Hardware: simple utility for send hex commands to usb device

[thelusiv]

More progress on this front...I finally got a good usbsnoop.log and parsed it with grep and less. Turns out that the commands to set the wheel range are the same for the DFP as they are for the G25. I see the value

Code:

0xf8818403000000

go by when the wheel is set to 900-degree mode, and

Code:

0xf8812800000000

when the wheel is set to 40-degree mode.

Now the big question is, why didn't this work for me when I tried it with my DFP before? I guess it's time to try it again, but will have to wait, I'm tired...


edit: here are some formulas for setting the axis-range on the DFP/G25. The command is prefixed by four bytes "f881", followed by four bytes representing the range value, followed by 6 bytes of 0-padding. The 4-byte range value can be found via the following formula (converting the result to integer and expressed as hex):

Code:

range_value = (degrees - 40) * (23555 / 860) + 10240

For example, the range_value of 600 degrees would be

Code:

range_value = (600 - 40) * (23555 / 860) + 10240 = 25578

The formula for finding the range in degrees for a given range value is thus:

Code:

degrees = (range_value - 10240) * (860 / 23555) + 40

and an example, range_value of 33795 (0x8403) degrees:

Code:

degrees = (33795 - 10240) * (860 / 23555) + 40 = 900

edit 2: most of the above info is crap, good info follows...