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I got this RC car today. It's the cheapest possible model.

I want to make a raspberry Pi project with it (which has its own 5V supply from a power bank).

Is it safe to directly power the motor with the raspberry Pi ? Should I connect a resistance in series first to the motor? If so how much should be the value of the resistance ?

Kind of how we run LED experiments with raspberry ?

Current setup (it came like this) has 3 X 1.5 V AA batteries as input. And it runs pretty fine.

RC car internal circuit board

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  • \$\begingroup\$ We don't know the motor so we can't tell you. Probably, you really shouldn't be driving the motor with a higher voltage than it's rated for. Also, why 9V? That's too high for the Pi, and it seems from your worries also for your motor. \$\endgroup\$
    – Marcus Müller
    Commented Aug 16, 2020 at 9:58
  • \$\begingroup\$ Thanks Marcus, so the pi has its own power supply. Updated the question with this info. \$\endgroup\$
    – Vikash Singh
    Commented Aug 16, 2020 at 10:02
  • \$\begingroup\$ Updated the question, seems like 9V will be too much for the motor. So not risking it. \$\endgroup\$
    – Vikash Singh
    Commented Aug 16, 2020 at 10:21
  • \$\begingroup\$ No, it is definitely not safe or workable to run those directly. Get an FET based H bridge, maybe a TB6612FNG or something newer. Do not use a Darlington part like an L293 or L298, at low voltages you would find it dissapointing. A pi isn't a great fit for this project, it's more of an Arduino / ESP32 kind of role... \$\endgroup\$
    – Chris Stratton
    Commented Aug 16, 2020 at 10:44
  • \$\begingroup\$ If you would prefer something more ready-made, you can get a DC motor HAT for a Raspberry Pi. There are many available, but make sure it will work with your particular model of RPi, and make sure it has enough current capability (I don't know how much current the motors you have would use). \$\endgroup\$
    – Andrew Morton
    Commented Aug 16, 2020 at 12:42

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What ever motor you are using, don't connect it directly to the Raspberry Pi. It is not safe to use them directly with the board. Use a motordriver to connect them. i am saying a motordriver module because, it will be easy to just connect the input and output wires. it is upto you in using a Motordriver module or making your own H bridge circuit. Even simpler boards like Arduino require motor drivers for connecting the motors. This is mainly because the motors draw more current than the board can provide. I am no expert in Raspberry Pi, but using a motor driver with the board will be preferred.

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    \$\begingroup\$ TLDR: An RPi's outputs are completely unsuitable to drive practically any motor. The outputs can just barely drive an LED. In a proper design even for an LED a transistor is used to to the actual switching. Motors take much more current than small LEDs so indeed, using a motor driver is strongly advised. \$\endgroup\$
    – Bimpelrekkie
    Commented Aug 16, 2020 at 14:30

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