Do I need a dedicated serial connection for sending POSE data from a Camera to a Pixhawk

Hardware Companion Computers
1

Hi,

I am building a quadplane that uses an Intel T265 tracking camera to localize the drone. I have a Raspberry PI 3 connected to a Pixhawk via a serial connection (921000 baud). The tracking camera is sending POSE data through the PI to the Pixhawk at 30 hz, additionally, I have a set of Python scripts meant to control the drone autonomously, within the scripts it is continuously requesting telemetry data from the Pixhawk and storing, while also sending command messages to the pixhawk approximately every few seconds. I am worried that the single serial connection will not be able to handle all of this traffic at once without messages getting lost in transmission. Is it worth setting up a dedicated serial connection just for the POSE data and then another for the autonomy scripts, or would a single serial connection be sufficient? If anyone knows this I would appreciate it, or a workaround to synchronize the messages. Thanks!

2

In most cases, 921600 baud is more than enough for a telemetry link. 30Hz pose data and the odd command would use a tiny amount of the 921600.

For example, the VISION_POSITION_ESTIMATE message running at 30Hz will take around 9600 baud, so ~1% of the link bandwidth.

I’m not too sure what you mean by “continuously requesting telemetry data”?

3

Thanks for the reply I appreciate it. By “continuously requesting telemetry data”, I have a script that request position, velocity and a few other sets of data from the Pixhawk, the rate at which I do this can be adjusted, it only effected the accuracy of the python scripts running on the PI.

4

You are using the wrong tool. You should request that needed data be sent at required frequencies automatically, at least for nav data.

1 Like