SmartKnob – Haptic input knob with software-defined endstops and virtual detents
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Re: SmartKnob – Haptic input knob with software-defined endstops and virtual detents
#2Past submission from 2022 with a dozen comments:
Re: SmartKnob – Haptic input knob with software-defined endstops and virtual detents
#3there was a microsoft surface dial, not sure if that ever took off or not. I thought there was another product that had this form factor
Re: SmartKnob – Haptic input knob with software-defined endstops and virtual detents
#4This is great! I've been thinking about building something similar for sleep training with my toddler--need something that works in a dark room by feel and has variable intervals. Love it.
Re: SmartKnob – Haptic input knob with software-defined endstops and virtual detents
#5I absolutely love that this is open source hardware; there have been multiple circuits available on the web for this kind of peripheral, but nothing even approaching the level of polish that this has.
If the designer happens to be here, I have a question regarding the circuit. Is there any protection against voltage produced by a user's rotation of the knob? The TMC6300 IC that the schematic shows is directly connected to the BDCM without any intermediate circuitry, but the only 'protections' listed in its datasheet are related to failures related to the motor being used as a motor, not as a generator.
Re: SmartKnob – Haptic input knob with software-defined endstops and virtual detents
#6I definitely need a use case for that
Re: SmartKnob – Haptic input knob with software-defined endstops and virtual detents
#7I absolutely love that this is open source hardware; there have been multiple circuits available on the web for this kind of peripheral, but nothing even approaching the level of polish that this has. If the designer happens to be here, I have a question regarding the circuit. Is there any protection against voltage produced by a user's rotation of the knob? The TMC6300 IC that the schematic shows is directly connect…
Designer here - I will admit that I just do this as a bit of a hobby and I'm not an EE, so I don't have a great answer for you, but generally speaking since this is a high resistance/low KV motor and there's only so fast you could spin it by hand realistically, I think the voltages you could generate that way shouldn't be so high as to cause damage in most cases. The TMC6300 datasheet does show it directly connected to the BLDC motor so that's what I based this design on.
There are probably some best practices that I'm missing though (diode on the main supply maybe?), so if anyone knowledgeable wants to chime in, I'm all ears! (Or I suppose pull requests are welcome too).
Re: SmartKnob – Haptic input knob with software-defined endstops and virtual detents
#8I absolutely love that this is open source hardware; there have been multiple circuits available on the web for this kind of peripheral, but nothing even approaching the level of polish that this has. If the designer happens to be here, I have a question regarding the circuit. Is there any protection against voltage produced by a user's rotation of the knob? The TMC6300 IC that the schematic shows is directly connect…
Designer here - I will admit that I just do this as a bit of a hobby and I'm not an EE, so I don't have a great answer for you, but generally speaking since this is a high resistance/low KV motor and there's only so fast you could spin it by hand realistically, I think the voltages you could generate that way shouldn't be so high as to cause damage in most cases. The TMC6300 datasheet does show it directly connected…
Interactions like these are the reason why HN is so worth reading!
Re: SmartKnob – Haptic input knob with software-defined endstops and virtual detents
#9I definitely need a use case for that
Control panels for various hardware. I could think of many uses in music synthesizers for example where access to many parameters for quick modification during live performance can make the difference.
Re: SmartKnob – Haptic input knob with software-defined endstops and virtual detents
#10I definitely need a use case for that
Control panels for various hardware. I could think of many uses in music synthesizers for example where access to many parameters for quick modification during live performance can make the difference.
On a related music/audio note, I recently came across videos of the teenage engineering TP-7 which looks like a really cool application of similar haptic feedback concepts. Unfortunately it's out of the price range where I can justify picking one up just to tinker around with it, so I've only seen videos of it so far.