Also send I2C sensor data to Node-Red so ALL instruments show on the dashboard

[PaddyB]

So anyways, I managed to make our analog oil pressure sensors work with an Arduino Uno board I had lying around and send it over I2C to OpenPlotter, until I realized that you can only add sensors that were pre-configured in OpenPlotter, 

You can send the data direct to signalk over serial from the arduino, like this - 

Code:

#include "ArduinoJson.h"
int LED_pin = 2;


void setup() {
 // put your setup code here, to run once:
 Serial.begin(4800);

// Serial.println("Starting Up, Please Wait...");
 // initialize digital pin LED_BUILTIN as an output.
 pinMode(LED_pin, OUTPUT);
}

void loop() {
 // put your main code here, to run repeatedly:

 int randon_num = random(1, 300);
 sendSigK("mytest.test.test", randon_num);
 
 int state = digitalRead(LED_pin);
 digitalWrite(LED_pin, !state);
 delay(2000);

}



void sendSigK(String sigKey, float data) {    //    send SigK


 DynamicJsonBuffer jsonBuffer;
 String deltaText;

 //  build delta message
 JsonObject& delta = jsonBuffer.createObject();

 //updated array
 JsonArray& updatesArr = delta.createNestedArray("updates");
 JsonObject& thisUpdate = updatesArr.createNestedObject();   //Json Object nested inside delta [...
 JsonArray& values = thisUpdate.createNestedArray("values"); // Values array nested in delta[ values....
 JsonObject& thisValue = values.createNestedObject();
 thisValue["path"] = sigKey;
 thisValue["value"] = data;

 thisUpdate["Source"] = "ESP11";
 delta.printTo(Serial);
 Serial.println();
}

Then you need to add this to   /home/pi/.signalk/settings.json - underneath the lines >
 },
  "loggingDirectory": "/home/pi/Logs",
  "mdns": false,
  "pipedProviders": [

Code:

{
      "enabled": true,
     "id": "nmeaFromFile",
     "pipeElements": [
       {
         "type": "providers/serialport",
         "options": {
           "device": "/dev/ttyUSB2",
           "baudrate": 4800,
           "toStdout": ["nmea0183out1", "nmea0183out2"]
         },
         "optionMappings": [
           {
             "fromAppProperty": "argv.nmeadevice",
             "toOption": "device"
           },

           {
             "fromAppProperty": "argv.nmeabaudrate",
             "toOption": "baudrate"
           }
         ]
       },
       {
         "type": "providers/from_json",
         "options": {
           "sentenceEvent": "nmea0183in1"
         },
         "optionMappings": [
           {
             "fromAppProperty": "selfId",
             "toOption": "selfId"
           },
           {
             "fromAppProperty": "selfType",
             "toOption": "selfType"
           }
         ]
       }
     ]
   },

Then it should be added as signalk. Opencpn only see NMEA data so you'll need to convert it to NMEA it you want to see the data in that prog.