[ethancheez]

CCSDS sometimes works, sometimes doesn't work. I wasn't able to figure it out. Though I didn't spend too much time to debug. Switched over to ComFprime for now which I confirmed works consistently.

[nathancheek]

Hi @ethancheez, I dug into the CCSDS problem while working on #29. It looks like there were 3 problems causing this:

First, ComQueue depth of 3. The LED sends an LedState event at 10 Hz, and EventManager pushes events straight into ComQueue, causing a 3-deep queue to fill up. With ComFprime, events are dropped silently (my testing showed 5 of 22 OpCodeCompleted events dropped in 5d9fc78). With ComCcsds, a full queue makes comStatusIn assert, which could make the board run for a few seconds and then stop. I haven't seen any drops or asserts at depth 10, with either ComFprime or ComCcsds.

Second, a TaskRunner::addTask insertion-sort bug, fixed later in fprime-community/fprime-baremetal#42. It looked like comQueue could fall out of the task table and never run, meaning nothing downlinking.

Third, the ComCcsds aggregator timeout wasn't connected. Since fprime 4.1, ComCcsds aggregates packets into 1 KB frames and only sends one when it fills, unless aggregator.timeout is called. Without this connection, downlink lagged or stalled when traffic was light.

#29 covers the same upgrade (4.0.0 sync -> 4.1.1 -> v4 project layout -> 4.4.0), updated in lockstep with fprime-community/fprime-arduino-deployment-cookiecutter#12, and includes fixes for all three issues. It uses CCSDS from 4.4.0 onwards. 4.1.1 stays on F' framing because its fprime-baremetal pin doesn't have the fprime-community/fprime-baremetal#42 fix. I tested it on Pi Pico and Teensy 4.0. I also included two things from your branch: the v4 project layout (with a matching deployment_namespace option in the cookiecutter) and removing the stale InvalidBlinkArgument line from the docs.

Once the submodules in #29 have been approved (so that we can point to the approved commit hashes), would you be okay with merging #29 (and fprime-community/fprime-arduino-deployment-cookiecutter#12) and closing this one and fprime-community/fprime-arduino-deployment-cookiecutter#11?

[ethancheez]

Closing because #29 has been merged to main.