Plugin: DashBoard

[Hakan]

Hubert...

I've a list orginated by:
= NMEA Revealed =
Eric S. Raymond <esr@thyrsus.com>
v2.8, Feb 2011

Extract:
== Vendor extensions ==
This list is very incomplete.
=== PASHR - RT300 proprietary roll and pitch sentence ===

------------------------------------------------------------------------------
1 2 3 4 5 6 7 8 9 10 11 12
| | | | | | | | | | | |
$PASHR,hhmmss.sss,hhh.hh,T,rrr.rr,ppp.pp,xxx.xx,a.aaa,b.bbb,c.ccc,d,e*hh<CR><LF>
------------------------------------------------------------------------------
Field number:
1. hhmmss.sss - UTC time
2. hhh.hh - Heading in degrees
3. T - flag to indicate that the Heading is True Heading (i.e. to True North)
4. rrr.rr - Roll Angle in degrees
5. ppp.pp - Pitch Angle in degrees
6. xxx.xx - Heave
7. a.aaa - Roll Angle Accuracy Estimate (Stdev) in degrees
8. b.bbb - Pitch Angle Accuracy Estimate (Stdev) in degrees
9. c.ccc - Heading Angle Accuracy Estimate (Stdev) in degrees
10. d - Aiding Status
11. e - IMU Status
12. hh - Checksum
[PASHR] describes this sentence as NMEA, though other sources say it is Ashtech
proprietary and describe a different format.
Example: $PASHR,085335.000,224.19,T,-01.26,+00.83,+00.00,0.101,0.113,0.267,1,0*06

Håkan

[rgleason]

Big Tom:

I created a simple text style instrument "Polar-/Targetspeed", giving me the theoretical speed / percentage based on the polar at the momentary TWA (see at the bottom)
This is not yet the "target VMG" (=optimum speed towards a WP, with possibly a different TWA)...

Jman about Target Boatspeed:
http://www.cruisersforum.com/forums/...ml#post1926219

...12 knots of breeze, my optimal upwind angle is 33.5 degrees. If you just go to that number without getting up to speed first, you would likely start going backwards. This is where the Polars do start coming into play, and why racing yachts don't care about a polar angle. It is called target boat speed. So on a racing boat you pick the boat speed number on the polar curve, for the wind speed at that instant, that gives you the best VMG (towards or away from the wind not the destination) number (well the instruments do, both upwind and down). Then you rely on the crew to trim the sails perfectly. Then the helmsman heads up or down as necessary to get the boat to the target speed, since the math works both ways, if you are at target speed, you should be at the best angle. As wind velocity changes the target speed changes, and is much more intuitive to follow.

[bcn]

Originally Posted by Hakan

Hubert...

I've a list orginated by:
= NMEA Revealed =
Eric S. Raymond <esr@thyrsus.com>
v2.8, Feb 2011

Extract:
== Vendor extensions ==
This list is very incomplete.
=== PASHR - RT300 proprietary roll and pitch sentence ===

------------------------------------------------------------------------------
1 2 3 4 5 6 7 8 9 10 11 12
| | | | | | | | | | | |
$PASHR,hhmmss.sss,hhh.hh,T,rrr.rr,ppp.pp,xxx.xx,a.aaa,b.bbb,c.ccc,d,e*hh<CR><LF>
------------------------------------------------------------------------------

Håkan

Håkan...

this a funny one.
THIS vendor and their proprietary sentence I do know very well:
http://www.oxts.com/contact-us/sales...tatives/spain/

Hubert

Ps.: It's RT3000 not RT300 and the complete manual for the NMEA0183 sentences used is here http://oxts.com/Downloads/Support/NMEA/nmeaman.pdf

[Hakan]

Hubert...
Sorry, thought you where asking, but many thanks for the nice links
Håkan

[bcn]

Håkan...

why sorry?
I have been asking for the sentence Matthew is using and as NMEA0183 is not free, who knows which sentences are hidden somewhere. And I do not plan to become a member of NMEA in order to license the standards neither.

Hubert

[rgleason]

've a list orginated by:
= NMEA Revealed = Eric S. Raymond <esr@thyrsus.com> v2.8, Feb 2011

This is version 2.19
NMEA Revealed

[Neptune's Gear]

This new plugin looks really promising. Target boatspeed from polars and tack and lay info is what I would really like. I'd be keen to try a copy, and perhaps help with debugging (but I'm no programmer, just a user!) when it is practical, but it would have to be in English, and run on windows :-)
Thanks for your efforts guys!!

[Hakan]

Originally Posted by bcn

Håkan...

why sorry?
I have been asking for the sentence Matthew is using and as NMEA0183 is not free, who knows which sentences are hidden somewhere. And I do not plan to become a member of NMEA in order to license the standards neither.

Hubert

Ahaaa.. I misunderstood, sorry!(You know, not native English!)
Well, your q to Matthew is then really relevant. In my home made compass unit (Arduino) I've the opportunity to transmit pitch and roll but then I also need to know how the SHR should be set up to fit the new instrument.
Håkan

[bcn]

Håkan,

the good thing about the OxTS/RT3000 sentence is that it carries the time stamp.
And typical for an inertial measurement unit the error estimate of the internal Kalman filters which gives you a pretty good idea about the quality of your data in a given moment.
What we are getting on our boat are precisions of 0.1° for heading and 0.07° for pitch&roll with the unit we have at hand. 100hz output.
Overkill for what we need normally but a nice toy...

Hubert

Ps.: with the Arduino you might consider SignalK for your data streams

[Hakan]

Hubert..
SignalK looks nice and has a lot of exciting features for future considerations.

In my present set-up I transfer NMEA to my Simrad IS15 system and that way the HDM is further transferred into OCPN. But if I'd like to also Tx SHR to OCPN I may have to redo some stuff. The IS15 bus will not read SHR.
Thanks
Håkan

[tom_BigSpeedy]

Hi guys,

FYI : NKE uses the XDR sentence to send out Roll and Pitch.
That's already implemented in dashboard.
Just check dashboard_pi.cpp and query for XDR.

I went sailing this weekend, and had a close look at the current status of my implementation ... not much wind though, but enough to pull up the sails and verify the current direction/speed display and the laylines.
Found a bug related to data filtering around northerly directions (when values jump from 3xx°<-->0xx° forth and back). But that's already fixed by now.
The promising thing is, that the display of (sea) current direction and speed is almost identical to what my NKE instruments tell me. Short term deviation was less than 5°, and regarding the fact that I'm using a different damping constant and I have to read the instrument in the cockpit, then stick my head inside the boat to verify it on the O display this is OK, I'd say ...

I still noticed bugs in the polar-speed and VMG/CMG, target-VMG displays...

In short : work is still in progress ...

Thomas

[Hakan]

XDR seems rather undefined as well?? How is that commonly used for pitch&roll?

XDR Cross Track Error – Dead Reckoning
1 2 3 4 n
| | | | |
$--XDR,a,x.x,a,c--c, ..... *hh
1) Transducer type
2) Measurement data
3) Units of measurement
4) Name of transducer
x) More of the same
n) Checksum

Håkan

[tom_BigSpeedy]

Hi Håkan,

it seems that XDR is seen as the recommended multipurpose sentence ...
You missed the important sentence :

** There may be any number of quadruplets like this, each describing a sensor. The last field will be a checksum as usual.

So you can have multiple data in one sentence.

Here are some examples from my (NKE-style) NMEA stream :
$IIXDR,C,15.7,C,AirTemp*25
$IIXDR,A,-0.5,D,PTCH,A,-1.0,D,ROLL*58
$IIXDR,A,-0.6,D,PTCH,A,-0.9,D,ROLL*53
$IIXDR,A,-0.7,D,PTCH,A,1.4,D,ROLL*73

ROLL = Heel , neg. values are roll/heel to left AFAIR
PTCH = Pitch = Nose up/down
I had somewhere the description of the 'transducer type', I remember A=angular, C = temperature, etc.
And 'unit of measurement' is like D=Degree, C=°C, P=%, etc.

Let's see if I can find it somewhere ...

All 3 are already implemented in O.

Thomas

[Hakan]

Thomas..
Thanks, looks like a very useful message!
Håkan

[tom_BigSpeedy]

Originally Posted by rgleason

Big Tom:

Jman about Target Boatspeed:
http://www.cruisersforum.com/forums/...ml#post1926219

Rick,
already in progress, I planned to do it anyway. Also a pointer in the bearing compass showing you the (optimum) target VMG angle

But target VMG is only favoured on close haul or downwind. When reaching (cross wind) normally polar speed gives better results ...

Thomas