Page 1 of 9 123456 ... LastLast
Results 1 to 10 of 83
  1. #1
    Join Date
    Jun 2011
    Location
    Volos-Athens
    Posts
    4,663

    Question anchor chain counter to NMEA0183 Garmin proprietary sentences via arduino?

    hello all,

    almost managed to fit the whole idea in the subject line

    I've checked various diy electronics projects presented here and it seems to me that what I'm thinking is doable and wonder if someone has already done.

    Plan is to:
    • get a magnet/sensor set on the gypsy of my Lofrans tigress windlass
    • get the up or down signal from the windlass controller (so that I know if I'm counting up or down the revs...)
    • wire them to the digital and analogue inputs respectively of an arduino uno I have lying around
    • output the custom NMEA0183 sentences that AutoAnchor built to support/communicate their 601 black box to marine nav equipment
    • wire that to a GMI10 through the 7pin NMEA0183 comms cable (yes I know it's a NMEA2K gauge, but it does support the old standard as well)
    • view that on the f/b and lower helm GMIs on my boat.



    I understand that not many ppl have GMI10s or 20s, but considering that the AutoAnchor 601 costs almost 1000usd, the cheapest non NMEA chain counter is 300+, the magnet sensor is 30euro and the uno another 20 or so, I recon it's worth a shot

    So Qs:

    anyone has done it?
    any reason it wont work (am I missing something?)
    For the time being, you'd still need the normal windlass toggle switch to operate the windlass.

    cheers

    V.

  2. #2
    Join Date
    Nov 2009
    Location
    Southampton
    Posts
    35,232

    Default Re: anchor chain counter to NMEA0183 Garmin proprietary sentences via arduino?

    Do you know whether the Garmin display understands oddball non-standard chain-counting sentences on its NMEA0183 input? My gut feeling is that it's unlikely...

    Also I suspect the up/down "signal" will simply be a couple of 12v lines hence digital input rather than analogue, but that's easier if anything. Possibly will need some kind of anti-spike protection as well as the obvious downshifting to 5v / 3.3v.

    Pete
    Last edited by prv; 09-11-15 at 22:41.

  3. #3
    Join Date
    Jun 2011
    Location
    Volos-Athens
    Posts
    4,663

    Default Re: anchor chain counter to NMEA0183 Garmin proprietary sentences via arduino?

    Quote Originally Posted by prv View Post
    Do you know whether the Garmin display understands oddball non-standard chain-counting sentences on its NMEA0183 input? My gut feeling is that it's unlikely...

    Also I suspect the up/down "signal" will simply be a couple of 12v lines hence digital input rather than analogue, but that's easier if anything. Possibly will need some kind of anti-spike protection as well as the obvious downshifting to 5v / 3.3v.

    Pete
    The whole point of the project is that AutoAnchor 601 clearly states support for GMI10. It is also mentioned in the GMI firmware updates somewhere (don't have the time to check right now) Having said that, I've not managed to trace this page on my GMIs but I've not worked hard on that.
    Basically again from the AA601 manual it does send two sentences, one is the identifier of the device, the other is the rode specs/data/state/length/whatever.
    So I'll simply try and duplicate that. True, in all NMEA standards I've checked, there's no mention of these sentences, but there's explicit mention of Proprietary sentences (starting with a PO** iirc)

    Correct on the digital vs analogue, thanks and also on the anti-spike.
    I do have a couple of leftover 33V -> 5V transformers from my VIMAR USB sockets project, so no issues on that, 1.5A should be plenty for a arduino uno doing bugger all and just sending serial sentences.

    Ideally I'd hope that the GMI screen would use the buttons to send other custom messages to the AA601 which would mean I could have the GMI fully controlling the windlass, but i'll have to see how that works.
    I've yet to find anyone that has AA601 to ask a few qs. Keep in mind though that AA601 is a black box, no user interface, so got to have the GMI as a front end. If things look quieter over the w/e I'll try to establish what's going on.

    cheers

    V.

  4. #4
    Join Date
    Nov 2009
    Location
    Southampton
    Posts
    35,232

    Default Re: anchor chain counter to NMEA0183 Garmin proprietary sentences via arduino?

    Quote Originally Posted by vas View Post
    The whole point of the project is that AutoAnchor 601 clearly states support for GMI10. It is also mentioned in the GMI firmware updates somewhere
    Great, sounds like a goer then

    Quote Originally Posted by vas View Post
    Correct on the digital vs analogue, thanks and also on the anti-spike.
    I do have a couple of leftover 33V -> 5V transformers from my VIMAR USB sockets project, so no issues on that, 1.5A should be plenty for a arduino uno doing bugger all and just sending serial sentences.
    I didn't mean a stepdown for the power supply, though of course you'll need that too. I meant for the lines you'll be running from the solenoid box to digital inputs on the Arduino. I assume those aren't allowed to be over 5v, but the current drawn will be practically nil. Probably just a suitable resistor would do the job? My analogue electronics knowledge is pretty shakey though

    Pete

  5. #5
    Join Date
    Apr 2006
    Location
    Portsmouth, UK
    Posts
    2,889

    Default Re: anchor chain counter to NMEA0183 Garmin proprietary sentences via arduino?

    It looks like Garmin added the AutoAnchor 601 sentences to it's NMEA0183 vocabulary at version 3.20
    http://www8.garmin.com/support/downl...ls.jsp?id=4819

    A little article here showing the GMI20 AutoAnchor screen..
    http://www.panbo.com/archives/2013/0...ses_found.html

    It should be quite easy to re-create those sentences since AutoAnchor have published their sentence information here
    http://www.autoanchor.co.nz/sites/de...ge_Formats.pdf
    I do have a GMI10 display on board but am rather busy at the moment trying to build the Arduino Autopilot. The last NMEA 0183 work I did was on the PIC18F (thanks to Angus' YAPP project) so can't say how easy it is on Arduino.

  6. #6
    Join Date
    Jun 2011
    Location
    Volos-Athens
    Posts
    4,663

    Default Re: anchor chain counter to NMEA0183 Garmin proprietary sentences via arduino?

    thanks for gathering and posting all the relevant links
    Will do some tests with dummy values and see how it goes.

    BTW, there is some interest in the mobo forum, and some work already done on this, so we may have to join the powers so to speak and see what we get.
    Arduino autopilot sounds interesting, care to elaborate?

    cheers

    V.

  7. #7
    Join Date
    Jun 2013
    Location
    Hopefully somewhere warm
    Posts
    9,103

    Default Re: anchor chain counter to NMEA0183 Garmin proprietary sentences via arduino?

    Quote Originally Posted by vas View Post
    thanks for gathering and posting all the relevant links
    Will do some tests with dummy values and see how it goes.

    BTW, there is some interest in the mobo forum, and some work already done on this, so we may have to join the powers so to speak and see what we get.
    Arduino autopilot sounds interesting, care to elaborate?

    cheers

    V.
    Couple things you probably know already...

    One of the many available of these seem to work well to get to/from NMEA , on one extra of the hardware serial ports an arduino mega has anyway, sorts out the voltages and inverts the logic. -
    http://www.ebay.co.uk/itm/High-Quali...YAAMXQLw1R3NRX

    Also, nmea sentences have a checksum at the end which you will need to calculate if you change the datatype or making from scratch, the subroutine below calculates it. Strip the "$" from the start of the string and everything from and including the "*" at the end, the add them in again with the checksum at the end. .
    Hope that makes sense.


    char checkSum(String theseChars) {
    char check = 0;
    // iterate over the string, XOR each byte with the total sum:
    for (int c = 0; c < theseChars.length(); c++) {
    check = char(check ^ theseChars.charAt(c));
    }
    // return the result
    return check;
    }
    Last edited by GHA; 10-11-15 at 16:05.

  8. #8
    Join Date
    Jun 2011
    Location
    Volos-Athens
    Posts
    4,663

    Default Re: anchor chain counter to NMEA0183 Garmin proprietary sentences via arduino?

    sorry, late in replying..

    thanks for the checksum code, imported it on my test code, but need to test it on the GMI during the w/e. Curious if I got it right though as I need to grab a few "correct" NMEA0183 messages for test purposes.

    Not sure I understand why I need the serial port as the uno has the Tx and Rx ports and I'm not going to use it for anything else... No idea of voltages that NMEA expects, will check.

    I asked Hurricane who has already worked a lot on this topic, to start a thread on the mobo forum. Would be nice to keep the discussion together.

    cheers

    V.

  9. #9
    Join Date
    Jan 2011
    Location
    Worcester, UK
    Posts
    1,315

    Default Re: anchor chain counter to NMEA0183 Garmin proprietary sentences via arduino?

    Of course you could be really clever and get the arduino to read the depth, and tidal state and prediction (not quite sure where from?) and calculate the required scope :-)

  10. #10
    Join Date
    Jun 2011
    Location
    Volos-Athens
    Posts
    4,663

    Default Re: anchor chain counter to NMEA0183 Garmin proprietary sentences via arduino?

    Quote Originally Posted by skyflyer View Post
    Of course you could be really clever and get the arduino to read the depth, and tidal state and prediction (not quite sure where from?) and calculate the required scope :-)
    in the Med you don't need tidal state/tables, so yes, if we can "trace" depth info from the NMEA bus, and we combine with wind instrument data, we could recommend a scope
    It is getting rather silly though
    another idea is that we could use the same arduino board with a few more inputs and wire a couple of flow sensors and get instant consumption figures. Apparently flow sensors are around 200usd a pop, but the black box that does the calcs and sends the NMEA sentences are approx 800usd

    Anyway, I'll be moving these ideas to the other thread in the mobo section

    cheers

    V.

Page 1 of 9 123456 ... LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Latest YBW News

Find Boats For Sale

to
to