<![CDATA[Telemetry interfering with UART?]]>I have a custom module running with modified PX4 firmware on the FlightCore. It uses the UART on J4 to receive data from a custom sensor board. This has been working for over a year.

In default.cmake I comment out TEL3:/dev/ttyS1 so that I can use it for my sensor board.

We had previously used the RFD900 with the FlightCore for updating some parameters, but since we are an underwater system we had removed it a long time ago to save power.

For an upcoming customer demo in the field I was asked to install the RFD900 so that during testing the system could be removed from the water and verified to still be operational without opening up the system.

I have been having intermittent issues with getting data from my custom sensor board whenever the radio is connected. After a very short time the topic stops publishing and using listener I just see stale data. The data is also being published to the datalog and I see the data stop, while other data from the system continues to log.

I thought maybe this was a power issue, so instead of powering my sensor board from the 5V on the J4 connector I am powering directly from the battery, but am still seeing the issue.

As far as I can tell, no one else is using ttyS1. Is there an issue with having high data bandwidth on both ttyS1 and ttyS6 (UART7 on J5) that would kill my connection?

]]>https://forum.modalai.com/topic/1911/telemetry-interfering-with-uartRSS for NodeMon, 12 Oct 2026 00:02:30 GMTMon, 06 Mar 2023 15:00:51 GMT60<![CDATA[Reply to Telemetry interfering with UART? on Mon, 06 Mar 2023 21:08:19 GMT]]>I have discovered that the entire module seems to stop. I had been assuming it was the UART that was failing. Is there some PX4 setting where when a telemetry link occurs that something would stop/pause running modules?

]]>https://forum.modalai.com/post/8857https://forum.modalai.com/post/8857Mon, 06 Mar 2023 21:08:19 GMT<![CDATA[Reply to Telemetry interfering with UART? on Mon, 06 Mar 2023 15:44:26 GMT]]>When I stream the data in the terminal by launching the module manually, connected via USB to QGC, I see the stream. I then plug my base station radio in, and as soon as it gives me a blinking red light the data stream stops.

I am using RFD900x radios in a multi-radio network. Previously when I tested these radios I was using RFD900+ in a single set.

]]>https://forum.modalai.com/post/8843https://forum.modalai.com/post/8843Mon, 06 Mar 2023 15:44:26 GMT<![CDATA[Reply to Telemetry interfering with UART? on Mon, 06 Mar 2023 15:30:14 GMT]]>I set the module to no longer run in the background. When I use MAVLink Console to launch the module and the base station radio is disconnected (but not the radio connected to the FlightCore) I can run the module and it runs fine.

When I have the radio link connected and I use MAVLink Console to launch the module I get an error in trying to configure the port.

a9c76b74-2f54-4af5-a02b-17a287ebb871-image.png

]]>https://forum.modalai.com/post/8841https://forum.modalai.com/post/8841Mon, 06 Mar 2023 15:30:14 GMT