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# Question about using P2 for Hardware development.

Posts: 92
edited 2020-07-24 - 20:29:51
I am working on hardware development that uses interleaved, multilayer wire wrapping & signalling of a coil system.
There doesn't appear to be publicly available methods to formulate the magnetic field produced inside this type of winding.

I am looking for code that will calculate the magnetic field on the P2 prototype.

1. My immediate question is:

I am searching for P2 code (or potentially P1 code) = for the magnetic field variables of an interleaved, multi-layer, multi-frequency, phased coil system.

User "Publison" mentioned Smart Pins - to potentially help with the calculations.

2. The coil system primary is a stack of flat, interleaved pancakes. the secondary is a stack of interleaved helical coils with top conical portions.

3. The phase between all adjacent frequencies is 3/2 * pi (270 degrees).

4. The frequencies will be synchronized using this phase & increase by a factor of 4.
Wire lengths will decrease by the same factor for each successive layer.

fR @ 4^13 = 67,108,864 Hz
fR @ 4^12 = 16,777,216 Hz
fR @ 4^11 = 4,194,304 Hz
fR @ 4^10 = 1,048,576 Hz
fR @ 4^9 = 262,144 Hz
fR @ 4^8 = 65,536 Hz
fR @ 4^7 = 16,384 Hz

5. Wire currently being used is 30 AWG copper for all layers - on both primary and secondary (helical & cone).

Can somebody assist?
«1

• Posts: 138
Im having difficulty picturing what your describing.
• Posts: 9,702
edited 2020-07-25 - 10:34:38
Smartpins will help with precision of measurement and control. As can the streamers. The cordic will help with achieving real-time calculations.

There is a few computational hardware blocks:
One is the colour space converter for video output.
Another is digital filtering for the ADC inputs - both smartpins and streamers.
A third is the DDS/Goertzel combined streamer functions.
• Posts: 1,644
As a starting point they can use the P2 to generate the required frequencies to feed the various primary coils and a hall effect sensor/s to measure the effect of the magnetic fields induced in the secondary coils.

Hall effect sensor
Description
DescriptionA Hall effect sensor is a device that is used to measure the magnitude of a magnetic field. Its output voltage is directly proportional to the magnetic field strength through it. Hall effect sensors are used for proximity sensing, positioning, speed detection, and current sensing applications. Wikipedia
• Posts: 505
edited 2020-07-25 - 22:21:52
It sounds like you're prototyping a novel device using the P2 and at the same time trying to derive the underlying math needed to measure results and develop things further. That's a pretty big chunk to chew all at once, especially if you are only casually fluent in All Things Propeller (that would be me too, btw).

You might consider using an arbitrary function generator instead of the P2, at least initially, with a separate push-pull driver stage to provide the drive signals to the coils under test. Even a cheapie (the Rigol DG1022Z comes to mind) would handle this task except for that one 60mhz test point which is out of its range. If you combine this setup with a cheap scope and a quiet afternoon, you could move the ball forward fairly quickly and with less chance of error.

Once you get the math basics ironed-out, then you could bring the P2 into the picture and eliminate the bulky test equipment.
• Posts: 92
JRoark wrote: »
It sounds like you're prototyping a novel device using the P2 and at the same time trying to derive the underlying math needed to measure results and develop things further. That's a pretty big chunk to chew all at once, especially if you are only casually fluent in All Things Propeller (that would be me too, btw).

You might consider using an arbitrary function generator instead of the P2, at least initially, with a separate push-pull driver stage to provide the drive signals to the coils under test. Even a cheapie (the Rigol DG1022Z comes to mind) would handle this task except for that one 60mhz test point which is out of its range. If you combine this setup with a cheap scope and a quiet afternoon, you could move the ball forward fairly quickly and with less chance of error.

Once you get the math basics ironed-out, then you could bring the P2 into the picture and eliminate the bulky test equipment.

The P2 hardware offers the most flexibility to vary the frequencies, phase, and duty cycle - without having to add any other electronics.
Much of this code was already written for the P1 (and I was able to modify it successfully for initial testing).
But P2 performance allows a wider range of frequencies, and potentially allows for adjusting frequencies, phase, and duty cycles within the same program.

As for the magnetic field calculations - the patent for Interleaved Coils was only re-published to the public in 1995.
I am not convinced that updated EM formulas have been written or published for Interleaved coils.
JRoark mentions measuring the EM field with a Hall sensor. This appears to be my initial plan of action.

• Posts: 92
As a starting point they can use the P2 to generate the required frequencies to feed the various primary coils and a hall effect sensor/s to measure the effect of the magnetic fields induced in the secondary coils.

Hall effect sensor
Description
DescriptionA Hall effect sensor is a device that is used to measure the magnitude of a magnetic field. Its output voltage is directly proportional to the magnetic field strength through it. Hall effect sensors are used for proximity sensing, positioning, speed detection, and current sensing applications. Wikipedia

I am not yet clear on how to acquire or construct Hall Effect sensors - or where I would position them within the coil system.
The secondary winding is a helical coil - with a cone-shaped exit point.
It is shaped like a hollow pencil.

1. What would be a placement point for the sensor - for maximizing the magnetic field measurement?
2. Also, how can I acquire or build a cheap & easy Hall Effect Sensor?
3. If there is Hall sensor measurement code for the P1 or P2 - I would also prefer to add this code to my program. Does any exist?
• Posts: 505
Much of this code was already written for the P1 (and I was able to modify it successfully for initial testing).
Post your design and your code and lets see what we can do.

• Posts: 92
JRoark wrote: »
Much of this code was already written for the P1 (and I was able to modify it successfully for initial testing).
Post your design and your code and lets see what we can do.

Ok, I am posting them. I'm ready for questions & constructive criticism - but I want to give a short background first.

Just so people know, Ken Gracey has decided to send me a P2 board based on the amount of work I have put in to this project. It's a civilian version of something successfully performed and published by Boeing - so it has been accomplished already. Google "Plasma Force-field"

Since the details were not given to the public - I took it upon myself to fill in the puzzle pieces and find peaceful purposes for it. I also re-registered with the Selective Service so others wouldn't misconstrue my intentions. I'm trying to lower the power & voltage requirements, to keep the plasma cooler - and keep the device powered indefinitely (sustained) with less than 200 watts.

My P1 code was a rewrite of someone else's open-source code, and requires both the fast_pwm.spin & Synth.spin code to work. My prior experiments with AM electrolysis of water & the Spin-Hall effect are shown on Youtube channel "joabel19711".

The design is reasonably complete at 27 pages. It includes the signalling Trigonometry, wire & coil dimensions, circuit layout, CAD drawings, materials list, water chemistry, patents, and some source articles from Google Scholar.

The list of peaceful purposes is obviously speculation - until the machine is successfully tested. Please don't attack me for this speculative list.
• Posts: 9,702
edited 2020-07-29 - 05:34:14
evanh wrote: »
...
Another is digital filtering for the ADC inputs - both smartpins and streamers.
The ADC digital filters can also be used with external sigma-delta ADC chips. The requirement is they have to be able to output the raw Pulse Density Modulation (bitstream) data.

• Posts: 92
edited 2020-07-29 - 22:14:28
evanh wrote: »
evanh wrote: »
...
Another is digital filtering for the ADC inputs - both smartpins and streamers.
The ADC digital filters can also be used with external sigma-delta ADC chips. The requirement is they have to be able to output the raw Pulse Density Modulation (bitstream) data.

I am looking for a fully integrated solution on the P2 board. I prefer a solution that mitigates as many external components as possible. Even at the sake of losing some performance.

evanh - Can you visualize an integrated solution - involving ONLY the P2, coils, transistors, diodes, and DC power supplies (and spinning spheres)?

The spinning spheres require 2 variable, non-capacitive AC motors that are also controlled through the P2 using Duty Cycle PWM (+/- 30 Hz or +/- 1800 rpm). If the entire solution can be integrated into one P2 program, then we have a limit to what is possible. A starting point.

I'm not saying this requirement for coding is logistically workable, but it offers a controlled starting point.
The design is not being shared by Boeing - so, unfortunately, it starts with a little guess work - and potentially a few mistakes to get there. Is the project worth it to you by keeping it this simple?
• Posts: 92
I apologize for sounding demanding to evanh. I have no experience with project oversight - and have been designing alone for some time - so I am adjusting my personality and tone as we move forward. My overall driving motivations are simplicity and accessibility.

1. There will need to be ALOT of testing, design optimizations and different added features (i.e. magnetic field measurements & control, air quality measurements & control, TLIM control & stability, standing wave control, guidance & navigation, etc.) to create a flexible device that is reasonably easy to operate & troubleshoot, accident-free, and relatively life-enriching (versus harmful) in the presence of plants, animals and humans.

2. If malfunctions occur during testing - minimized external circuitry, will allow us to concentrate on a core P2 program to troubleshoot & test with - and not setup long-term expectations of needing experts in electronics troubleshooting - to sustain it's operation.

3. Ken said the P2 will potentially be in production for 20 years. So, it's not necessarily about creating more jobs, it's about creating access for the most end-users. IF testing succeeds and functional devices get built and operated - a simpler core design leads to less support and more independence for everyone. Average people will be steered towards supporting their own devices with code updates - instead of grabbing a soldering iron. This may sound somewhat familiar.

4. In the context of the P2 program - I would prefer to setup expectations of children being able to operate & maintain Plasma Barriers someday - and yet offer experimentation options for the more advanced researchers. By using this philosophy, plasma barriers can potentially improve ALL branches of science - by giving appealing offerings to researchers outside the realm of computer science or radio engineering.

Scientists have their own branches of research that they may wish to concentrate on. This might include a horticulturist studying plant growth, or a doctor studying longevity. As pathfinders - we should focus in on their own curiosities, and give them the ease & flexibility to get onboard - even though they might not care about HOW plasma barriers work. Again, this sounds a bit like an Operating System commercial.

5. I am convinced the best starting point is the KISS methodology - since there is the potential for a lifetime of possibilities afterwards. If kids can use smartphones, then why not make plasma barriers just as accessible?
• Posts: 92
edited 2020-07-30 - 14:32:42
The current situation in Minnesota:

<Removed>

Quit editing my posts.

I am in International Falls, MN.

I am still waiting for my P2 board.

ModEdit: Content removed which is against published forum guidelines. Please keep close to the topic of Parallax hardware/software on these forums.
https://forums.parallax.com/discussion/134682/forum-rules-and-guidelines#latest
• Posts: 9,702
edited 2020-07-31 - 08:55:52
There is good reason to entertain external ADCs. Each can be operated from a dedicated isolated power supply. This is very good for removing common mode (think ground loops) interference. The data for the ADCs can be piped though a couple of high speed digital optocouplers each - One for PDM data the other for PDM clock. Makes for robust and reliable designs.

The good news is that switching between an internal prop2 ADC and an external PDM ADC is quite straight forward. So you can happily start with all analogues on the single common ground and using just prop2 analogue inputs. And if any become a hassle due to sensitivity or high currents or static discharges it's easy to switch the software over to an external PDM based ADC on an individual basis. Only thing to be aware of is the PDM data rate will be slower for external parts. Typically in the 10-20 Mbit/s range. The prop2 internal ADCs operate at sysclock so they do have a speed advantage.

Using SPI, to read in already filtered PCM samples, is also an option but this then has more optocouplers, SPI timing constraints, and a bunch of software configuration involved. Whereas PDM based ADCs have no need for any device config programming, it all stays internal to the prop2 hardware.

• Posts: 92
I will need to receive my P2 before moving forward with any programming & testing. But, from my experience with the P1 - I'm under the perception that I can mitigate most external electronics.

Pushing a philosophy of making things harder than they need to be - doesn't get me far.
You can see from my last post - that I am following the path of simplicity & accessibility.
• Posts: 9,702
edited 2020-07-31 - 14:09:44
What I've described is the simple way. You can switch between internal and external ADC on a case by case basis without replacing the software routines. It's just a bit or two to flip in the smartpin config.

There is a couple of reasons to go a more complex path though: One is 24-bit low speed sampling for instrumentation. For this, SPI is the norm for things like weigh scales and temperature measuring. It would be interesting to see how far the internal prop2 ADCs can be pushed in this area.

The other is very fast 8-bit or 10-bit sampling. For this, you'd be looking at a parallel bus for things like video capture, modems and storage scopes. The scope mode of the streamers is already doing well here though, so even this is an unlikely candidate to go external.
• Posts: 92
edited 2020-07-31 - 16:24:22
Evanh's response is based on the assumption that interference will affect the output of the board.
He doesn't have a way of knowing that. I have contacted Ken in response to this concern, but, until confirmation of such problems by the manufacturer - I am convinced evanh's way is not "THE simple way", as he states.
• Posts: 92
We've heard much from "evanh".

Does anybody else have some input regarding coding - versus yet-to-be tested external interference issues? We need code before we could even test evanh's concerns.

Can we put the horse before the cart - and see what type of program we can come up with first?

• Posts: 1,409
edited 2020-07-31 - 18:35:16
Why do you have to reply to people in the third person "by name" with scare quotes? You talk like you're addressing the fourth wall in a show. Don't you think people would be more eager to help you if you addressed people with the ordinary you instead of being so condescending?

• Posts: 92
The P2 is easier to operate then is being explained.

The answer is simpler than you both let on. If a simpler solution is available without the Smart Pins - then that was not my recommendation. It was Publison's.
• Posts: 505
edited 2020-07-31 - 19:32:06
The P2 is easier to operate then is being explained.

The answer is simpler than you both let on. If a simpler solution is available without the Smart Pins - then that was not my recommendation. It was Publison's.

Good to know. I'll put you down as not needing any further help then.

As you note, this stuff is pretty trivial. In fact, one of my 17 year old Minions got this far (pics) with a FlexBASIC driver on the P2. Sine and square, because good engineers plan ahead for improvements and flexibility... and she's going to make one heck of an engineer someday.

Edited to add: There are actually two more channels being output by the P2 (total of 4), but due to an... ahem... "conflict" between the lab cat and those two probes (you can't make this up), the two replacement probes likely won't get here until tomorrow or Monday.

• Posts: 92
Good, maybe they're young enough to be open minded - and want to work on a Plasma Barrier.
Send them the design.
• Posts: 505
I’m going to hold off on that for a bit. In the thread below you indicated that you had an NDA with Trump Tower re the plasma barrier. My day job is law, so I’d like to see the release before I turn this over to the kids.

Certainly there is lots of interest, but I owe a duty to these fledgling engineers to keep the lawyers off their back. All of this is easily cleared-up by a quick review of the release. Hope you understand. PM me for a fax number.
• Posts: 9,702
edited 2020-08-01 - 00:08:29
I'm not proposing any specific answer. Just giving some options ... and recommendations, I guess. Noise is an ever present hindrance. Especially on analogue inputs. Even if something is good enough for the moment, it can always be refined.

• Posts: 92
JRoark wrote: »
I’m going to hold off on that for a bit. In the thread below you indicated that you had an NDA with Trump Tower re the plasma barrier. My day job is law, so I’d like to see the release before I turn this over to the kids.

Certainly there is lots of interest, but I owe a duty to these fledgling engineers to keep the lawyers off their back. All of this is easily cleared-up by a quick review of the release. Hope you understand. PM me for a fax number.

The Non-disclosure was for RELATED research (not a Plasma Barrier) - since I was able to get AM electrolysis of water to work (as a volunteer at NDSU) using a design on Jean-Louis Naudin's website. It was signed in 2012 and I was relieved after being sent an email by Urial Rubinov (CEO of Credit Veritas) in Trump Tower last September.

I never actually understood the legal jargon - and was simply pressured/coerced into signing it. The only knowledge that I was relieved of it - was through the email sent last year. I can send you that as well.

Let me know.
• Posts: 505
Unfortunately, thats not a lawful, formal release which means there isnt a valid release. Thats a showstopper. You might want to discuss this matter with your attorney before going too far. Good luck.
• Posts: 92
edited 2020-08-01 - 02:24:54
Never mind about the fax, I will just post it here. Regardless of your questionable qualifications in law - you can analyze the document and get back to me with your findings. There might be a stated statute of limitations on release - which wouldn't need another formal document. Let me know - since I don't have access to lawyers. Enjoy

You can even contact Uriel Rubinov if you want to do everyone a favor - and request the information you seek. Maybe you will get a response from someone more important. urubinov at creditveritas.com

Regardless, the Non-disclosure was not for a Plasma Barrier - it was for AM electrolysis of water - so your kids are welcome to move forward with their research.

I have just emailed Uriel at Credit Veritas - requesting the document that you seek.
If you want a civilian Plasma Barrier then you might want to help with - what you feel - is required.

I notice that the only people with critical responses have similar cartoon Avatars.

Potentially you are related somehow to evanh & Publison. Perhaps, you are working against the need for a Civilian Plasma Barrier - or only want certain people to do it. By open-sourcing the project - it really doesn't matter.
• Posts: 505
Out of an abundance of caution you may wish to edit your post due to the presence of personally-identifiable data. Under no circumstances would I ever suggest, or permit, a client to publish a document of this nature in a public venue.
• Posts: 92
edited 2020-08-01 - 03:02:19
Removed post.
• Posts: 92
edited 2020-08-01 - 03:02:58
JRoark wrote: »
Out of an abundance of caution you may wish to edit your post due to the presence of personally-identifiable data. Under no circumstances would I ever suggest, or permit, a client to publish a document of this nature in a public venue.

Except under extreme circumstances. This non-disclosure means nothing to me - due to the amount of delays, misinformation, and problems it has caused America. The Clock now sits at 100 seconds to Midnight - and you are attempting to bog down open-source research - with legal jargon.

Are you a protectionist?

I am sorry for ever signing it - and I am publishing it here so it can be used by the open-source community to make up it's own decisions about me - and whether to move forward with Plasma Barrier Technology.
• Posts: 16,392
troll
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