From their pricing FAQ[1]:

  19. Why do Picovoice engines require an internet connection?

  While data is processed offline, locally on-device, Picovoice engines call home servers to stay active and report the consumption for billing purposes only.

[1] https://picovoice.ai/pricing/

So... not offline.

That board doesn't have connectivity! If we had a way to connect to the internet without a connectivity chip I would have had a more exciting post!

Why if it is fully offline then why does the micro-controller need a license key? What does it use the key for? How can any monitoring/analytics take place?

I read the article and was interested but after clicking around the site I was thoroughly confused about billing/pricing/metering.

Picovoice runs on almost anything: web browsers, mobile, desktop, single board computers, and microcontrollers. For the platforms that have connectivity (i.e. almost anything aside from microcontrollers), we do call home for license management. This helps us keep the `Free Tier` free for personal users, hackers , and skunkworks projects, but make sure we get paid by enterprise customers with deployments at scale [1]. On a microcontroller like the one in this tutorial, there is NO connectivity option. Hence, in this specific case it is 100% offline with no license management. In other cases voice recognition is 100% offline but the call home for license management needs connectivity.

[1] https://picovoice.ai/pricing/

Then please explain the

> Picovoice engines call home servers to stay active and report the consumption for billing purposes only.

It sounds like he's saying that the key is hashed offline to check for validity, and doesn't actually verify it via server.

Yes, the board does not have a connectivity chip of any sort [1]. Even if one really wants to there is no way to connect to anything from this board.

[1] https://www.st.com/en/evaluation-tools/stm32f4discovery.html

I think that's because the libraries it uses are non-free (I haven't checked though). If I'm correct, that's more like a license key in that regard.

Although interestingly enough, the README for the linked repo (https://github.com/Picovoice/picovoice) states that "The SDK is licensed under Apache 2.0 and available on GitHub to encourage independent benchmarking and integration testing." While source isn't provided and only compiled binaries are provided, that should give you permission to flip some bits to skip a license check. However, they may make you agree to a stricter license to use their online training tools.

I'm sure smart people can find a way to hack this! But check my other comment, the chip does NOT have connectivity module. Don't take it from me. Read the ST's product spec.

[1] https://www.st.com/en/evaluation-tools/stm32f4discovery.html

Because all the training is made on a proprietary system (and the prices are high), the MCU is just running the model.

have you noted that there is `Free Tier` that cost you $0? You can train using that. For this tutorial the cost of board ($20) is all you need to pay. Same for personal projects and even small skunkworks projects within companies. Picovoice makes money from large-scale deployments done by device makers

[1] https://picovoice.ai/pricing/