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Looking around for possible solutions for long distance communication between multiple microcontrollers I found the CAN bus. However, it says that there is a licensing fee for any implementation of the CAN protocol.

My plan is to use a microcontroller, a CAN controller (MCP2515), and a CAN transceiver (MCP2561) for each node to communicate on the network.

Do I have to pay the CAN licensing fee, or is it already paid for by the manufacturer of the CAN controller and transceiver?

Thanks in advance

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It's included in the cost of the parts.

It's a lot easier to collect money from a few IC makers than from every person who makes a product using those parts.

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  • \$\begingroup\$ Ok, it makes more sense now. I thought designing a PCB with elements that use the CAN protocol would require me to get a license, but it seems to only apply to the manufacturer of the individual chip that implements the protocol \$\endgroup\$ – ihenn Feb 10 '17 at 10:38
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If you are using a third-party CAN controller chip, then they will have paid the licensing fee. The original patents related to the way the controller worked, so the vendor requires a license in order to sell a controller chip without infringing the patents.

However, the original CAN 2.0 specification was published in 1991, so the patents (sorry I can't find a list of them) would have expired by now. This means that even if you wanted to implement your own controller in software/hardware you wouldn't have to pay any licensing fee, provided you didn't call it 'CAN' or use any of Bosch's other trademarks. Note that this is essentially what Atmel did with the 'Two-Wire-Interface' - otherwise known as I2C(TM) - when Philip's I2C patents expired.

It appears that Bosch has significantly reduced the licensing fees in light of this which is why I imagine vendors continue to use the official 'CAN' brand. Also note that CAN FD enhancements are covered by later patents which I believe are still in effect.

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  • \$\begingroup\$ The manufacturers of the chips can not infringe and be legally using the technology covered in a patent (i.e. be legitimately using the technology under a valid licensing agreement). Infringe: "actively break the terms of (a law, agreement, etc.)." \$\endgroup\$ – Makyen Feb 10 '17 at 16:11
  • \$\begingroup\$ @Makyen "that would infringe these patents [if the vendor did not have a license]" \$\endgroup\$ – user253751 Feb 11 '17 at 10:27
  • \$\begingroup\$ @immibis, After I left my comment, the answer was edited. I agree that the addition of that "would" changes how the sentence reads. However, it is now awkward. I have suggested an edit. \$\endgroup\$ – Makyen Feb 11 '17 at 16:34
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License form Your link apply to integrated circuits and IP cores only:

The right to use the CAN Pr otocol, CAN FD Protocol intellectual property rights for the design, manufacture and sale of integrated circuits or the programming of FPGAs

You don't have to pay anything if You are using already available IC's.

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