Cheap USB to serial adapters / opencpn / NMEA 0183

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Iminei

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If you're getting something through then that tends to suggest it's working. Garbage sounds like an incorrect baud rate - are you sure it's set properly to whatever the NMEA device is putting out?

Pete
 
I think the problem you have is that the UART TTL that these devices output is 5V - 0 0V - 1 IE the opposite polarity to RS232 that NMEA0183 outputs, therefore you either need a USB to RS232 lead or an additional circuit or chip to convert the NMEA from RS232 style to UART style.
 
Iminei said:
Thanks both. The baud rate is correct so I assume it's nrcoyle's answer.
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What are you connecting to? I assumed since you'd chosen a TTL adapter that you were dealing with something like a uBlox GPS that outputs NMEA0183 sentences but over TTL serial. If it's actually a normal NMEA0183 device like a marine GPS or something, then I'm afraid you've bought the wrong thing. A Max232 chip (or a module or adaptor containing one) would fill the gap, but you might be better off just buying an actual USB - RS232 adapter on the first place.

Pete
 
 
Rogershaw said:
You could add a MAX232 chip to the TTL signal to convert the TTL levels to RS232 levels all driven from normal TTL 5V DC supply
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Yes, but if you start with just the bare chip then you also need a few additional capacitors and a means of mounting them; it starts to turn into a little project of its own.

Of course it's all doable, but neater and easier to just get back on eBay or Amazon and order the right thing.

Pete
 
prv said:
Yes, but if you start with just the bare chip then you also need a few additional capacitors and a means of mounting them; it starts to turn into a little project of its own.

Of course it's all doable, but neater and easier to just get back on eBay or Amazon and order the right thing.

Pete
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Oh I agree but The OP did complain of "wasting" 3 GBP so I suggested a way round that.

Or use this

http://www.mikroe.com/add-on-boards/communication/max232/
 
The max232 looks interesting, thanks Roger. But it is a project for another day. Got the correct USB to RS232 cable from the local PC shop and it all sparked into life :)

I don't want to end up relying too heavily on the PC / Laptop Monty - & the VHF needed a GPS input, so one way or another I needed NMEA. A cheap GPS (Garmin 158) connected to the VHF & the PC over NMEA means that the essentials will work without the PC being involved. OpenCPN is now getting GPS from the Garmin, & the Garmin is getting waypoints & routes from the PC. Happy days.
 
Iminei said:
The max232 looks interesting, thanks Roger. But it is a project for another day. Got the correct USB to RS232 cable from the local PC shop and it all sparked into life :)

I don't want to end up relying too heavily on the PC / Laptop Monty - & the VHF needed a GPS input, so one way or another I needed NMEA. A cheap GPS (Garmin 158) connected to the VHF & the PC over NMEA means that the essentials will work without the PC being involved. OpenCPN is now getting GPS from the Garmin, & the Garmin is getting waypoints & routes from the PC. Happy days.
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Hello I have bought an Emtrak R100 to replace my rtl-sdr radio ais Station and would like to set it up through the pc.

Could you tell me what the precise serial to USB NMEA adapter you purchased as I intend to use the receiver specifically on the windows pc as a shore station.

Kind regards
 
Bertonumber1 said:
Hello I have bought an Emtrak R100 to replace my rtl-sdr radio ais Station and would like to set it up through the pc.

Could you tell me what the precise serial to USB NMEA adapter you purchased as I intend to use the receiver specifically on the windows pc as a shore station.

Kind regards
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You're asking a guy who posted 5 years ago ......
 
There's really nothing special about them. Anything with an FTDI or Prolific chip in it should be fine - as should most of the cheap knockoffs, to be honest.

Pete
 
prv said:
There's really nothing special about them. Anything with an FTDI or Prolific chip in it should be fine - as should most of the cheap knockoffs, to be honest.

Pete
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@Refueler and look-see a member who answered from five years ago answered my post too.. Would you believe that :D

Thank you for your kind reply @prv first time setting up a proper AIS . I came across the prolific USB to serial before with a radio cable I once had for a cheap baofeng amateur handheld

I thought the NMEA was a bit more complicated though.
I ordered the board Roger Shaw mentioned above which I think does the same job? Not sure but I'll give it a try.

Cheers again
 
I wasn‘t initially paying too much attention to what you were trying to do, just suggesting USB serial adapters as requested.

Now I’ve looked at your actual intention, I have to ask why you’re looking for an adapter at all given that the R100 has a USB connection already.

Pete
 
Refueler said:
A Polish guy on eBay actually provides USB - NMEA - WiFi combined boards .....

As to my posting - the thread came up at top of list as the other guy had answered ...
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No problem my friend thank you for the reply. I've ordered some kind of board converter the Nmea cable screws into to convert to usb.

Many thanks ?
 
prv said:
I wasn‘t initially paying too much attention to what you were trying to do, just suggesting USB serial adapters as requested.

Now I’ve looked at your actual intention, I have to ask why you’re looking for an adapter at all given that the R100 has a USB connection already.

Pete
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Hi there, hope you are well.
The USB connection doesn't produce any NMEA data, from what I read in the manual... the USB acts solely as a means for 5v power supply (which cannot be connected at the same time along with the NMEA 12v/24v psu simultaneously due to GND issues) the USB is also used to program the device internal settings/ProAIS2.
The AIS data I understand comes from the nmea pins.
Soooo. In a nutshell (I think) I can either power the Receiver by usb and connect the nmea serial wires for the serial data through a converter to the USB.
Or, and this is what I feel is best I can connect the
+ - to my 13.8v psu and connect the serial wires which appears to be the easiest way.

I'm waiting on the converter arriving from the US

Anywho. Thanks again for your patience and all your replies
 
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