OpenPlotter Signal K APIs: Sending and receiving data using SignalK websocket and HTTP rest APIs.

Last time we learned about Signal K, the heart of OpenPlotter.
But how can you access the data form external sources? Signal K offers APIs for that, e.g. if you want to add own data or if you want to subscribe on data using websocket connections.
It is getting quite technical today but we start with Signal K APIs... NOW!

[@jaysloan289]

I would love to see a video on using no red to send data to signal K. Thanks for sharing!

[@wallisgillwindsensors30]

Let me know if you want to build a low cost high quality NMEA2000 WindSensor to use with OpenCPN/SignalK etc. Cheers!

[@jillesspruyt7003]

Thanks for the video. A question; so get http requests are not possible? Only websockets? After watching your video I am thinking of having hardware switches/buttons connected to a shelly uni which can send http get requests commands. By sending this commands I think it would be possible to show a visual status light in a KiP dasboard, with Single K as source, along with other gauges and meters.

[@Sir-Real]

I was dealing with this question recently, because websockets e.g. via a Raspberry Pico are possible, but not that easy. The REST API is limited as discussed - BUT: You can use TCP and even UDP connections to send data w/o using Websockets. I decided now to use UDP to send some simple sensor data. You need to add a connection in Signal K, UDP with Port, and you can send data quite easy (fire and forget). However, not very safe, nothing you can use if you system is connected to any Internet. But it is something I would love to add to my video as this is a valid way for some systems. If I find time, I will do it ;)

[@michaelpaolini7753]

What IMU board are you using ? Board maker ?

[@Sir-Real]

I am now using the ICM-20948.