CR2032 3v battery to Arduino Nano 16Mhz?

Projects General Guidance
1

Hi!

I want to create a really simple school project where I connect an arduino nano to the qwiic haptic motor and make it vibrate every so often. I would like to power it with a single CR2032 button battery since its needs to be compact. Is it okay to simply connect the battery to the 3v3 pin? I don't need the circuit to be on for long, its purely for a 'feels like' prototype and would be happy to regularly switch out batteries for the amount of time I would be using it.

Keen to learn why it would/wouldn't work.

Thanks!

2

Oops! Your link does not go to the technical information about your haptic motor. Without the current and voltage requirements, you question cannot be answered.

3

Thanks for pointing that out! Please see below for the relevant data sheets:

Motor

Screenshot 2022-11-12 at 18.05.56
Screenshot 2022-11-12 at 18.05.561086×288 55.5 KB

if I am right, the voltage needed would be 2.3v approx for the motor

Driver

  • i have no ideas where to start with the driver...
4

If you mean connecting the CR2032 to the 3.3V pin of the Nano, with the intention of powering the Nano from that, then definitely NO. That is a fairly low current voltage output, not an input.
You would be better off using a Pro Mini running at 8MHz, that can be run without a voltage regulator, and the clock frequency is within specs at the voltage you want to use.

5

The motor voltage/current are not relevant to your system. They are ALL generated and controlled by the driver. What I do not see is any reference to the maximum current drawn by that driver. So, I guess it try it and see.

6

ah I see! So from my understanding, the 3v3 pin is used to pass 3v3 to the driver/motor and cannot be used in reverse to power the actual microcontroller? To power that, I can only use the Vin pin, not the 5v or the 3v3? Thanks for the recommendation, i'll look into that board!

7

okay, I will do! thanks for explaining that to me :slight_smile:

8

You can run the Nano with 3V to the 5V input but you should, technically, run the processor at 8 MHz instead of 16 MHz. With an ISP device, you can set the processor fuses to use the internal 8 MHz RC oscillator instead of the 16 MHz crystal/resonator.

I recommend the "USBasp" device. They are quite inexpensive. make sure you have a 10-pin to 6-pin cable adapter for it.

In ancient times the AVR processor evaluation boards used a 10-pin connector for programming. Five of those pins were Ground. The Arduino eliminated four of the Ground pins and uses a smaller 6-pin connector.

9

Amazing, thanks for explain all of that to me and for the recommendation!

10

Have you considered to use a 8MHz / 3.3V ProMini for your project?