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Openplotter serial output
#1
Hi

I'm  still experimenting with the openplotter serial outputs using the pi gpio

i've connected a gps on the gpio serial input using the adafruit tutorial (see my previous post)

Now i'm trying to connect my PC to the gpio serial output ( I use specific navigation software on my PC which cannot use nmea over tcp)
The hardware is simple: an ftdi usb to serial converted connected to GPIO TX end 0
It actually works with openplotter nmea inspector running but stalls if i pause or stop the inspector
any idea's how to fix this
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#2
How do you set this connection on OpenPlotter? I assume you have created a serial output in the NMEA 0183 multiplexer, what is the port? /dev/ttyAMA0?

I do not understand what is the rol of the inspector here
  Reply
#3
hi

I create a serial connection  /dev/ttyS0  ,set the baudrate, as an output in open plotter, after that i make a physical link to my PC (from the PI GPIO TX pin  via  an optocoupler to a serial to usb converter to the pc usb port)
After that I open the usb serial port in open cpn for example

the output from this connection is erratic but becomes completely stable when i start the nmea inspector
I've no explanation for this behaviour

NB on a Pi3 /dev/ttyS0  = /dev/ttyAM0 on a Pi2
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#4
Use a USB serial ttl converter instead of the internal uart1 of the RPi 3. It's a known RPi 3 problem.
As you already recogniced, if there is enough processor usage (inspector) all things are fine. But if the processor change to lower speed (energy saving) the baudrate drops.
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#5
hi
if i use the usb port i cannot connect the pi directly to my PC, except with a usb a-a cable (dangerous), or a usb transfer cable (no experience).
The only hardware solution i can think of is using 2 usb to serial connectors and connecting them with an opto coupler.

pi >> usb to serial >>Tx >>> opto >>> Rx >>usb to serial >> pc
  Reply
#6
great contribution e-sailing, you have saved us lot of time and tests
  Reply
#7
Big Grin 
hi

thx e-sailing, the problem is solved now
My serial uart output is working as it should do  (if you want a schematic just let me know)

I've used the solution in the link you gave in the previous post  [Image: biggrin.png][Image: biggrin.png]
Code:
/boot/config.txt
, add the line
Code:
core_freq=250
. Save and reboot! The GPIO UART now operates at the correct baud rate, and is available at
Code:
/dev/ttyS0
, and NOT
Code:
/dev/ttyAMA0
  Reply
#8
hi
another possible solution, without cables.
I also use as navigation software another software: Oziexplorer on Windows XP, it will only use COM ports for GPS and AIS signals. Now I also want use all openplotter services but the main navigation software remains Oziexplorer.
I solved using VSPE Virtual Serial Port Emulator (free software)
http://www.eterlogic.com/Products.VSPE.html
It allows you to send AIS and GPS input data from com ports to Oziexplorer and simultaneously via TCP to Openplotter, or the NMEA data from Openplotter via TCP can send them to Oziexplorer on the COM port. With it you can build in Windows any data exchange
Hello
Renato
  Reply
#9
hi

thx for the information
The vspe tcp to serial software did not work on my 32 bits windows 10 PC
fortunately i found http://www.netburner.com/learn/how-to-cr...erial-port
which works on my 32 bits machine
I will try this for a while, if it proves unstable i will use the serial output again
  Reply
#10
(04-25-2016, 05:53 AM)Renato Wrote: hi
another possible solution, without cables.
I also use as navigation software another software: Oziexplorer on Windows XP, it will only use COM ports for GPS and AIS signals. Now I also want use all openplotter services but the main navigation software remains Oziexplorer.
I solved using VSPE Virtual Serial Port Emulator (free software)
http://www.eterlogic.com/Products.VSPE.html
It allows you to send AIS and GPS input data from com ports to Oziexplorer and simultaneously via TCP to Openplotter, or the NMEA data from Openplotter via TCP can send them to Oziexplorer on the COM port. With it you can build in Windows any data exchange
Hello


Hi Renato,
I’m also a big fan of Oziexplorer and want to run it wirelessly on my PC off RPi OpenPlotter (which is also great). 
 
I’ve got RPi OpenPlotter working (including a boat AP) and my boat feeds it Navdata at 4800 and AIS (38400) and OpenCPN also works great.  I can see also all this data over wifi on my iPad running iNavX (which is really good for AIS collision avoidance from the cockpit).
 
Please would you explain in more detail how you set up the virtual COM ports to work between OpenPlotter and Ozi?  As far as I’ve always understood it, Ozi likes to receive position data and AIS data on different ports.  I’m familiar with the Ozi configuration process using real (serial) or virtual COM ports with USB cables.  I’ve never tried to use Ozi “over wifi” but I understand the VSPE generally.
 
I may have a misconception but I thought OpenPlotter multiplexed all the incoming NMEA streams and presented them at address 127.0.0.1 and port 10110 at 38400 baud; the highest speed. 
 
Can Ozi cope with “unscrambling” this combined data feed or do you set up OpenPlotter to forward the NMEA streams separately (and 2 VSPEs)?
 
Many thanks
Andrew
 
PS The RPi guys screwed up the UART with the Bluetooth facility in the Pi3.  I guess it’s well-known now but I wasted a ton of time trying to feed NMEA into the console terminal after I upgraded to a Pi3.  Worked (with kplex) on the B+.
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