Variable resistance

Comments

• Larry Posts: 212

  2004-10-27 06:47 edited 2004-10-27 06:47

  Hmm- interesting concept, "outputting" resistance. Maybe you should explain your application a bit. there may be other ways to deal with your situation, such as using PWM to control voltage instead. Ends up being the same thing with E=IR
  
  If controlling resistance is really what you need to do, Dallas semiconductor makes the DS1804. The chip is a potentiometer thay you can control with microcontoller signals. It will require 2 pins to run one, plus an additional pin for each chip if you run more than one.
  
  Larry
  
  ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
  
• Bruce Bates Posts: 3,045

  2004-10-27 06:49 edited 2004-10-27 06:49

  Eric R-
  
  Sure can output a variable resistance. Take a look at using a digital potentiometer. They come in various resistance ranges, some have volatile settings and other save them. There are a number of different methods of adressing them including SPI, such that you can use Shiftin/Shiftout or bit-bang them if necessary. Maxim/Dallas [noparse][[/noparse]wwww.maxim-ic.com] and Xicor [noparse][[/noparse]www.xicor.com] are two good places to start looking.
  
  Regards,
  
  Bruce Bates
• Eric R Posts: 225

  2004-10-29 03:52 edited 2004-10-29 03:52

  Thanks guys! Guess I got ahead of the game. Got 3/4 of the way into the WAM book and found this info further back yet! Looks like the AD5220 should work fine.