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I am working on a small experiment on a closed loop DC motor for speed control. The DC motor is separately excited and fed through a DC chopper.

I would like to know what are the best micro-controllers best suitable for this project?

Marcus Müller
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Arthur D. Zambezi
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    What kind of DC motor? Also, this question borders perilously close to a shopping question the way it is worded, which is off topic here. Instead, ask for and peripherals features you should be looking for. Also, I suspect you are starting from the wrong end: Picking the MCU first then figuring out what you need tp drive the motor. Figure out what you need to control the motor first then pick the MCU – DKNguyen May 27 '20 at 20:43
  • a good servo needs good specs for acceleration , inertia , braking then tach and current feedback. Not a uC. Then choose half or full bridge, g, v control limits and dual feedback, overshoot criteria etc. – Tony Stewart EE75 May 27 '20 at 20:48
  • Look for a microcontroller that includes one or more motor controller peripheral units. The first one I ever saw dates back a long time ago -- the [Motorola 32k](https://en.wikipedia.org/wiki/NS320xx). Since then, many many different MCUs include fairly fancy peripherals for motor control. Focus on those. Kits offered by the manufacturers usually exist to demonstrate their capabilities and to provide you with educational opportunities to "doing it well." Take advantage of all that, as well. – jonk May 27 '20 at 20:49
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    @jonk I wouldn't recommend "fancy" peripherals to a beginner. Basic timer with PWM is quite sufficient for most, even quite demanding, PID applications. More advanced (but fairly common) timer with waveform generation covers all the rest. It is only for sensorless BLDC motors one would look for additional features, like opamps and comparators – Maple May 27 '20 at 20:54
  • @Maple :) What's not to like about fancy peripherals? Anyway, the OP doesn't really say much of anything, so I'm not sure how any advice is better or worse at this point. :) – jonk May 27 '20 at 20:58
  • @jonk I _love_ fancy peripherals, especially when they save board space. I once used $6 more expensive chip only to get rid of two $0.05 resistors. My boss was shocked :) I'm just not sure it is good for "small experiment" kind of project – Maple May 27 '20 at 21:08
  • _"...fed through a DC chopper"_ - how is the DC chopper controlled? What will you be using to measure motor speed? – Bruce Abbott May 27 '20 at 22:07
  • Rephrase your question to "how should I choose a processor to drive a DC motor" and I'll vote to reopen. As it is it's both a shopping question and highly opinion-based. – TimWescott May 27 '20 at 23:31
  • `I would like to know what are the best micro-controllers best suitable for this project?` ... you didn't say what the project is .... right now, your post is like `I'm building a car. What's the best engine to use.` ... see? no information at all – jsotola May 28 '20 at 00:00

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Assuming a brushed DC motor, if you're planning on tachometer feedback a quadrature encoder peripheral would be a good thing to have. On-chip ADC may or may not be adequate for the analog inputs- current and maybe rail voltage for feed-forward.

Speed control, as opposed to position control, generally is pretty undemanding and I suspect most 8-bit, 16-bit or 32-bit MCUs with PWM and quadrature encoder peripheral would be acceptable in most situations.

Using a 32-bit micro would allow more sophisticated control algorithms or easy implementation of simpler ones. You can get a Cortex M4 with single precision FPU for only a few dollars these days so that might be a logical way to proceed- though the complexity of firmware development is an order of magnitude above something like PIC you don't need to worry much about execution time and could probably use an RTOS if that's your bent. Although it's possible to buy processors with (relatively) prototyping-friendly 64-lead LQFP packages, an evaluation board would be a lot easier if you're not comfortable with that kind of thing, then only the power devices would need a PCB.

Spehro Pefhany
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