Change display value of signal k paths / deltas

[craig]

Hi,

I have a few paths and deltas that are in different units that I want to display. For example, in SignalK instrument panel, I am using the tanks path for freshwater tank levels, the unit is m3, currently .3m3, but I want to display in litres. How can I run a conversion calculation and set the display to be L? In the instruments panel settings, the only unit is m3.

Also. I have some temperatures that show in Kelvin and need to be converted to C.

Any help or advice, appreciated.

[jim321]

i used nod red to change values and sent those to the node red dash
kelvin to c - 273.15
1 m3 = 1000 liter

[PaddyB]

Might be worth giving the KIP dashboard a go, much better IMHO. Though it still doesn't have conversion from M^3 to L. Signalk works in SI units, then the apps do any conversion afterwards - https://en.wikipedia.org/wiki/Internatio...m_of_Units
The sigK instrument panel has some options, inc temperature, KIP has more >

The KIP author is on here now and again, maybe he'll see this an add M^3=>L conversion

[craig]

Might be worth giving the KIP dashboard a go, much better IMHO. Though it still doesn't have conversion from M^3 to L. Signalk works in SI units, then the apps do any conversion afterwards - https://en.wikipedia.org/wiki/Internatio...m_of_Units
The sigK instrument panel has some options, inc temperature, KIP has more >

The KIP author is on here now and again, maybe he'll see this an add M^3=>L conversion

Cool, I'll give KIP a try, would be a nice feature to have a custom conversion tool for any of the units? I'm happy with the SI units in most cases, but occasionally, a more human readable version is nice for people who are just using the display occasionally and not sure what, for example m3 is, as not a common unit of measurement in everyday life.

Just tried KIP and adding a numeric value, checking the units list, there are units for flow rate in the GUI L/min and so on, but doesn't appear to be just volume units showing up. Am I missing something?

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i used nod red to change values and sent those to the  node red dash
kelvin to c - 273.15
1 m3 = 1000 liter

I'll try Node Red, was trying to keep everything in the GUI as much as possible, so if someone else looked at it when I wasn't available, they wouldn't need to know node red if they needed to troubleshoot. Thanks for your help

[SkipperEarly]

If I recall correct, in OP1 it was possible in the NMEA183 generator to change the SI units into units the user is more familiar with. Somehow I am missing this feature in the signalK server and it makes displaying e.g. temperature or pressure values on the integrated OCPN dashboard rather cumbersome.
Wouldnt the best way be to add a unit conversion option in the signalK plugin "generate NMEA183" ?

[PaddyB]

If I recall correct, in OP1 it was possible in the NMEA183 generator to change the SI units into units the user is more familiar with. Somehow I am missing this feature in the signalK server and it makes displaying e.g. temperature or pressure values on the integrated OCPN dashboard rather cumbersome.
Wouldnt the best way be to add a unit conversion option in the signalK plugin "generate NMEA183" ?

Looking at the code, @signalk/signalk-to-nmea0183 looks like it converts from the signalk SI units into the default NMEA0183 units already. So any unit changing to non standard units might be better done in the display functions. Changing units before could well mess up other things like OpenCPN dash & logbook.

[craig]

i used nod red to change values and sent those to the  node red dash
kelvin to c - 273.15
1 m3 = 1000 liter

I was sending out to a third party system, so ended up using Node Red to pull the data from a SignalK path, run some conversion and then output to the system.

Here's a few examples I ended up with in one of the flows

   

This way I end up not having to use MQTT, but get decent levels of debugging.

I'm integrating a lot of switching and automation into Home Assistant, more girlfriend friendly for lighting, heating and power management control and monitoring. Currently have just over 500 different sensors/entity states in Home Assistant and collecting data from OP2 into HA as well as passing HA sensor data back into OP2