# Does voxl support Retractable Landing Gear

Source: https://forum.modalai.com/topic/127/does-voxl-support-retractable-landing-gear
Category: General Questions (https://forum.modalai.com/category/2/general-questions)
Posted: 2021-02-05 17:16:44 UTC by Davide Miccone
Replies: 5 · Views: 870

## Davide Miccone · 2021-02-05 17:16:44 UTC

Hello,
I use a Tarot landing gear controller (https://www.flyingtech.co.uk/electronics/tarot-retractable-landing-gear-controller-tl8x002). How can I configure VOXL to manage it?
Thank you

## Reply by modaltb (ModalAI staff) · 2021-02-05 17:54:06 UTC

Hi  @Davide-Miccone,

Looks like that has a PWM/servo input?  Are you looking at the VOXL or VOXL Flight?  VOXL Flight has the 8 channel PWM output, for a standard quad, we've tested with AUX RC passthrough for gimbal control which could likely work.  VOXL standalone doesn't have PWM output but has other interfaces that could drive a PWM device likely.

## Reply by Aldo Castro Freire · 2021-02-06 21:56:50 UTC

Hi yeah I run into the same problem, I wanted to use the i2c port  using pca9865, but voxl does not have any practical i2c port application.

So what you can do is use another microcontroller and control it using gpio from voxl.   

Note: voxl flight does have a pwm but it is used for the motors in my case. So it is being used by  the autopilot so there is no way of using it for me

## Reply by modaltb (ModalAI staff) · 2021-02-06 22:23:13 UTC

@Aldo-Castro-Freire , this is a pretty easy to use application for using  the I2C port(s) -->
https://gitlab.com/voxl-public/core-libs/libvoxl_io/-/blob/master/lib/apps/voxl-i2c.c

There's a good write up here for that as well: https://docs.modalai.com/voxl-i2c-io/

## Reply by Aldo Castro Freire · 2021-02-06 22:30:05 UTC

Yes, that is there but is a low level logic  control. If I want to use any device that requieres an implementation it will take some time to control a device such as pca9865, it is easier to use a microcontroller as an atmega32u that has the libraries.
In my opinion, it is not worth it to have to rewrite the whole library for voxl. It will take me so much time.

## Reply by Chad Sweet (ModalAI staff) · 2021-02-06 22:46:55 UTC

I think you mean you would prefer that VOXL supports PCA9865 natively. 

We have an I/O library ready to go, [libvoxl_io](https://gitlab.com/voxl-public/core-libs/libvoxl_io/-/tree/master). [voxl-i2c](https://docs.modalai.com/voxl-i2c-io/) is an application that is an example of using libvoxl_io for i2c commands.

One would need to implement the PCA9865 i2c protocol using libvoxl_io to control that part externally from VOXL.

As mentioned previously, Flight Core has native PWM support if you were to send over MAVLink