NMEA 0183 sentence for barometric pressure

[conachair]

Originally Posted by richarddaneel

Sorry for the confusion a typo, yes the sentence I used was IIMDA and NOT MDR as indicated, but the barometer still does not recognise IIMDA sentence, any ideas will be appreciated.

thx, richard

I can't work this out either

OK, sending sentences in from an arduino,

//Serial.println("$IIMDA,30,I,1.02,B,10.1,C,,C,,,,C, 158.69,T,,M,3.89 ,N,2,M*09");
Serial.println("$WIMDA,30,I,1.02,B,10.1,C,,C,,,,C, 158.69,T,,M,3.89 ,N,2,M*17");

The top one $IIMDA..... will show up in a dashboard barometer history but won't be entered into logbook konni. And won't be seen in a dashboard containing a baromter dial or textbox.
The bottom one behaves the same and will be entered into the logbook.

Hmmm....

[transmitterdan]

Originally Posted by conachair

Which bit of Opencpn looks for the barometer data?

With the sentence below I can't get the dashboard to display barometer data

$IIMDA,30,I,1.02,B,10.1,C,,C,,,,C,158.69,T,,M,3.89 ,N,2,M*29

However almost the same sentence will be recorded by logbook konni as barometer & temperature..
$WIMDA,30,I,1.02,B,10.1,C,,C,,,,C,158.69,T,,M,3.89 ,N,2,M*37

A bug got introduced into the dashboard near the end of the 4.2 cycle. Try this:

Add the object "Barometric history" to a dashboard. Then the MDA sentence will drive the history display.

The bug in the text only barometer instrument will get fixed in github "real soon now".

[conachair]

Originally Posted by transmitterdan

A bug got introduced into the dashboard near the end of the 4.2 cycle. Try this:

Add the object "Barometric history" to a dashboard. Then the MDA sentence will drive the history display.

The bug in the text only barometer instrument will get fixed in github "real soon now".

Think I just found that

Thanks.

[transmitterdan]

Originally Posted by conachair

Think I just found that

Thanks.

The instrument will work if you are caught in a tropical cyclone because the pressure will be less than 1000 millibars

[simonmtl]

The sentences work if pressure is under 1 bar, this works for me:

$ARMDA,,,0.9923,B,,,,,,,,,,,,,,,,*6

There must be 20 commas in the string.

Using the same string but over 0.9999 bar doesn't work (bug), however, the BaroHist graph works over 1.

I'm sending sentences with an arduino using println:

//baro pressure
String MDA = "ARMDA,,,0.9923,B,,,,,,,,,,,,,,,,"; //must have 20 commas. Example line, static reading for debug
//float press = (float) pressure/100000;
//String MDA = "ARMDA,,," + String(press,5) + ",B,,,,,,,,,,,,,,,,"; //this is the real line, commented for experimenting with debug line above
CRC = String(checksum(MDA), HEX);
CRC.toUpperCase();
MDA = "$" + MDA + "*" + CRC;
Serial.println(MDA);


I now have wind speed and direction (davis anemometer), barometric pressure, compass, water and air temperature, accelerometer and gyro.

The last two are used for computing pitch and roll but I havent found a string that works for OpenCPN so far. Tried XDR to no avail.


Simon

[richarddaneel]

Hi Guys

OK, so you set the baro pressure with the history. However, my version of OP (V8.0) in the I2C section sets the baro output to NMEA OSXDR strings with no option for MDA strings. How did you manage to get OP to output in MDA, many thanks