Produce a variable voltage up to 12V

I have a motor that takes a voltage between 3.5 and 12V to control the speed that I would like to control from my arduino. After some research, the solution I came up with was getting a 12V digital potentiometer, connecting Vcc to a 12V wall wart, and then controlling the digipot with a 5V digital signal from the arduino. However, I can only find digipots like this one which looks impossible to solder by hand.

Does anyone have any recommendations on how to do this? Are there other 12V digital pots? Is a totally different approach better?

How many amps? A digipot can't do amps.

Amplify and offset the standard analog output from an arduino.

OpAmps …

And with a pointed enough (but not too pointy) and hot soldering iron and some thin solder, surface mount components like that linked can be easily soldered - once you have a PCB for it that is, are you set up for that? or do you plan on getting a PCB made?

post a data sheet for the motor.

in all probability, you need a simple pwm

Making analog voltages to drive motors is probably not a winning proposition. You'd have the best luck with digipots and a buck or boost supply (as appropriate) - but I'll bet you can just drive the motor with PWM.

Soldering MSOP - it can be done with drag soldering technique, but it's unpleasant enough that I seek other packages (it's a little worse than TSSOP). There are plenty of digipots in other packages.

Well if you want to be able to control voltage from 3.5V to 12V, I can advise you to use LM317 with 240 ohms resistor along with an analog potentiometer of 5k ohms.

You can use this website to calculate your values.

However, to control your motor, you’d better use a full bridge with the PWM as they said before me.

Is there any reason that the arduino has to control the motor, is it part of a system using the arduino?

Tom.... :slight_smile: