# How to use PCA9685 with voxl

Source: https://forum.modalai.com/topic/432/how-to-use-pca9685-with-voxl
Category: Flight Core and Legacy VOXL (https://forum.modalai.com/category/9/flight-core-and-legacy-voxl)
Tags: voxl-flight
Posted: 2021-09-08 04:46:52 UTC by SWARNA MOHAN CHANDRA KANTH
Replies: 1 · Views: 822

## SWARNA MOHAN CHANDRA KANTH · 2021-09-08 04:46:52 UTC

Hi we have voxl flight controller i.e inspired flight (IF1000). we are planning to control servo in main PWM outputs but we are not successful. after that, we are planning to use PCA9685 to voxl flight core. how to integrate PCA9685 to voxl is there any manual or wiki is there, if yes please send links.

thank you in advance

## Reply by modaltb (ModalAI staff) · 2021-09-09 12:39:27 UTC

@SWARNA-MOHAN-CHANDRA-KANTH said in [How to use PCA9685 with voxl](/post/2092):
> PCA9685

Seems like that is an I2C device, you could start looking here at how to control an I2C bus from VOXL: 

https://docs.modalai.com/voxl-i2c-io/

How are you looking to control this and for what use case?  Above assumes you are running the I2C program on the VOXL's processor (not PX4).

If using PX4, you'd want to do this in the PX4 firmware instead.