OpenServo.com

[pixeltje]

I recently joined Open Servo Forum since I am interested in using the same design for a more powerful controller using brushless DC motors for UAV propulsion.

With respect to the TWI interface and the addressing of the slave Open Servo Controllers, I wonder if the following legal issue has been considered by all of you selling Open Servo Controllers to other members or integrating these servo controllers in robots, etc. commercially available:

"Philips controls the allocation of I2C addresses. It is the company's position that all chips that can talk to the I2c bus must be licensed. It does not matter how this interface is implemented. "

So if you want to create a slave device for commercial use i.e. sell these units publicly to others. these units should be licensed through the company.(Using Atmel's TWI solution seems not to bypass this issue for slave addressing).

[ginge]

Hi, and welcome.

In interesting question that we should probably look closely at. I don't think it is an issue, and here are my uninformed reasons why.

1) Atmel calls this a TWI module. It is a I2C workalike without the trademark licensing limitations. (a)

2) the Philips patent has lapsed, and people are free to use the term I2C, and implement as they wish. (b)

3) It would seem that you only have to pay philips NXP for a license to use the logo and for use of the trademark "I2C" (c)

4) I have emailed the IP licensing dept at Philips NXP and we shall see what they say. email address and details (d)

5) The OpenServo uses all addresses available to allow up to 127 devices. Registration of an address that Philips NXP keeps the database for is going to be neigh on impossible.

Does anyone else know anything other then my trawling of the internet regarding the Atmel "TWI" interface, and the legalities of the use therein?

(a) http://en.wikipedia.org/wiki/I%C2%B2C#Derivative_Technologies
(b) http://www.nxp.com/products/interface_control/i2c/licensing/
(c) http://www.esacademy.com/faq/i2c/general/i2ccopyr.htm
(d) http://forums.nxp.com/forums/viewtopic.php?p=9171#9171

Barry
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http://www.headfuzz.co.uk/
http://www.robotfuzz.co.uk/

[kbb]

I agree with what Barry has written. Except for the interpretation of (c) as 3. (c) says that the OSIF would require a license: however, I believe this web page dates from 2000, which is post October 2006 (see below) and so what it says in (c) no longer applies.

I have spent a couple of hours looking... The more I go over what I saw, the more I think that, since October 2006, there isn’t a licensing issue. But it is wise of Barry to check!

I2C protocol

All the discussions that I saw which were indicating that you need to “purchase a license” pre-date October 2006 and refer you to pages on the now “disused” Philips web site. This is mostly to the same page, which is now bounced to

http://www.nxp.com/products/interface_control/i2c/licensing/

Not the sort of thing you would expect to see if they did require licensing?

On the Wikipedia it says (terse statement interpreted as?) “As of October 1, 2006, no licensing fees are required to implement the I2C protocol”.

And if there were a problem, one could simply change all the "I2C"s to "TWI"s!

Kevin.