Is there a way to access battery voltage data while offline?

Aside from logging into the FloatHub website and viewing the graphs and gauges, is there any other way to access battery voltages from a FloatHub device? For example, does the FloatHub provide this data via NMEA or Signal K or some other programmatic means? It would be nice to be able to see the state of charge of my batteries on my iPad display while sailing or on the hook, for example.

It’s a little more of a challenge than we initially thought as there is very little room left in the device to store web interface elements. Trying to come up with something simple enough that it would fit but still be of some use. Still on the project list; we are happy to prioritize if more users feel they would take advantage of it.

Unfortunately, there is no generally accepted way to transmit voltage status within NMEA-0183, so there’s no format to mark up the data under a specification that other devices would understand. Air temperature, location, and barometric pressure data from FloatHub can be read by other devices (NMEA stream over both local WiFi and Data Out), but not voltages.

It is possible to connect to the serial port on a FloatHub device and switch it from its default NMEA mode to “console mode” by entering the command:


The device will then echo FloatHub data packets on the serial port, which will include human readable values for voltage measurement (V1, V2, C1, C2, etc.)

SignalK would certainly help (as would NMEA-2000), but would swamp the storage and processing capabilities of the device.

We could output “XDR” nmea sentences with our own made up transducer types (V1, V2, C1, etc.), but that would best be done in consultation with developers of navigational software (e.g. OpenCPN) rather than by fiat.

Thanks for the fast response. I had skimmed the NMEA 0183 and didn’t find any sentences related to battery voltage, but had hoped I’d just missed it.

What about the possibility of the FloatHub device offering a simple page via its built-in web server that would allow us to see the state of the device’s various inputs while not connected to the internet?

Thanks again!

That’s an excellent idea, and something we’ve toyed with a little. We do have a rough prototype version of that working, will see if we can’t bump it up the ToDo list a bit.

Awesome, that would be great. I love my FloatHub, but this is the one feature I feel like it’s missing. Let me know if I can help test or anything else.

Yup, will, do. We have a little more testing on that, but should be back in touch to see if you want to beta it in a month or so.

I just returned one of these in favour of your product but it did have a way of transmitting voltage which I think was XDR sentences which could be rendered in WilhelmSK over SignalK or NMEA.

I already run one of these which you could do in parallel which would give you what you need.

The WilhelmSk / SignalK stuff looks very interesting. We may go back to the drawing board on SignalK support.

I don’t know how spendy it is on power compared to CSV/NMEA but JSON runs half the internet these days, maybe more. Just be thankful it’s not XML :wink:

Any movement on the web page display?