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  Lightning Detector
Posted by: longjohn119 - 03-07-2018, 02:41 AM - Forum: General discussion - Replies (8)

Has anyone tried to interface one of those AS3935 lightning detector devices to Open Plotter/Signal K? 

I've been using them with Arduinos but since they can communicate via SPI or I2C I don't see any reason you couldn't interface with a Raspi or even make a wireless module with an ESP32 although the libraries I have are for Arduino (Tested and 2 devices functional) and a python script for the Raspi. (I haven't tested it yet) They basically send a warning signal, number of strikes and approximate distance although they seem to try to track the distance to the storm's front edge rather than the distance of the actual strike which technically is better because that's where the closest potential for lightning would be. Max distance is 40 km or 25 miles although I've checked mine against some online lightning maps and got hits a little further than that

If not would anyone be interested in something like that? It should be easy to set it up to trigger a warning and send to a dashboard to log strikes and distance. I could document it if there is interest although I can't guarantee when exactly I'd finish it but likely before May or June

A couple of places that sell them are

http://www.playingwithfusion.com/product...hp?pdid=22   Playing With Fusion

http://www.embeddedadventures.com/as3935...-1016.html    Embedded Adventures <----- This is the one I've used

  Waterproof displays
Posted by: mxtommy - 03-06-2018, 03:58 PM - Forum: General discussion - Replies (7)


I've asked before but maybe there are new developments. Smile Is anyone aware of an affordable waterproof sunlight readble display that would be suited for putting in the cockpit? Smile I know that's kind of asking for it all (usually it's a pick 2 of the 3, affordable/waterproof/sunlight readable) but I'm hoping the prices are coming down.

For what it's worth the best I've found so far are from Faytech. (US Prices here: https://www.faytech.us/touchscreen-monitor/industrial/ )

Granted the prices are a bunch better then I've found elsewhere, but would like to see what others have found (If anything)


  Issue converting GPS from Signal K to NMEA0183
Posted by: Lucas_A - 03-05-2018, 04:56 AM - Forum: How do I...? - Replies (1)

Hi everybody,

I am back with another question!  Big Grin

So far I have been able to use different components (such as BNO055 IMU) on an Arduino then on OpenPlotter. It works like a charm and to give you the different steps, here is how it works:

- Get raw data on the Arduino Mega from sensors
- Data is sent with Signal K format from the Arduino to Raspberry Pi (USB)
- A short Python program get the Serial data and transfer it to Signal K server
- On OpenPlotter, I get this data (via Signal K diagnostic) and I convert it to NMEA0183 thanks to the NMEA0183 Converter
- I then get this data on OpenCPN or QtVlm or Instumental Panel of Signal K server

Issue is when it comes to GPS signal. I cannot get the Signal K sentences to be read by the NMEA0183 Converter when the data sent is not a number. Is it normal?

To give you an example, to write NMEA sentences such as $...RMC or $...GCA , you have to indicate "N" (North) or "S" (South) when it comes to the GPS direction. But if I write letters "N" or "S" in my Signal K sentences, it is not recognized by the NMEA0183 Converter and it does not see it in the available Signal K data...

I tried "-1" and "1" instead but it does not work either..

It can seem silly to use the Arduino to convert NMEA0183 to Signal K and then OpenPlotter to the opposite but the idea is to use the Arduino as a hub to centralize all data from sensors. 

Plus, unless I am missing something, by connecting the GPS directly to the Raspberry, I loose the benefit of having GPS data on the Signal K server...

Thank you for your help!


  Navman wind 3100s no nmea to OP
Posted by: cepicscepics - 03-03-2018, 02:31 PM - Forum: How do I...? - Replies (3)

Hi, I just installed an used wind instrument on boat, I would like to send the nmea0183 sentence (IIMWV and IIVPW) to Openplotter is it possible?

Nmea out from wind instrument to A+ and ground to B+ of the serial/USB adaptor

In the nmea tab I selected the USB1, 4800 baud, apply change, restart but no sentences on inspector. I also tried to applying filters to IN sentences but no joy

Op 8.0



  Cellular data for cruising boat?
Posted by: PaddyB - 03-02-2018, 08:55 AM - Forum: General discussion - Replies (6)

This looks quite interesting for uploading data and smaller downloads >


$49 plus $5 for the sim - looks like it should work most places we would sail to. 
$0.60 per Mb so no youtube streaming but for daily grib forecasts it could work out very reasonable, so no more running around for a new local data sim when you get to a new country.
I'll give it a go anyway, would be really handy  for monitoring when away from the boat with data coming from a mobile phone at the moment.

  OP 17.1A, and signalK not starting
Posted by: Havnjero - 03-02-2018, 06:21 AM - Forum: General discussion - Replies (5)

have updated recently and signalK isn't happy. I'm not able to start SK or find the mapcache folder.
I have also tried unsuccessfully to add my boats mmsi to the marinetrafficreporter file.
have found nothing online related to error 111 as it is in this particular instance.

Signal K starting
[Errno 111] Connection refused
marinetrafficreporter: mmsi missing in settings
signalk-server running at

Cannot open NGT-1-A device /dev/ttyOP_N2K

Error reading /home/pi/.openplotter/public/mapcache

is there someone out there whom can help me to shed a little more light on this?

  Project Solutions board ?
Posted by: affinite - 02-27-2018, 06:17 AM - Forum: General discussion - Replies (15)

I have learned a lot by following and searching other peoples posts on here. - Thanks to all

I've also learned a lot by looking at other forums eg NodeRed, Letscontrolit and of course good old "Google".

I know that the "Brag Board" and "How do I" forums are intended to offer a chance to share that knowledge but I wonder if it would make sense to include a slightly different structure so that in addition to being able to post a "How do I do that" question we also have a way to post "This is how I did that"

For example I am now beginning to feel that I have an OP system which works pretty well. In addition to the core OP stuff (which I dont have the skills to contribute to directly) I have configured wireless ESP8226 senders which measure battery voltages,  tank levels, and environmental  data and sends it all as MQTT over wireless NodeRed. I have done lots of reading and experimenting to get to this point (which has been fun) but I cant help but feel that if Id been able to read someones "How I did that" notes it would have helped.
I dont want to post my experiences in a Brag Board post as I dont think Im ready to "Brag" about my setup but I would happily post some notes under a topic of "Tank level measurement options" for example

Have I just got too much time on my hands or is this worth a try ?  Big Grin

  [SOLVED] Function Node Code to correct non-linear sensor ?
Posted by: affinite - 02-25-2018, 06:23 PM - Forum: Node Red - Replies (11)

I am reading my fuel/waste/fresh water tank levels using the original resistive senders (0-190 Ohm) configured in a voltage divider.
The output voltage is then read by an ADS1115 ADC connected to an ESP8226 wireless sender running ESPEasy firmware. The ESP8226 sends the data as MQTT over WiFi and is picked up in NodeRed for presentation on my dashboard on the Pi. (All shamelessly copied from others on here Smile

All works just great but I'd like to incorporate some correction for the non-linear nature of the sender.
In OP I know there is the option to do this for a directly connected ADC but not one sending data over MQTT
In the ESPEasy firmware there is the option for "2 point correction" but I need more plots in the curve than just "1024 = full and 0= empty".

I think that what I really need is some JSON code for a NodeRed function node that will take a raw ADC value range and convert it into a value in litres. 
I'd want a small table of 8 such conversions as the sender has 8 or maybe 10 steps.

for example
ADC in        value out
0-99           0
100-299      20
300-499      50
500-699      100
700-799      200
800-999      250
1020+        320

I have no clue how to write JSON code so Im hoping that someone may have addressed this issue before.

  Analog Spped/Depth (and maybe more)
Posted by: JurgenP - 02-24-2018, 04:43 AM - Forum: How do I...? - No Replies

First of all, if this has been addressed I'm sorry, please feel free to direct me to the right place.
I did a couple of searches on these boards but I couldn't find anything. 

I'm currently in the process of rewiring my sailboat, and integrating all the navigational data available.
Currently the (old) chartplotter only gets data from the GPS antenna. 

The general idea is that I want all data to be both available at the chart table as well as in the cockpit. 
So the RPi3 is the one that will need to do the heavy lifting at the chart table, assisted by a Shipmodul Miniplex-2USB to gather and sort out the data.

The issue that I'm pondering at the moment (there are many others, which light get addressed here later):
There is an analog log (simple peddling wheel) and a 150khz depth sounder that returns an analog signal to a NASA Marine Clipper Duet display, which is mounted next to the compagnonway, in the cockpit. The Duet does not produce any NMEA output.

In order to fix this, I see a couple of possible solutions each with its drawbacks. 

1) The NasaMarine Clipper Log provides NMEA0183 output sentences ($VWVHW / $VWVLW), so is I could find a unit that took the 150Khz signal from the echosounder displayed it and provided NMEA0183 output for it .... The NasaMarine Depth does provide output in a propriety format, and an arduino sketch exists to convert it to NMEA standard.
Disadvantage: cost (2 new displays) and modifying the layout of the available displaying in the cockpit.
2) Get an Actisense DST-2-150 module (Ebay) that takes the signals for both and outputs NMEA0183 sentenses for both. And replace the duet by a unit that displays that NMEA data.
Disavantage: cost of the actisense module and the NMEA repeater display.

I was wondering if the signals could be intercepted (before they hit any display) by either an arduino (cheap, versatile) or the RPi (already present) and if that device could be used to convert the signals to NMEA0183 output.
After that the signal could be send to a NMEA repeater display in the cockpit. Or (even better), if the signal doesn't get affected (too much) by tapping into it send the original signal to the exiting Nasa Marine Clipper Duet. 

Anyone any experience with something like this, or any ideas?


  how do I clone micro-sd cards?
Posted by: adriaan - 02-23-2018, 01:42 PM - Forum: How do I...? - Replies (10)

I have OpenPlotter installed on a RPi, updated en upgraded to the latest version.
That took some time. A backup with a cloned sd-card seemd to be timesaving.

I have tried this and lost a few micro-sd cards.
This is what  I did:
First I find out the name of the device (the sc-card with the fully installed OpenPloter) with fdisk -l
Next I unmount the device
Then I make the image (sudo dd if=/dev/sdb of=~/Documents/openplotter.img)
Then copy the image to a blank micro-sd card (sudo dd if=Documents/openplotter.img of=path-to-the-sdcard (usulally also /dv/sdb))

That should be it, I think. But I never succeeded in getting this card to boot. The best I achieved was getting the colourfull startup screen.

Whar do I do wrong?

Then I start all over.
I wipe the contents  of de card with fdisk -d, make a new partition (fdisk -n), make it bootable (fdisk -a) and create a vfat filesystem (fdisk -t, then choose b).
Then umount and issue the command: sudo mkfs.vfat /dev/sdb.
Often an error occurs. I then have a card which cannot be mounted. Sometimes I can rescue the card by creating a new mountpoint (in the terminal or with "Disk").
But sometimes the card is invisible when I insert it.
I now have 2 sd cards in this state. I must have done something wrong. I would very much like to know what that is.