Radar does not stop

[rszemeti]

I have Radar_pi controlling a Garmin xHD radar works mostly OK, but one annoyance is when closing OpenCPN it does not send a stop message to the radar.


Apparently the developers were under the impression that radars would stop if the application didn't "Ping" them, but this is not the case.


Someone suggested "Tony's (Antipole) plugin "JavaScript " ,,, but then provided no other clues as to how this would help.


Any ideas? I'd just like to shut the radar down when I close OpenCPN and save a bit of battery if no one is looking at it and I accidentally leave it powered on ...

[Hakan]

I suppose a Garmin MFD has a relay controlling pin 5 on the IP cable. To run such a radar scanner with OCPN we use a manual switch to power it up-down. I think you have to remember the switch or in some way make a similar function with a RPi and GPIO.
A Navico radar scanner need a "ping" but apparently not Garmin.

[rszemeti]

There is I think, a bit of code in the plugin that can turn the radar off and on, because there is a graphical button that does that ... there is also a section of plugin code that can be run when the plugin closes, so I think it just needs a call in that section to the "turn the radar off" code ...


I did ask about this on GitHub they said the reason it was not done was in case someone else was on your boat and also using the radar and it would go off when you closed your OpenCpn which would be an inconvenience for this other person, but I only have one OpenCPN display so its not an issue for me. Or there could be a checkbox maybe for boats with mutliple displays.

[Hakan]

Could be. If that command exist or not for the Garmin scanner I don't know. But there would be a reason for Garmin to use a hardware switch?

Let's see if someone having worked with the Garmin code shows up.

[rszemeti]

There is definintley a command, the start stop button activates and stops the scanner just fine. It does stop the scanner motor but obviously leaves the magentron heaters on so the radar is in "standby" not "warmin up"


I guess the best solution would be something that toggled a GPIO pin when you pressed "start" on the radar, that way it would not waste power until you actually wanted the radar ... when you press stop the scanner stops, but if it is not used for maybe 5 minutes, the GPIO pin goes low and the radar fully shuts down ... or when you close OpenCPN the GPIO pin goes low and the radar goes back to sleep.

[Hakan]

If you can arrange a RPi script to control the power on/off switch I think others may be fond of a report.

Good luck.

[rszemeti]

I think it would have to be integrated into the plugin rather than a separate script as such, but there may be some advantages in simply registering a script with the plugin as an event handler, then users coudl add whatever they liked in the script I guess.


I am determined to get OpenCPN/SignalK/py_pilot working how I want it this year ... some stuff I already fixed, I released a SignalK plugin to work with the popular JBD BMS used in many lithium battery packs over bluetooth, that is working well for me, but I suspect it needs some more work. Py_pilot pretty much works, I spent too many hours trying to figure out the bug with the display of compass reference points in the calibration display, it's still not clear to me why the axes flip after you change tabs, but, I tried.