A buddy of mine dropped me a link to TI’s new brushed DC motor driver with sensorless speed control, the DRV8214. I spent a few minutes trying to hunt down the mechanism they use to derive speed from back EMF because it’s such an intriguing idea, and the datasheet proper is slightly cagey abut it… but it looks like they’ve fundamentally figured out how to build in the sensing and control loop from the filtered ripple counter mechanism (PDF) they previously published a guide for doing with discrete H-bridge/current sense/op amp/comparitor ICs and an MSP430 microcontroller directly into a $3-in-single-quantity I2C addressable chip.
It even has stall detection that looks good enough to potentially use for sensor-less homing.
Interfacing to a host micro is fairly pin-and-peripheral intensive, but this seems like good magic.
Web Presence
Page Navigation
Meta
April 2025 S M T W T F S 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 -
Recent Posts
Random Quote
I’ve always lived cheaply. I live like a student, basically. And I like that because it means that money is not telling me what to do. I can do what I think is important for me to do. It freed me to do what seemed worth doing. So make a real effort to avoid getting sucked into all of the expensive lifestyle habits of typical Americans … because, if you do that, then the people with the money will dictate what you do with your life. You won’t be able to do what’s really important to you.
— Richard Stallman (RMS)Categories
License
Unless otherwise noted, this work is licensed under a Creative Commons Attribution-ShareAlike 3.0 United States License.