Help with RS232 to TTL conversion for NMEA0183

[skyflyer]

use 3,3v as supply to the 3232 - it works fine.

Probably teaching granny to suck eggs etc, but the diagram i posted earlier of the 3232 circuit is not the direct pinout as the pin numbers have been moved all over the place!

I only have single line 0183 kit, so my ground is common to everything, so i have just the NMEA (depth) input to pin 13, the gps input to pin 8 and the output from the Due back to pin 11.

Its working fine for me now for the 0183 side of things - the Due multiplexes GPS and Depth, works out from analog data the windspeed and direction and creates an 0183 sentence for that, multiplexes that and outputs all 3 sets of data to my plotter. The single 3232 chip, running on 3.3v does all the logic and voltage conversion (like Angus said it would ages ago but I wash't listening - sorry!)

I had problems with some N2k stuff getting sent through on the 0183 side of things but the following statement cured that:-

NMEA2000.EnableForward(false); // Disable all msg forwarding to USB (=Serial)

But at the moment I'm having trouble getting anything out of the Canbus transceiver that can be read by the N2K side of things! It world with Actisense reader on PC but not with real instrument!

 

[vas]

thanks, will try it then, just wondering how I fried this 3232 board...

regarding the N2K to plotter, what plotter are you using and how have you wired them together? Did you simply chop a drop cable and wired it to the can bus, that's what I've done and it works.

Wonder if your plotter is too fussy and wont accept signals that are not identifying properly the device. I'm saying that as my GMI10 wont recognise the Due-canchip as a N2K device (although I've added the headers that Timo recommends)
Did you try any dummy code from Timo's NMEA2000 master lib such as the WindMonitor? Does that work on the plotter? Today I'll try hooking the GPSMAP751 and the 4008 to the due and see if they also get the data.


cheers

V.

 

[skyflyer]

thanks, will try it then, just wondering how I fried this 3232 board...

regarding the N2K to plotter, what plotter are you using and how have you wired them together? Did you simply chop a drop cable and wired it to the can bus, that's what I've done and it works.

Wonder if your plotter is too fussy and wont accept signals that are not identifying properly the device. I'm saying that as my GMI10 wont recognise the Due-canchip as a N2K device (although I've added the headers that Timo recommends)
Did you try any dummy code from Timo's NMEA2000 master lib such as the WindMonitor? Does that work on the plotter? Today I'll try hooking the GPSMAP751 and the 4008 to the due and see if they also get the data.


cheers

V.

Ah, sorry for confusion, my plotter is 0183. The N2K requirement is for my new a/pilot so i can get wind and SOG info to it (as a minimum).

i think I have found the problem, I had this line commented out (not sure what) so will try later with it 'live'

// NMEA2000.ParseMessages();

edited to add:
The actual wiring a did as per thesis cehmatic, if you need more detail I can supply but hopefully you get the idea?

https://www.dropbox.com/s/9gan6ecmuvthhk1/N2Krig.pdf?dl=0

 

[vas]

Ah, sorry for confusion, my plotter is 0183. The N2K requirement is for my new a/pilot so i can get wind and SOG info to it (as a minimum).

i think I have found the problem, I had this line commented out (not sure what) so will try later with it 'live'

// NMEA2000.ParseMessages();

edited to add:
The actual wiring a did as per thesis cehmatic, if you need more detail I can supply but hopefully you get the idea?

https://www.dropbox.com/s/9gan6ecmuvthhk1/N2Krig.pdf?dl=0

yep, wont go very far without
NMEA2000.ParseMessages();
in the loop!

Yes, diagram looks bog standard, bet it's the ParseMessages.

Still need to find out why my Due works sends all sorts of PGNs to the bus, are read by GMI10 but it's not listed as a N2K device...

cheers

V.