Expedition Navigation Software 
1 - sheldon.haynie
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- From: San Francisco Bay
- Registered: 1/13/2016
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Paddlewheel(s) B&G vs Exp questions
1.Is there any means to do a multipoint calibration of boat speed in Exp?
I seem to be able to get a single point matched to SOG but it under reads below 3 kts, and over reads above 7.
(My B&G H5000 allows for single point magnitude and then a heel correction table.
I had set my BSP multiplier percentage to match SOG under power at 6 kts
not yet activated the heel correction as this seemed to be a basic error in underlying calibration. It’s not clear that the venerable Westerbeke will push much faster than 6, though will try next time out. )
“
What is the algorithm H5000 uses?
Is it # of pulses in fixed time, or time for fixed number of pulses?
Is the raw pulse count available on websocket ?
In terms of damping, or averaging, is it feasible to have an option based on number of pulses vs number of seconds? That would change the period inversely proportionally to speed.
2. We have two paddlewheels, and even with H5000 set to only use one, the TWA calc in H5000 seems to be trying to read the one that is not working on that tack.
Can I set Exp to force it to read the single sensor in all conditions?
3. Is there (future?) a means to switch to SOG if the BSP is significantly different for a sustained period ? E.g. very light air when SOG might be 2kts, and BSP <1.
Semiconductor Development Engineer, Retired Viticulturalist, Occasional sailor
"Lioness" 1962 Hinckley Bermuda 40 Custom Yawl
- birger
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- From: Oslo, Norway
- Registered: 5/05/2016
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Re: Paddlewheel(s) B&G vs Exp questions
I think that’s normal for most paddle wheel logs, I am going to put in the same corrections for all angles of heel, even 0 for all values in my h5000 system as I have the same system...
Not done yet, but have the same issue
- Nick
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Re: Paddlewheel(s) B&G vs Exp questions
Is the heel switch set up backwards?
- sheldon.haynie
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- Registered: 1/13/2016
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Re: Paddlewheel(s) B&G vs Exp questions
Don’t think so, it reads correct paddle leeward and downward side.
H5000 calculation seems to not use single paddle, but forces both, even when when single is selected from Zeus2 sources.
Birger, interesting idea to use heel correction for multiple point. Will have to look at that.
Semiconductor Development Engineer, Retired Viticulturalist, Occasional sailor
"Lioness" 1962 Hinckley Bermuda 40 Custom Yawl
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Thread Starter- sheldon.haynie
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Re: Paddlewheel(s) B&G vs Exp questions
How hard would it be to extract the period of harmonic motion and automagically set averaging window to a multiple for purposes of calculating %polar and %target ?
Semiconductor Development Engineer, Retired Viticulturalist, Occasional sailor
"Lioness" 1962 Hinckley Bermuda 40 Custom Yawl
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Thread Starter- Nick
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Re: Paddlewheel(s) B&G vs Exp questions
Everything is possible, but often things are the benefit vs the over-heads. Exp has multiple threads busy working away in the background and I put a lot of effort into keeping the computer resource impact low.
- sheldon.haynie
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Re: Paddlewheel(s) B&G vs Exp questions
Might be time for a Raspberry Pi/Arduino project....
Assuming I was able to get the data from NMEA 2000 stream and create an externally processed boat speed
to my fancy, is there an elegant means to import that back in?
Semiconductor Development Engineer, Retired Viticulturalist, Occasional sailor
"Lioness" 1962 Hinckley Bermuda 40 Custom Yawl
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Thread Starter- rbhun
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- Registered: 7/05/2019
- Posts: 124
Re: Paddlewheel(s) B&G vs Exp questions
sheldon.haynie wrote:
1.Is there any means to do a multipoint calibration of boat speed in Exp?
I seem to be able to get a single point matched to SOG but it under reads below 3 kts, and over reads above 7.
I have the exact same question. My Raymarine offers a single calibration factor and it looks like I need different numbers for diffeeent speeds. Can this be done? The bsp calibration in the menu seems to be Bsp vs Heel which is different, I guess?
Thanks
- Nick
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Re: Paddlewheel(s) B&G vs Exp questions
Yes, see the Bsp cal interface in Exp. The default is bsp across in intervals of 5kt.
- rbhun
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- Registered: 7/05/2019
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Re: Paddlewheel(s) B&G vs Exp questions
I’m sorry nick, can you point me where? I click on the exp icon top right. Instruments, exp calibration, but there I only see the nap vs heel? I searched the manual too but cannot find it. I’m sorry.
Last edited by rbhun (7/19/2019 12:36 am)