silly microcontroller question

[pseudolobster]

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.

 

[MarioMaster]

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]

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.

 

[Bionic-Badger]

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]

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

 

[woop]

AKA, PWM  

indeed, but you need feedback for proper current control.