About high voltage servo


I’m about to use high voltage servos.
Is NAVIO+ able to support driving it?
Would there be any voltage problem regarding the PWM output for the servo?

Thank you for the answer!


Hi Peter,

Navio+ will output PWM, but please separate Navio+ power and servo power. Navio+ will source power from the servo rail, so if you supply more than 5.25V to it you can damage Raspberry Pi. For HV servos use something like a powerbox.

Hi ivereninov:

Sorry that I have another question.
I am using NAVIO+ for larger helicopters which require high voltage servo and motor.
The BEC output is also 6V or 8V which is higher than 5.25V.
Since my NAVIO+ and RPi are powered through the BEC by one of the servo rail, such BEC voltage should also be reduced to be no higher than 5.25V?




Are you using a power module? If so then you can just leave the servo rail unpowered. If you do not use a power module and power Navio+ through the servo rail voltage has to be under 5.25V.

If you post a more detailed description of your projected setup I can check it for any mistakes.

Dear ivereninov:

Thank you for your kindness!
Currently I would like to use NAVIO+ to operate for a larger-scale helicopter which uses 6S (22.2V) battery to supply for motor and servos.
All of the servo inputs and BEC output are all from 6V to 8.4V, which are beyond 5.25V.
According to your description, I need a powerbox to raise the output PWM signal to, e.g., 7.4V with extra power supply to drive the high voltage servo.
But since I use BEC output to supply the power to the whole system via servo rail before, the current BEC output cannot be connected to the servo rail, right? since it is high voltage.

So could you please let me know how I can setup with extra equipment so that NAVIO+ can be used in a high voltage servo and BEC environment?
I would be very appreciated, and if possible, can you suggest the device names that I need in order to have a safe setup?

Thank you very much!



There is no need to step up PWM signal, it is 5V and all servos (including HV) are fine with it. We want to power them separately. I did a quick search on available devices, basically we are looking for something that will allow powering Navio+ servo rail and your servos from different voltages. Cheap and basic option or expensive with many features. This should be enough to power your servos and protect Navio+.

Now we need to power Navio+, a 5V source is needed. Any 5V 2 A BEC will do the job.

Hi ivereninov:

Thanks for your explanation!

So this means that I use an extra powerbox to convert the PWM output to high voltage and supply the power of servos externally through that powerbox, right?
Then how about the motor? Since the motor is connected with the BEC, and the input of the BEC is also high voltage, that means I also need to convert the PWM output which is connected to the BEC to high voltage through powerbox, and then the motor can also be controlled?
In this case, since all servos and motors are externally powered, can I use a USB power source to power the NAVO+ and RPi with the mini USB interface?

Thank you!


Thank you for a quality product. your power module says " Supports LiPo batteries up to 4S". I am building a Large Quad-copter for long range and have it designed at 6S. Will your power module handle 6s? will it power the Pi and navio+ or will the voltage coming out of the power module be too high. How can I get the stats on the power usage?


Hello David,

The power module can handle 6S, but it will cause too large voltage for ADC on current and voltage measurement pins. So if you remove those pins from the connector you will be able to power Navio+ from 6S, but will have no data about voltage or current.

how can I get the data on voltage and current?

That should work: