Good intro article. I have tried your DRV2603 LRA driver and it works very well. I would be interested in a follow up article that goes into detail about how auto-tune resonant frequency detection works.
It did take a bit to understand what the actual subject was, it is quite interesting. I can visualize at least one way to track the actual resonant frequency, I am sure that there are a few more. The simplest way is to use the device in the feedback loop of it's driving oscillator, like the tuning fork oscillators used in the past. That would be the cheap and easy approach and it would not need a microcontroller or any software to make it work. So probably nobody would want to do it that way.
It looks like everybody else calls these linear resonant actuators, not accelerators. Once I figured out the terminology difference, it was much easier to find more information about their applications.
Replay available now: A handful of emerging network technologies are competing to be the preferred wide-area connection for the Internet of Things. All claim lower costs and power use than cellular but none have wide deployment yet. Listen in as proponents of leading contenders make their case to be the metro or national IoT network of the future. Rick Merritt, EE Times Silicon Valley Bureau Chief, moderators this discussion. Join in and ask his guests questions.