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ArcticMyst Security by Avery

silly microcontroller question

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I've never really worked with microcontrollers before, and I'm not 100% on the basic principles of electronics, so pardon my ignorance if this is a dumb question.
Is there a way to digitally control resistance via a microcontroller?

I thought it would be a neat idea to have a set of "up" and "down" buttons on a driver to adjust current in say 10mA increments.
 





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they make components called digital potentiometers, it's basically a small chip with a ton of resistors inside it connected to a bunch of transistors and assorted logic, you power the chip and apply a direction signal (up or down) and a clock signal to move the virtual wiper

short answer: yes
 

woop

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you could also program a microcontroller to pulse a transistor on and off to get an average current, then smooth it out with an inductor and capacitor.
in effect it would be a 'buck' smps

but it would take a lot of programming experience to get it to work.
 
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The easiest thing to do is use the digital pot. They're not too expensive and have decent resolution. Many use the SPI protocol, so it'll be helpful to find a microcontroller that supports that natively. You may also wish to use a non-volatile version so it remembers its setting when you power down.
 

Things

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woop said:
you could also program a microcontroller to pulse a transistor on and off to get an average current, then smooth it out with an inductor and capacitor.
in effect it would be a 'buck' smps

but it would take a lot of programming experience to get it to work.


AKA, PWM ;)
 




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