2021-06-10, 03:34 PM
Folks:
My Raspi 4 is extended with a pican-m HAT. Connection to NMEA2000 - send and receice - is working well. I am struggling with connecting to my Standard Horizon GX-2100 vhf to send position and SOG using the rs422 screw connector of the pican-m.
Everything seams to work fine but the GX-2100 does not recognize the data.
I am using the signalk-to-nmea0183 plug-in to and selected to send GLL, GGA and RMC sentences. These sentences originate from OpenCPN where a UDP Connection is used to transfer them to signal-k. The data can be seen in the signal-k serial stream log and can be captured from from my windows-pc when I conncet it to the rs422 screw connector instead of the vhf.
The "strange" behaviour is, that the NMEA sentences are received in chunks of exactly 512 bytes with a 5 seconds delay between them. This implies that the last sentence is never complete unless the 512 byte chunk directly ends after the sentences cr+lf characters.
I would expect that the pc receives the data "as sent" without delay and without cut in chunks and I wonder if this is the reason for my problem. Does the GX-2100 drop the received data when the last sentence of a chunk is incomplete?
Question: How can I convince the Raspi/pican HAT to sent every sentence immediatly after it was emitted by signal-k?
Best Regards
Michael
My Raspi 4 is extended with a pican-m HAT. Connection to NMEA2000 - send and receice - is working well. I am struggling with connecting to my Standard Horizon GX-2100 vhf to send position and SOG using the rs422 screw connector of the pican-m.
Everything seams to work fine but the GX-2100 does not recognize the data.
I am using the signalk-to-nmea0183 plug-in to and selected to send GLL, GGA and RMC sentences. These sentences originate from OpenCPN where a UDP Connection is used to transfer them to signal-k. The data can be seen in the signal-k serial stream log and can be captured from from my windows-pc when I conncet it to the rs422 screw connector instead of the vhf.
The "strange" behaviour is, that the NMEA sentences are received in chunks of exactly 512 bytes with a 5 seconds delay between them. This implies that the last sentence is never complete unless the 512 byte chunk directly ends after the sentences cr+lf characters.
I would expect that the pc receives the data "as sent" without delay and without cut in chunks and I wonder if this is the reason for my problem. Does the GX-2100 drop the received data when the last sentence of a chunk is incomplete?
Question: How can I convince the Raspi/pican HAT to sent every sentence immediatly after it was emitted by signal-k?
Best Regards
Michael
SY Neptune's Car
Sigma 33 OOD
DG3612