<p>This has likely been answered here: <a href="https://drones.stackexchange.com/a/230/50">https://drones.stackexchange.com/a/230/50</a>, but to paraphrase:</p>

<p>A standard flight controller can easily be set up to control a servo, as per your edit.</p>

<p>You first need to plug in your flight controller (with props off, if you’re using one with motors already attached) and enable ’servo tilt’ in the configuration tab, then go into the CLI.</p>

<p>You then need to type ‘resource’ (assuming you are on the latest version of Betaflight.)</p>

<p>As you want a tricopter and your flight controller is likely for a quadcopter at least, you can reassign a motor output (or any other PDB with a built-in timed) to become a servo output. If you don’t know how to re-map resources in Betaflight, the answer I have linked gives an excellent rundown.</p>

<p>You should then see a servo tab appear in Betaflight, and from there you should be able to configure everything you need.</p>

CC BY-SA 4.0
2020-04-22T21:36:11.980Z
Is 3.3v from the FC pads enough to trigger servo PWM trigger?
ifconfig
CC BY-SA 4.0
2020-04-22T21:37:42.510Z
@ifconfig I’m not too familiar with servos, but I’d imagine it depends on what servo OP is using. If not then the flight controller probably has a 5 or 9V BEC, or they can run a separate BEC directly from VBAT.
Drones and Whatnot
CC BY-SA 4.0
2020-04-22T21:38:49.880Z
Well, in that case you'd need to employ an external MOSFET or BJT something like that to switch 5v from 3.3v, no?
ifconfig
CC BY-SA 4.0
2020-04-22T21:40:17.450Z
@ifconfig like I say, I’m not too familiar with servos - as far as I know they have a V input, a gnd and a pwm input, so I thought you can power the servo from any voltage pad powerful enough
Drones and Whatnot
CC BY-SA 4.0
2020-04-22T21:42:29.767Z
Right, but most all switchable FC pads are driven to 3.3v. Only Buzzer+/- is 5v, but I'm not sure if it is usable for servos. Anyway, this is a fairly nuanced topic, especially because we have few hardware specifics.
ifconfig
CC BY-SA 4.0
2020-04-22T21:44:47.030Z
@ifconfig true - knowing more about OP’s FC and servos would be helpful
Drones and Whatnot
CC BY-SA 4.0
2020-04-22T22:37:11.047Z
@ifconfig it is possible to remap buzzer for other applications but it doesn't have the timer functionality (as far as I know), so most probably it's not possible to use as a servo pad.
Nikita Pedorich
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2020-04-22T22:55:04.177Z
@NikitaPedorich Yeah, that's what I thought might be the case.
ifconfig
CC BY-SA 4.0
2022-07-18T15:58:08.123Z
The short answer is yes it will work, but may be slow/behave slightly strangely. The long answer is: you should be using a digital servo anyways, which will definitely trigger on 3v3. That also allows you to up your PWM frequency to something more responsive. David Windestal has lots of information on this
Brydon Gibson
CC BY-SA 4.0
2020-04-22T21:31:38.533Z
2020-04-22T22:34:21.740Z
2020-04-22T22:34:21.740Z
Drones and Whatnot
<p>Is there any way to set up a servo with full control for a tricopter using a normal flight controller and normal drone parts? Are there any other things that I should use or consider?</p>

<p>This servo will be used to roll the rear motor (there will be two front motors). The prop size will probably be around 6-7'' so the servo will require a decent bit of power. </p>

<p>Essentially, I'm asking if a servo can be powered from a flight controller (does the flight controller have the ability to output 3a 5v) and can I control the servo? Are there only specific flight controllers that can output that?</p>

CC BY-SA 4.0
2020-04-22T20:35:15.457Z
Not sure there's enough context here. How will this servo be used and how is your tricopter going to be built/what is it going to look like?
ifconfig
CC BY-SA 4.0
2020-04-22T20:42:59.187Z
@ifconfig I edited it to provide more clarification.
Jacob B
<servo><tricopter>
How to drive a servo for a tricopter with a flight controller?
Jacob B
# How to drive a servo for a tricopter with a flight controller?

(Asked by: username_0 on 2020-04-22)

Is there any way to set up a servo with full control for a tricopter using a normal flight controller and normal drone parts? Are there any other things that I should use or consider?

This servo will be used to roll the rear motor (there will be two front motors). The prop size will probably be around 6-7'' so the servo will require a decent bit of power.

Essentially, I'm asking if a servo can be powered from a flight controller (does the flight controller have the ability to output 3a 5v) and can I control the servo? Are there only specific flight controllers that can output that?

**Tags:** servo, tricopter

> **Comments:**
> **username_1**: Not sure there's enough context here. How will this servo be used and how is your tricopter going to be built/what is it going to look like?  
> **username_0**: @username_1 I edited it to provide more clarification.  

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## 1 answers

### Answer by username_2 on 2020-04-22. Score: 4 | Accepted answer

This has likely been answered here: <https://drones.stackexchange.com/a/230/50>, but to paraphrase:

A standard flight controller can easily be set up to control a servo, as per your edit.

You first need to plug in your flight controller (with props off, if you’re using one with motors already attached) and enable ’servo tilt’ in the configuration tab, then go into the CLI.

You then need to type ‘resource’ (assuming you are on the latest version of Betaflight.)

As you want a tricopter and your flight controller is likely for a quadcopter at least, you can reassign a motor output (or any other PDB with a built-in timed) to become a servo output. If you don’t know how to re-map resources in Betaflight, the answer I have linked gives an excellent rundown.

You should then see a servo tab appear in Betaflight, and from there you should be able to configure everything you need.

> **Comments:**
> **username_1**: Is 3.3v from the FC pads enough to trigger servo PWM trigger?  
> **username_2**: @username_1 I’m not too familiar with servos, but I’d imagine it depends on what servo OP is using. If not then the flight controller probably has a 5 or 9V BEC, or they can run a separate BEC directly from VBAT.  
> **username_1**: Well, in that case you'd need to employ an external MOSFET or BJT something like that to switch 5v from 3.3v, no?  
> **username_2**: @username_1 like I say, I’m not too familiar with servos - as far as I know they have a V input, a gnd and a pwm input, so I thought you can power the servo from any voltage pad powerful enough  
> **username_1**: Right, but most all switchable FC pads are driven to 3.3v. Only Buzzer+/- is 5v, but I'm not sure if it is usable for servos. Anyway, this is a fairly nuanced topic, especially because we have few hardware specifics.  
> **username_2**: @username_1 true - knowing more about OP’s FC and servos would be helpful  
> **username_3**: @username_1 it is possible to remap buzzer for other applications but it doesn't have the timer functionality (as far as I know), so most probably it's not possible to use as a servo pad.  
> **username_1**: @NikitaPedorich Yeah, that's what I thought might be the case.  
> **username_4**: The short answer is yes it will work, but may be slow/behave slightly strangely. The long answer is: you should be using a digital servo anyways, which will definitely trigger on 3v3. That also allows you to up your PWM frequency to something more responsive. David Windestal has lots of information on this  

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