Could this project be useful in my case ?

[Mrdindon]

Let me introduce my setup first:
I bought 2 NCB240 (2 apartments), both with NaviLink Lite. Since day one, I have had an issue where, when we take a shower, the Navians randomly stop producing hot water for 30-40 seconds without anyone else using them (I would say roughly once every 5-10 days). I checked for error codes (nothing), and the plumber replaced both water adjustment valves without any success as well. Showers run about 1.6 gallons per minute, which is well over the minimal flow required to trigger the Navians. Unable to clearly identify the issue, I started taking showers with the NaviLink app open to see what was going on. However, as you have probably seen, the refresh rate is quite slow, so I wasn't able to gather any useful information.
That's where I'm wondering if this project could help me because, in the meantime, the plumber asked me to install a webcam in front of the Navian LCD to record what is happening and note the time when the issue occurs. (I haven't done this because I found it a bit wobbly as a solution, even though I have all the infrastructure to do so).
Would this project allow me to capture more information via the RS-485 port with Home Assistant?
What would be the time resolution for the log monitoring?
Thanks! :)

[dacarson]

Wow - sorry to hear about your issue.

Would this project allow me to capture more information via the RS-485 port with Home Assistant?

I am not sure what information is captured with HA. My project captures all data (even unrecognized data) going to and from the Navien and broadcasts it over the home network as a JSON data string. In the Logger directory is a simple python scripts that listens for the broadcast data on the local home network and stores it in an InfluxDB database. It stores it in a format that is useful to access via Grafana. There is also an example Grafana JSON template that can be used to view the information in the same directory.
The data is only broadcast of the local home network, and does not go to the internet.

What would be the time resolution for the log monitoring?

It broadcasts (almost*) every packet of data it sees on the RS-485 port.

*almost. My code does have throttling for identical packets. As in if absolutely nothing has changed in the status information the Navien sent over the RS-485 port to the Navilink, it won't broadcast the repeat data it for up to 5 seconds. If the packet has changed in any way, it will broadcast it. This also applies to command and announce data sent from the NaviLink to the Navien. The 5 seconds is configurable at the top of the NavienBroadcaster.ino file.

As you have two units, and I suspect they are on the same network, you may need to change the broadcast port on one of them so that the listener code can distinguish between the two units. The broadcast port is at the top of the same file. A second listener would be needed listening to a different port, declared in the python listener script at the top.

Let me know if I can help further.