Analog motor sensors

[Sailoog]

Hello Members.
I have been using OP for a few months and playing around with all its functions. Very impressed with the stability and ease of use.
I was going through some of the threats and noticed the same request that I was wondering about; Interfacing to the engine.

Instead of trying to adapt to existing sensors, I was thinking to add additional sensors to my engine. This was I can keep my old (40 year old) analog gauges and add a complete independent monitoring system.
I happen to have a perfect solution already ready for this. For one of my other projects (eosweather.ca) I developed a PCB to get sensor data from weather sensors. This board can be used for Engine sensors (temp, pressure, rpm's etc) as well. All sensors would be 0-5VDc or 4-20mA. After collecting the analog data, the PIC microcontroller can send an NMEA data string to the OP!
The nice thing about this PCB is that it fits directly onto the GPIO connector of a RPI!

I will start getting some sensors and over the next few months will make this work.
Does anyone have the NMEA0183 data string for engine data. I found $--RPM but that only contains RPM data...
Also, it would be nice to have some gauges to display the data

Thanks
Henk

Hi Henk,

First of all sorry for not answering the email you sent me few days ago. Too much work and few time, as usual...

That sounds really great. I would be glad to help. OpenPlotter can also deal with all kind of sensors but an intermediate arduino/PCB could simplify the wiring and make all safest.

The bad news is that NMEA 0183 doesn't have sentences for most engine data. You could use XDR sentences but there is not a standard for this sentences and every device uses its own ID and settings. Since this is a common issue for all projects, OpenPlotter included, we are working hard to fully implement the new open protocol Signal K to OpenPlotter. Signal K specification allows to deal with all kind of data. This is how OpenPlotter will work:

Inputs

• All NMEA 0183 inputs are converted and stored in Signal K model  (serial, network)
  
• All NMEA 2000 inputs are converted and stored in Signal K model (serial)
  
• All the digital and analog sensors connected to OpenPlotter generate Signal K data directly (1W sensors, I2C sensors, GPIO sensors, SPI sensors) and stored in the Signal K model.
  
• All the notifications get by MQTT, SMS or OpenCPN are stored in the Signal K model.
  
• OpenPlotter calculate new data (true wind, rate of turn...) and generate Signal K data directly.
  

outputs

• Built in apps to show instruments from signal K model in your remote devices.
  
• Send Signal K data to any specific external app.
  
• OpenPlotter actions system uses Signal K values as triggers to run multiple actions.
  
• Built in app for build NMEA 0183 from Signal K data (not a converter, a builder to send custom NMEA 0183 data, ex. you could send the XDR data that OpenCPN or any devices likes)
  
• Signal K to NMEA 200 converter to send data to your NMEA 2000 network.
  

So we recommend you to send Signal K data to communicate with OpenPlotter. If this is not possible, OpenPlotter could convert NMEA 0183/2000 data to Signal K but you will not be able to find the right sentences to send most sensors data. I could guide you to choose the right Signal K values to send and the right format.

What do you think?

More info:

http://signalk.org/
A similar project:
https://bitbucket.org/R_P_Ryan/enginemonitor/wiki/Home
https://bitbucket.org/R_P_Ryan/enginemon...ersion_2_0
A tutorial to send Signal K from arduino:
http://blog.emilecantin.com/web/sysadmin...art-1.html
http://blog.emilecantin.com/web/sysadmin...art-2.html

I will reply your email as I have some time, sorry again