[q3k]

One way they could do this is grant you a patent license only for some kinds of use.

(and eg. make sure their products are useless without some patent license for some software driver or algorithm)

[limagnolia]

Patents are exhausted on first sale. If you sell me a board that uses your patent, I can do anything I want with that board. At least that is my understanding, IANAL and all...

However, if they are distributing SDKs or something separately from the hardware, that software could have its own license that forbids commercial use.