Icom 802M GPS with Raymarine

[Paul L]

There is more on my Nmea In line to my 802 than just gga, too.

[Redline452]

Originally Posted by SoonerSailor

The M802 must have the $$GPGGA sentence. It doesn't like anything else, unfortunately. The NMEA output of my Raymarine RL70CRC was $$IIGGA, I had to convert it with the programmable MUX to $$GPGGA..

I am feeding my M802 via a Raymarine E85001 Seatalk-to-NMEA interface which outputs $IIGGA amongst several others, without any problem:

$IIGGA,022339,4508.034,N,07316.139,W,2,09,1,28,M,-30,M,1,0000*78
$IIGLL,4508.034,N,07316.139,W,022341,A,D*47
$IIRMC,022341,A,4508.034,N,07316.139,W,0.0,106.0,2 11212,,,D*74

and both the M802 and my Standard Horizon DSC VHF are perfectly happy with that data.

I used the E85001 rather than taking the data from the E120 (nav station) or E80 (cockpit) because the chartplotters are not always on, while the Seatalk bus and GPS are live 24/7. If the E120 does put out the same $II strings, that cannot be the problem. Make sure the MFD is set for 4800 , not 9600 or 38400.

In fact, the above data was captured as I composed this reply, since the E85001 also feeds a mini2440 ARM-based SBC running nmead, which talks to a Bullet 2HP, which I can access from home as the boat is now on the hard for the winter (boating geeks will already know this from the NMEA timestamp and GPS position).

p.s. hello all, been reading a while, just joined

Norman
"Redline"
1998 Jeanneau SO 45.2

[SoonerSailor]

Good to know that $IIGGA works as well as $GPGGA. I thought I had found it did not work, but looks like I'm remembering incorrectly.

Thanks for that info.

[tampahokie]

Originally Posted by SoonerSailor

Good to know that $IIGGA works as well as $GPGGA. I thought I had found it did not work, but looks like I'm remembering incorrectly.

Thanks for that info.

Not to be disagreeable, but I'm not sure you are correct, Sooner. I can specifically confirm that the M-802 will not accept "raw" data from my Raymarine SmartPilot! I have tried to connect the wires 'nine ways to Sunday' and the M-802 will not accept it. According to MacKay Communications in Tampa, the Ray puts out data beginning with $EC and the M-802 needs data beginning with $GP. I haven't ordered myself an E85001 yet, but I'm betting that the E85001 strips or converts the data so the M-802 can read it. Thus, we have the success story Norman wrote about above.

I've also read that some sailors have bought $500 or so multiplexers, such as the Brookhouse to strip the data. I think its rediculous that we have to buy two pieces of equipment plus another piece of equipment just so they can talk. In my case, I bought an ICOM AIS on the same sales ticket as my ICOM M-802 SSB expecting the SSB to read the lat/lon date/time data from the AIS. Oh, nooooo. Same manufacturer and they won't talk to each other. So, I have to spend more money and buy another piece of equipment just to get them to talk.

[SoonerSailor]

Uh, i think I DID say you needed $GPGGA TO work. Someone else said $ECGGA worked.

I tried using a Brookhouse MUX to massage the sentence but gave up and now just use an orphaned handheld GPS on ship power to feed NMEA to the radios. Nice thing about that is I can have all the other nav gear off but still have GPS data going to the radios at the cost of just a few milliamps.

Chip

[Redline452]

Hi and Happy New Year all, just back from a week in the sun (on an all-inclusive beach, unfortunately not a boat as I was outvoted by the rest of the family, but in the sun and warm nonetheless).

I can only repeat that my M802 is happy with $IIGGA, so definitely not limited to $GPGGA. Given that, I would expect it to accept most anything else between the $ and GGA, such as EC, as it would be very odd to have coded it to accept GP and II specifically. Not impossible, but unlikely.

Re the problem with using the 500 AIS as a source, I expect it's the volume of data, not the extra sentences, which cause the problem. AIS streams can easily overwhelm a 4800 bit/sec link, which is why most or all receivers run at 38,400 b/s. The 802, like most radios, definitely wants 4800, and you can't connect a firehose to a straw. Any radio would have that problem.

I brought my 802 home for the winter with the intention of trying some WINMOR and Weatherfax decoding, so if I can find a couple spare hours I will try generating a few NMEA sentences in Hyperterminal (or PuTTY) and seeing if GP, II or EC does make any difference. No promise, but it'd be an interesting experiment.

[tampahokie]

I pinged Icom to ask what prefixes the M-802 will accept. Waiting for a reply. If you figure it out first, please post.

[tampahokie]

Originally Posted by SoonerSailor

I tried using a Brookhouse MUX to massage the sentence but gave up.

Do you have a Brookhouse Mux for sale?

[SoonerSailor]

The MUX has plenty of other duties even now. It streamlines AIS data into GPS and Wind data from the SeaTalk network to feed the Nav station laptop, and it uses the GPS data from the handheld (which feeds the radios) as a backup GPS source in case the SeaTalk GPS data stops coming in. So not for sale.

[Redline452]

I just ran a set of tests with PC feeding my M802 at 4800 8N1

$GPGGA works. So does $IIGGA, and even $GIGGA, $HIGGA, $XXGGA

GLL and RMC by themselves do NOT work, it only seems to accept GGA, but it does not care about the Talker ID (first two characters).

Hope this helps.

[Redline452]

oh, and upon re-reading the thread, I can also confirm that $ECGGA works fine on my M802.

$ECGGA,012339,4500.034,N,07316.139,W,2,09,1,28,M,-30,M,1,0000*75

(and my thanks to NMEA MTK checksum calculator for a convenient lazy man's way to calculate NMEA checksums in test messages).

[tampahokie]

Quick update ... I received my new Brookhouse iMux and installed. Using data from Icom MA 500-TR AIS and Raymarine SeaTalk, I STILL can't get lat/lon/time on my M-802 or VHF. Wout at Brookhouse says I need to provide the GPS data from a puck antenna directly to the iMux. So, the puck antenna is on order.

In the meantime, the iMux definitely works as advertised ... at least as far as my iPad is concerned. I bought iNavX program from Apple for around $50. The iMux wire-lessly sends all data to my iPad everywhere on the 40' sailboat. I have yet to get laptop PC working on WiFi (and the SSB/VHF issue is still out there), but so far so good. More to follow. Thanks to all who helped!

[richardhula]

Originally Posted by tampahokie

Quick update ... I received my new Brookhouse iMux and installed. Using data from Icom MA 500-TR AIS and Raymarine SeaTalk, I STILL can't get lat/lon/time on my M-802 or VHF. Wout at Brookhouse says I need to provide the GPS data from a puck antenna directly to the iMux. So, the puck antenna is on order.

In the meantime, the iMux definitely works as advertised ... at least as far as my iPad is concerned. I bought iNavX program from Apple for around $50. The iMux wire-lessly sends all data to my iPad everywhere on the 40' sailboat. I have yet to get laptop PC working on WiFi (and the SSB/VHF issue is still out there), but so far so good. More to follow. Thanks to all who helped!

Suggest checking the following:

1) Are you sure the BNC input plug is wired correctly with no short between outer shell and centre pin.

2) Is the NMEA 0183 feed at 4800 baud?

3) Can you check using PC with HyperTerminal or similar monitoring prog that the stream includes the GGA sentence, and that this sentence contains valid position data. The sixth field in the sentence should be set at 1 or 2. If its 0 that indicates no fix.

Note the two character talker identifier prefix is almost certainly gated out so not relevant.

[twistedtree]

And some say NMEA 2000 is complicated and hard to debug...........

[tampahokie]

My system is up and running ...

Raymarine ST-60 instruments, Smart Pilot computer, Icom AIS and M802, Standard Horizon VHF all connected through Brookhouse iMux. And, the iMux broadcasts WiFi to iPad running iNavX. GPS antenna connected to iMux is primary source of lat/lon/time data for radios and iMux data output via WiFi. Really cool to have data on iPad. Using iPad as repeater, only, but it can be set up to be a controller.