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NMEA / USB wiring - help welcome ! SOLVED at last !
#1
Hi,
How should I connect the NMEA output of my ST50 tridata repeater to the USB 422/485 adapter ? (see attachments)

       


On the ST50 instrument side are  2 wires 1 "signal" (red) and one "Ground" (blue) ;
On the adapter 5 screw connectors : R-, R+, T-, T+ and GND ;

I checked a signal is present on the ST50 equipment side (analogue multimeter, range 10VDC, the needle moves) ;
I tried, but without success these connections :
  • blue to GND, red to R+
  • blue to R-  red to R+
  • blue to T-, red to T+
  • blue to GND, red to T+
I'm stuck, has somebody already connected one of these NMEA/USB adapters ???
Config : RPi 3, OP 1.0.0 alpha
Cordialement
Didier B





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#2
Hi, 
I'm not expert for this but as can see:

- on transmiter side is ST50 which have TTL(UART) output
- on receiver  side is USB port

That mean you need  UART to USB converter between this two parts.

You have USB to 485 converter, which is different protocol. 

Solution is use UART/USB adapter which is very cheap and just connect red from ST50 to RX, and blue to GND.
Then set baud rate and other and that is must work.

Maybe(just maybe, and I'm not responsible) you can tray connect red(ST50) to T+, blue(ST30) to T- (like you describe in 3nd option of wiring) and T- also to GND of ST30. 
Or 2nd option with R- also to GND of ST30.

Marko
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#3
The ST50 is probably so old that it uses NMEA 0183 version 1. This is not RS422 but RS232.
You should try with a USB-RS232 converter (preferebly isolated). Remember to set the baudrate to 4800 baud.

(02-07-2018, 04:16 AM)marko_st Wrote: - on transmiter side is ST50 which have TTL(UART) output
That mean you need  UART to USB converter between this two parts.

I am quite sure that this would destroy the UART to USB converter because it only handles 0 to 3.3 or 5 V, and this output is probably ±12 V.
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#4
(02-07-2018, 04:18 AM)shipahoy Wrote: The ST50 is probably so old that it uses NMEA 0183 version 1. This is not RS422 but RS232.
You should try with a USB-RS232 converter (preferebly isolated). Remember to set the baudrate to 4800 baud.

(02-07-2018, 04:16 AM)marko_st Wrote: - on transmiter side is ST50 which have TTL(UART) output
That mean you need  UART to USB converter between this two parts.

I am quite sure that this would destroy the UART to USB converter because it only handles 0 to 3.3 or 5 V, and this output is probably ±12 V.
Maybe, but it will only be 12v not +/-12v.

This converter is very cheap so...
Maybe try to measure ST30 output with oscilloscope to check voltage. If it is 12v, you can use simple voltage divider with two resistor.

Poslano sa mog Redmi Note 4 koristeći Tapatalk
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#5
Here is a lot of useful information: http://www.actisense.com/wp-content/uplo...-4-1-1.pdf
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#6
(02-07-2018, 07:57 AM)shipahoy Wrote: Here is a lot of useful information: http://www.actisense.com/wp-content/uplo...-4-1-1.pdf

Thanks a lot, very precious for an NMEA newbie !

(02-07-2018, 04:28 AM)marko_st Wrote:
(02-07-2018, 04:18 AM)shipahoy Wrote: The ST50 is probably so old that it uses NMEA 0183 version 1. This is not RS422 but RS232.
You should try with a USB-RS232 converter (preferebly isolated). Remember to set the baudrate to 4800 baud.

(02-07-2018, 04:16 AM)marko_st Wrote: - on transmiter side is ST50 which have TTL(UART) output
That mean you need  UART to USB converter between this two parts.

I am quite sure that this would destroy the UART to USB converter because it only handles 0 to 3.3 or 5 V, and this output is probably ±12 V.
Maybe, but it will only be 12v not +/-12v.

This converter is very cheap so...
Maybe try to measure ST30 output with oscilloscope to check voltage. If it is 12v, you can use simple voltage divider with two resistor.

Poslano sa mog Redmi Note 4 koristeći Tapatalk
Thanks for yor suggestion of a divider. I guess 12 to 5V ... Any suggestion for the impedance (from ST50 12 V side)  ?
Config : RPi 3, OP 1.0.0 alpha
Cordialement
Didier B





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#7
I tried again to connect the nmea output of my ST50 repeater via the USB to RS422/485 item from sailoog's shop.
When I connect the NMEA ST50 output "signal" to R+, and "ground" to R-, then the Green LEDs starts blinking steadily at circa 1 Hz (which looks good, isn't it ?)

But when I connect the item to the RPI USB Hub, the blinking almost disappears , and though declared in the OP tabs (USB Manager and NMEA 0183) nothing appears in the inspector windows, but a time-out exception message !

Any assistance most welcome !

I also tried an RS232 to TTL adapter cascaded with an RS 232TTL to USB device, without any success...
Config : RPi 3, OP 1.0.0 alpha
Cordialement
Didier B





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#8
Its an ST50+ right ? ST50 doesnt have NMEA output
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#9
(03-29-2018, 03:14 AM)affinite Wrote: Its an ST50+ right ? ST50 doesnt have NMEA output
No affinite, it's an ST50. NMEA output is implemented in the tridata and/or in the repeater. Have a look to the autohelm doc I included in the begining of this thread...
Config : RPi 3, OP 1.0.0 alpha
Cordialement
Didier B





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#10
(03-29-2018, 04:20 PM)Didier B Wrote:
(03-29-2018, 03:14 AM)affinite Wrote: Its an ST50+ right ? ST50 doesnt have NMEA output
No affinite, it's an ST50. NMEA output is implemented in the tridata and/or in the repeater. Have a look to the autohelm doc I included in the begining of this thread...

Didier B
Yes you are right.
Sorry, I misread the ST50 manuals.
I hope you get it working. I will try my ST50 Repeater NMEA output when I go back to the boat but that's not for several weeks
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