Getting -1 from reading NMEA 0183 sensor

Projects General Guidance
1

Hi guys,
I connected my NMEA 0183 depth sensor from CruzPro to my Arduino using a ST232CN converter.
This is my setup: Imgur: The magic of the Internet
The sensor wants 12V, so i powered it from external power supply.
I studied the schematic of ST232CN, and i think i made the right connections. Here you can find the datasheet: MEGA
And here is my Arduino code:

 #include <SoftwareSerial.h>  
 #include <nmea.h>  
   
 SoftwareSerial nmeaSerial(10,11,true); // RX pin, TX pin (not used), and true means we invert the signal  
 NMEA nmeaDecoder(ALL);   
   
 void setup()  
 {  
  Serial.begin(4800);  
  nmeaSerial.begin(4800);  
 }  
   
 void loop()  
 {  
  Serial.println(nmeaSerial.read());
   if (nmeaSerial.available() > 0 ) {  
    
     if (nmeaDecoder.decode(nmeaSerial.read())) {  
     Serial.println(nmeaDecoder.sentence());  
    }  
   }
 }

The problem i found is that my Arduino only prints "-1", so that means nmeaSerial is not available, but I can't understand why... NMEA OUT wire is connected to a RS232 input, while Arduino is connected to the respective TLL Output.
Thank you for your time,
Simone

2

Make sure that the transmit pin of one device is connected to the receive pin on the other, and vice versa.

3

JohnLincoln:
Make sure that the transmit pin of one device is connected to the receive pin on the other, and vice versa.

I follower this schematic and connected signal from NMEA sensor to pin 13 of ST232CN and pin 10 of Arduino (setted as Receiver in the software serial from Arduino sketch) to pin 12.
Imgur: The magic of the Internet Here you can see the schematic from ST232CN

4

The websites that you are posting your additional information on are blocked by my company security policy. I will look at them later from home.

5

JohnLincoln:
The websites that you are posting your additional information on are blocked by my company security policy. I will look at them later from home.

thank you very much. By the way, i'm uploading the image here too

6

garu94:
thank you very much. By the way, i'm uploading the image here too

I'm home now, and I find that I am asked for the decryption key!

.... so it is good that you posted it here

7

I think you need to connect the Arduino ground to the depth sounder ground.