Second subscriber on mobilenet_tflite_data, and does that pipe run in the emulator?

[univault]

We have a small companion process running on a Jetson Orin Nano and are looking
at VOXL 2 as the Blue UAS Framework target. Two questions before we order a board:

1. If we attach a second subscriber to /run/mpa/mobilenet_tflite_data, does that
   disturb voxl-tflite-server or an existing subscriber, or is it a clean fan-out?

2. Does that pipe work in the qrb5165 emulator without the board? If yes, we
   start there this week.

Thanks,
Philip Tran
Univault Technologies LLC

[Sean Hickey]

Hi Philip,

I checked this on a VOXL 2.

1. Adding a second subscriber to /run/mpa/mobilenet_tflite_data is a clean fan-out. The Modal Pipe Architecture creates a separate client connection for each subscriber, so the second subscriber does not consume or steal messages from voxl-tflite-server or from an existing subscriber. I tested this with an existing subscriber already running, then attached another subscriber to mobilenet_tflite_data. The system continued running normally and both consumed messages. See picture below.

Only caveat is normal concerns about load and that a slow subscriber can miss data but won't affect other subscribers/server.

2. The qrb5165 emulator should support the MPA/libmodal-pipe itself. The pipe can still exist without the board. However, mobilenet_tflite_data will not appear in the arb5165 emulator without additional setup. That pipe is published by voxl-tflite-server, which itself consumes a camera input pipe. The emulator does not provider an emulation of the physical VOXL2 camera pipeline by default. For simulation, I would start by testing the subscriber against recorded or synthetic MPA data rather than trying to emulate the full camera pipeline.

Best,
Sean