Nmea3Wifi and ST70i

Discussion and support for the Nmea3Wifi multiplexer - a 2-input Nmea 0183 wifi multiplexer with a full bidirectional SeaTalk1 input/output port.
0ff
Posts: 8
Joined: Fri May 26, 2023 8:43 am

Re: Nmea3Wifi and ST70i

Post by 0ff » Sun Jun 04, 2023 6:50 pm

Hi dagnall,

as confirmed by PM, the position was actually correct before and it's broken with Firmware Alternate Minutes orderST58.zip.
As for the SATs display: this seems to work perfectly now, when I take the GPS inside, it goes down to 2-5 and when I go outside it goes up to 12 - so I'd call this working fine.

I'll test this version a bit more tomorrow (just leave it running) and report if I find something weird.
Thanks again!

dagnall
Posts: 458
Joined: Wed Mar 04, 2020 6:36 pm

Re: Nmea3Wifi and ST70i

Post by dagnall » Sun Jun 04, 2023 9:20 pm

Fabian,
MANY THANKS for testing the code again!
It is much appreciated! I cannot understand why the 16 bit conversion seems different in this Datagram.. but you have confirmed that this IS correct! (also - I have confirmed that our earlier ST58>NMEA conversion uses the same data configuration.. )

My most recent version is now here:
It has some corrections in the alternate debug display that stops a crash during debug (!)
But also has the "correct" ST58.
Last edited by dagnall on Mon Jun 05, 2023 8:47 am, edited 1 time in total.

0ff
Posts: 8
Joined: Fri May 26, 2023 8:43 am

Re: Nmea3Wifi and ST70i

Post by 0ff » Mon Jun 05, 2023 8:24 am

Hi dagnall,

I'm not sure if this was intended, but the version you've attached is showing up as "Experimental CODE (CAUTION) Ver 2.02 Jun 2 2023 20:32:37" (so from last Friday) - is that really the latest version?

Thanks for checking!

dagnall
Posts: 458
Joined: Wed Mar 04, 2020 6:36 pm

Re: Nmea3Wifi and ST70i

Post by dagnall » Mon Jun 05, 2023 8:46 am

NO!..
That was not my intention!.. MANY thanks!!
I was tidying and must have sent the wrong one..
Before I complete my tests: I have added a GGA>datagrams 54,57,58 conversion.

I think this probably removes the need to convert RMC or GLL > (optionally) 50/51 or 58.

I will keep the "use datagram58" option present for now- but it may disappear in future!,
I am assuming your GPS sends GGA?

Datagram58 when "received" will generate a GLL.

D

0ff
Posts: 8
Joined: Fri May 26, 2023 8:43 am

Re: Nmea3Wifi and ST70i

Post by 0ff » Mon Jun 05, 2023 8:55 am

No worries!

Yes, my GPS sends GGA:
0ff wrote:
Sun Jun 04, 2023 9:20 am
The is the TCP Output of the NMEA3Wifi so I guess yes, the GPS does send those: (Note I've removed the GPS position from the logs, I guess if someone sees the images above they can figure it out anyways, but I'd rather not have it in text here)
Did you upload the latest version already or are you still working on that? (Just wanted to make sure I didn't miss it).

Thanks!

dagnall
Posts: 458
Joined: Wed Mar 04, 2020 6:36 pm

Re: Nmea3Wifi and ST70i

Post by dagnall » Mon Jun 05, 2023 10:45 am

0ff wrote:
Mon Jun 05, 2023 8:24 am
Hi dagnall,
I'm not sure if this was intended, but the version you've attached is showing up as "Experimental CODE (CAUTION) Ver 2.02 Jun 2 2023 20:32:37" (so from last Friday) - is that really the latest version?
Thanks for checking!
I THINK.. ( I have been known to be wrong! ;) :oops: ) this is now much better:
Candidate CODE Ver 2.08 Jun 5 2023 11:42:14
NMEA3.ino.zip
Candidate CODE Ver 2.08 Jun 5 2023 11:42:14
(669 KiB) Downloaded 165 times
Changes include some very small fixes in the debug mode so that ST57 displays when it is received, and I have added NMEA GGA > SeaTalk datagrams 54,57 and 58 conversions.
I have retained (for now) the optional conversion to datagram58 in RMC and GLL. (when it replaces datagrams 50 and 51).

- OF NOTE- The GPS I have been using for testing is a very simple 'blox NEO-6M'. This turns out NOT to send any COG in RMC. (at least when stationary on my desk!) . Which has caused confusion to me during these tests as our NMEA3 Seatalk to NMEA "RMC" is actually triggered by COG.
I do get SOG all the time.. so I may need to consider triggering the RMC send on SOG reception. But that can wait. :)

As ever.. please try it and let me know about any bugs or errors you find!
D

0ff
Posts: 8
Joined: Fri May 26, 2023 8:43 am

Re: Nmea3Wifi and ST70i

Post by 0ff » Tue Jun 06, 2023 7:46 am

"Much better" does not even come close to describing this version - it's outstanding!

Yesterday, I did a little road-testing with the new version, so that I could actually test everything in-motion. (In the car, not on a boat, but the Nmea3Wifi doesn't know that :D)
The conversion works flawlessly, both for speed and for the COG (at least with my GPS) - even when stationary (after moving) it stays locked at exactly the angle I'd expect.

Honestly, this version would probably be fine to use on a boat. Very, very good job! Thank you!

Of course some new kinks came up with a "kind-of-a-real-world test" like that. Still, I want to stress how unimportant they are - it's just that your project is so near to perfection for my use-case, that I want to make sure to tell you about them so you can decide if you want to pursue them or not :)
  1. (Easy fix, low impact) The number of SATs is actually not correct (anymore?) When comparing the output of the ST70i I can see the number decreasing with better visibility of the sky now. I've compared that to the Raw NMEA output and it seems at some point you are inverting the number (so it goes down with more sats reported from the GPS). I'm not sure if you changed something here, but I believe this was correct earlier. (Never checked it against the raw NMEA before, so I'm not sure actually).
  2. (Not-so-easy fix, low impact) On startup, the Nmea3Wifi will send out Seatalk messages indicating a GPS position of 00°00.000' until the GPS has a fix. I believe a better way would be to not send out ST58 until the GPS reports a fix. Is that possible? (This is only a problem in combination with #4 though, so not sure if fixing it is worthwhile)
  3. (Not-so-easy fix, lowest impact) When the GPS signal is lost (I drove through a tunnel and from experience that doesn't really happen with boats where I sail), instead of the Display sounding the GPS alarm, it will go to showing LAT 00°00.000' and LNG 00°00.XXX' (where XXX was around 030 - so almost, but not quite, 000). This is most probably not a problem at sea, where GPS visibility shouldn't be a problem, ever. Just noticed it.
  4. (Hard fix, I fear, possibly high impact) Unfortunately I am now able to reproduce a bug that I believe is originating deep in your network code. I'm not even 100% sure it can be fixed completely to be honest. The problem shows up when the "system" (i.e. the Nmea3Wifi, GPS and the Display) is fully up and in working condition. I then connect my tablet via wifi to the Nmea3Wifi and then I connect to the TCP port I've setup to output the NMEA datagrams. (I need it to be TCP for being able to control the Autopilot later, I believe UDP would not have the problem). Now everything works great, I get the data, I can see it on the display, awesome. Now my tablet goes to sleep / decides to change wifi / runs out of battery and in turn disconnects from the Nmea3Wifi' wifi network (thus closing the TCP connection). This sends the Nmea3Wifi into a hard crash it seems - the display stops updating, after a few seconds the GPS alarm sounds, and it will not restore itself until I remove power and reboot it. (Pressing the reset button also works, of course). I fear this might be a real problem, because actually when sailing I don't want my phone or tablet's display to be turned on all the time, just when I need it. And at least my phone will, in this case, shutdown wifi after a few minutes - which would trigger this bug 100% of the time :(
Please let me know if you need more information on any of those, as I said I now have a way to get the NMEA data from the GPS interpreted so I can actually compare what it sends with what the display shows up. So if you need any details, just tell me.

Again: Thank you so much for your amazing support and dedication!

dagnall
Posts: 458
Joined: Wed Mar 04, 2020 6:36 pm

Re: Nmea3Wifi and ST70i

Post by dagnall » Tue Jun 06, 2023 8:35 am

Fabian
Many thanks for the encouragement and bug reports. I will PM you later with some more details, (mainly about #4) but for anyone else following this thread… We will explore these issues and try to resolve them soon.
Dagnall.

Post Reply