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has anyone out there written....

a usb driver for a hardware controller with numerous controls (around 25) to work with mac os x?

I need to put a price on the creation of such a beast, unfortunately my experience with writing drivers of any kind is non-existent.

also if anyone out there has any experience at all in writing drivers for any OS, any pointers, advice or anecdotes would be very much appreciated :)

regular poster
Saturday, June 12, 2004

Has this device been designed yet?  If not and if it's possible to shoehorn what it should do into the USB HID class then you probably don't need a custom driver.  The HID class is versatile so lots of stuff can use it.  There are also other standard classes like audio and mass storage.  See for more.

I've never written drivers myself but have done a decent amount of reading on the subject.  You'll probably need to know C and be familar with concepts related to interrupts, reentrancy and threading among numerous others.  The learning curve is generally regarded as steep.  The price of failure is an unstable system.

Saturday, June 12, 2004

If you've never written drivers before, I wouldn't be bidding to do it. Honestly, bad drivers are just an awful thing for user experience, much worse than merely buggy software.

Brad Wilson (
Saturday, June 12, 2004

Use the FTDI USB chips ( as the basis for the hardware interface. The chips are cost-effective, staggeringly easy to use, and the free drivers just work. Any other way of doing USB is for masochists or somebody with really way-out needs. And since ftdi have written the drivers already for most platforms, it's easy to go porting...
But they're no good if you need high-speed USB 2

If you can't change the hardware, then writing drivers is _hard_work_ if you haven't done it. Price it at 2-3 months work and expect to take twice that.

hardware guy
Sunday, June 13, 2004

Please, don't do a commercial end-user driver as your first-ever learning project!!! Thank you.

I absolutely HATE buggy drivers. I've had enough blue screens for my entire life already.

But as a regular JOS reader, you would probably test it well enough, so maybe there's no problem after all...

irregular poster
Sunday, June 13, 2004

(Yeah, I know, but the OP specifically stated "any OS"... )

- former car owner in Queens
Monday, June 14, 2004

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