Servo 3V?

Which servo should I use with microbit? Could you give me the link to the product? (in Amazon, for example)
I’ve tried to use the servo that I use with arduino but it doesn’t work. I suppose it is because the servo needs 5V and microbit gives 3V, right? If I connect the microbit to the computer instead of using batteries it doesn’t work either.


What Make / Model of servo are you using at the moment?

i had this problem some time ago

rather than scour the data sheet for each different make of servo to see if it will work with 3v , i now just wire up external power to the servo as per this guide…

Thank you very much for your answer. I tried it and it does not work. The servo is sm-s2309s (rohs)

Additional power is critical…the common mistake is not sharing the ground. Make sure your battery pack ground is connect to GND and then connect the servo ground (usually brown) to GND. If you only connect the ground side of the pack to ground of the servo…it will not work.

We use SG90 and FS90R servos with no issues.

Occasionally I’ve found a supplier of SG90s or FS90s that work reasonable well at 3V, but eventually they run out of stock or future orders don’t work at 3V.

As @dsssssssss9 and @MrHM said, an external power supply can be helpful (As @MrHM said, sharing a ground with the micro:bit is essential).

If anyone else is interested, I recently made some small printed circuit boards to make it easier to connect servos with external power supplies. The board looks like:

It requires a battery pack, alligator clips (like these:, header pins (like these, and some soldering/glue. The boards make connecting a servo a lot easier.

When assembled they look like:

If made in a small batch (~50), they cost less than $4.50 US each including a cheap servo…but it takes some time and tools to assemble them.


Well done :+1:

Are you planning to release the Gerber files so anyone can get these made up by their favourite PCB manufacturers by any chance ?

@dsssssssss9 Sure — I chose to do them in Fritzing because I was planning on sharing them.

I’ve added the gerbers ( to the repo containing the Fritzing/source files:

I went with jlcpcb. $18.90 + shipping for 100 pcs.


Hi there,

I can share my painful experience. I purchased a brand called FEETECH and it worked like charm (I was able to power it directly from Microbit and via expansion board).

Assuming all servo are the same as long as I get the technical spec right, I went on to purchased a bunch of servos (different brand) and painfully realized it does not work.
After doing some research, I read that many others have the same issue, it appeared most servos only support 4.8-6V but Microbit is 3V. I tested that by connecting the non working brand to Arduino and it worked like charm.

The one that did not work for me is this brand but I presume most Servos don’t work with 3V

The one that work is a brand called FEETECH (you can find it by searching FEETECH on aliexpress).
Coincidentally, I found a note on kritronik that confirmed the above:

In the above link, it stated in the notes:
### Note:
** Although the stated operating voltage for this servo is outside of the the specs for the microbit, we use this servo with the microbit regularly with no issues.*

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