Battery powered ATtiny85 + DC motor power consumption

Discussion in 'Power Electronics' started by awwwt, Mar 5, 2017.

  1. awwwt

    Thread Starter Member

    Aug 24, 2015

    I am using a simple ATtiny85 micro controller to power a small DC motor that is rated around 3 volts. To control the motor am setting its pin on the ATtiny to high when I want it to turn on, and low to turn it off. I am powering the ATtiny with a single 3v 20mm coin cell (CR2032).

    When I power the motor with the battery without the microcontroller, it runs at a very high RPM and is powerful, however on controlling the motor through the ATtiny it becomes much, much weaker. The ATtiny outputs 40ma per pin, however when I power the whole thing through a USB, the motor works great. I’m sure that the ATtiny can’t be using up that much current from the battery that it would be that significant? Sorry if I am being a total noob here!

    I was wondering if anyone could suggest a good way of making the most of my 3v battery power, to power the ATtiny and give the motor the highest amount of current possible. I have been looking into using a MOSFET transistor but not sure if this is the correct option? And if it is, I'm not sure of the best spec one to get, as I'm used to using higher power ones.

    Any help much, much appreciated. Thanks so much :^)
  2. AlbertHall

    AAC Fanatic!

    Jun 4, 2014
    awwwt likes this.
  3. awwwt

    Thread Starter Member

    Aug 24, 2015
    Thanks so much. So if I was going to power the Arduino with no less than 3 volts, would this one, with Threshold Voltage Vgs of 2.1 be okay?

    I am quite unsure of the parameters with MOSFETS as there are so many - for example, what is the difference between Drain Source Voltage Vds)', 'Rds(on) Test Voltage (Vgs)' and 'Threshold Voltage (Vgs)'?

    Thank you!