Input to lock users out triggered by lightning sensor.
Hi,
I'm presently setting up a KiWiSDR (Ver1) in a site that will not be always attended. As a result, I'm planning to implement a lightning detection system to disconnect or ground the antenna and disconnect from the mains supply in the event lightning is detected. While this arrangement will hopefully make a completely untended system safe, there would be no indication to the user that the antenna is disconnected except for the lack of signals. It would be nice if there was a way to automatically trigger the user lockout feature normally accessed from the control panel with the corresponding message to users. This could perhaps either be a digital input to the KiWiSDR processor or an IP packet. I've looked at the antenna switching extension and there may be some similarity, but I think that works through the control panel, and although accessible remotely, it's not automatic.
Thanks - Steve - VK3SPX
Comments
I've had the same thoughts, and would find this useful...so 2nded!
There are nodered flows out there that watch lighting reports from Blitzortung and shut off a relay when it gets too close. Right now, I do this manually, killing power to my Paradan antenna disconnect when needed via a remote Wifi switch. This grounds the kiwi and disconnects the antenna.
Long term, I want to do this automatically... but the other trick is something to turn it back on... so if you pursue this, I'd love to make sure there's a command/way to turn the Kiwi back to normal mode, too.
-Nate
N8BTR
Hi Nate.
What I have in mind is controlling the disconnect/ground mechanism via a WiFi enabled ESP32 processor or Arduino or similar, connected to a lightning sensor (See https://core-electronics.com.au/gravity-lightning-sensor.html). When lightning is detected, the processor would ground or disconnect the antenna. Perhaps when no lightning has been detected for an hour or so, the antenna connection may be restored. Of course, it would be nice to advise KiWiSDR users of this, hence my suggestion in the original post. Lightning protection is the overriding concern however. I may even go a step further and arrange the disconnected not merely with a relay, but a physical disconnect driven by a linear actuator and push-on type RF connectors to achieve 5cm or so of physical separation. This would result in at least 100kV isolation. This of course would be wasted if the mains supply to the 5 volt dc SDR supply was also not similarly isolated, so this mechanism is also going to need a battery to keep the SDR and the other processor going so connections can be restored as long as the battery doesn't go flat waiting for the lightning to go away.
This is of course a 'longer' term project ! Cheers Steve
I too, have ask jks about adding that capability to the wish list. I use the sparkfun version of that device on an Arduino UNO. It's not perfect, but responds better than I do with a manual disconnect. It is fairly reliable to alarm when lightning is 25 miles or so away.
The first detector I purchased was from Amazon, It worked to some degree but never detects lightning only noise.
I also have the Kiwi option set to disconnect if no users are logged on to the Kiwi. I don't need the antenna connected 24/7.
I agree that the air gap on my relays, does not give me the warm fuzzy that separating the coax by a foot does.
Mike N8OOU 73