracker on an airplane

I wondered if that meant that there are “air corridors” or airways in the sky that flights with the same code followed consistently.
In order to validate this hypothesis I started to track the path of the flights with a GPS tracker.

GPS tracking during the flights

The GPS tracking device of choice was my smartphone. I switched off my smartphone at take-off and at landing times because it was mandatory by the airline.

I switched on my smartphone when the signals in the cabin allowed the passengers to do so. The GPS signal is compatible with the airplane mode  because GPS tracking does not transmit radio waves. The smartphone only receives GPS data and does send anything back to the satellites.

I recorded the coordinates of most of the duration of 6 flights in the interval of 24 days from mid February to mid March. The direction of the flights were 4 flights from Gatwick to Barajas and 2 flights from Barajas to Gatwick.

I learned a few things that I am listing here:

Satellite fix

The fixing of satellites takes much longer than on the ground

Unpredictable GPS tracking

The GPS tracking is not complete or not happening at all in some flights. Does it depended on the fuselage of the airplane or are GPS jammering devices increasingly common in commercial flights?

In some instances I might not get coordinates for hundreds of kilometers, for instance from Castille inland to the middle of the Bay of Biscay.

Similar paths on same airways

The airways were similar but not identical between flights on the same route even if separated by only 7 or 14 days.

flight paths Gatwick-Barajas and Barajas-Gatwick
Comparison of airways from Gatwick to Barajas and viceversa

The airways were close by a few kilometers and degrees.

Airways over Bretagne on the same flight itineraries
Airways over Bretagne on the same flight itineraries

Landmarks of the flights Gatwick-Barajas

Gernsey and Santander and, exceptionally Gernsey-Gijón-León.

Landmarks of the flights Gatwick-Barajas
Landmarks of the flights Gatwick-Barajas

Landmarks of the flights Barajas-Gatwick

Bilbao and Jersey.

Landmarks of the flights Barajas-Gatwick
Routes of the flights Barajas-Gatwick

Unreliable elevation values

The values of the elevation are zero for 50% or more of the total points of a track. Where not zero, the values were 900-1100 meters with a maximum of 1500 meters. The values that I saw displayed on the screens for passengers were 10500 meters however.

I used GpsPrune v. 18.5 by Activity Workshop to display the coordinates and maps from a .gpx export of the GPS file. GpsPrune is a program for loading, displaying and editing data from GPS receivers.