# RC connection/MH carrier directly to VOXL2, while using Flight core V2

Source: https://forum.modalai.com/topic/4108/rc-connection-mh-carrier-directly-to-voxl2-while-using-flight-core-v2
Category: ESCs, Sensors and Accessories (https://forum.modalai.com/category/15/escs-sensors-and-accessories)
Tags: microhard
Posted: 2025-01-21 07:23:12 UTC by Jetson Nano
Replies: 6 · Views: 1523

## Jetson Nano · 2025-01-21 07:23:12 UTC

Hello @Vinny @tom 
I am currently working with Flight Core v2 as the External FC. I would like to know if I could connect the RC(SBus ELRS) to VOXL 2 board , instead of connecting to the FC. Since it is similiar to the connection [here](https://docs.modalai.com/microhard-add-on-manual/), where Microhard modem is used with Cube orange - FC.

## Reply by Eric Katzfey (ModalAI staff) · 2025-01-21 16:48:52 UTC

@Jetson-Nano Which connector would you use for this on VOXL 2? In order to send RC values to PX4 running on an external FC v2 you need to send the RC values in an RC_CHANNELS_OVERRIDE Mavlink message. (https://mavlink.io/en/messages/common.html#RC_CHANNELS_OVERRIDE) So, you would need a custom program on the VOXL 2 to read the input from the RC receiver, create the Mavlink message, and send it to the external FC over the UART.

## Reply by Jetson Nano · 2025-01-22 05:01:38 UTC (in reply to Eric Katzfey)

@Eric-Katzfey thanks for reverting back. can you be little more specific about where to create the custom program and run it. is it inside any servers or externally. 
could guide me with the development.

## Reply by Jetson Nano · 2025-01-22 09:04:37 UTC (in reply to Jetson Nano)

@Eric-Katzfey I'm planning to use the similar case as in Starling 2 Drone. I'm planning to use the J19 port.

![6fa685c8-55d4-4449-9cb6-1bc29911e065-image.png](https://forum.modalai.com/assets/uploads/files/1737536633516-6fa685c8-55d4-4449-9cb6-1bc29911e065-image.png)

## Reply by Eric Katzfey (ModalAI staff) · 2025-01-22 16:28:25 UTC (in reply to Jetson Nano)

@Jetson-Nano I think what you are trying to do is entirely possible. But it isn't anything we have ever tried. So I'm just throwing out some ideas that could maybe help you develop this. Or maybe you have some better ideas. One possibility, that I was referring to above, is to create a new program running on the Linux applications processor. It would have to use the libqrb5165-io library to get access to the UART on J19 that is mapped to the SLPI DSP. Another idea is to actually run PX4 on VOXL 2 and either use `px4-listener` to monitor the input_rc topic or monitor the RC_CHANNELS Mavlink message via voxl-mavlink-server or even voxl-vision-hub and use that to create an RC_CHANNELS_OVERRIDE Mavlink message to send to the external FC. I'm just brainstorming here and can't really provide much more support than offering some high level ideas.

## Reply by Jetson Nano · 2025-01-23 05:23:03 UTC (in reply to Eric Katzfey)

@Eric-Katzfey Thank you for reverting back. I would like to try out the voxl-mavlink-server approach. I had question with regards to that, how will i be able to get the DATA  
(RC_CHANNELS)  from the mavlink-server. Any ideas regarding that. 
@Alex-Kushleyev

## Reply by Eric Katzfey (ModalAI staff) · 2025-01-23 16:51:53 UTC (in reply to Jetson Nano)

@Jetson-Nano Here's some example code: https://gitlab.com/voxl-public/voxl-sdk/services/voxl-vision-hub/-/blob/master/src/autopilot_monitor.c?ref_type=heads#L514