RPM resolution?

[Endorphin]

EDIT: It seems I've answered my own question - the idea is to Open the openXsensor.ino file in Arduino IDE and this populates the entire project [...] and then Upload

Thanks Kilrah; I'm sure you know what it means!
I guess I will work it out in the fullness of time...........

[Endorphin]

After some assistance from Kalle over on the other thread, I finally got an arduino nano successfully uploaded with OpenXsensor using the Configurator.
I had many failures. The "fix" was to change over to the old bootloader. A tip I found here: https://stackoverflow.com/questions/197 ... responding.

All worked fine after the change.
I hope to test the RPM tacho tomorrow.

[mstrens]

Great that you continued and found a solution.
Success with your RPM sensor.

[Endorphin]

Great that you continued and found a solution.
Success with your RPM sensor.

Many thanks for the code and all the development work your and others have done towards this project.
I look forward to reporting on my sensor again after operational testing.

Jim.

[Endorphin]

EDIT: It seems I've answered my own question - the idea is to Open the openXsensor.ino file in Arduino IDE and this populates the entire project [...] and then Upload

Sure enough, the clues were in that quote all along, thanks Kilrah!
(Oohh, why did I ever doubt it????).

Once I changed my arduino IDE bootloader over to the old bootloader, everything started to work as advised.

Jim.

[Endorphin]

Which is the correct port to plug the openXsensor into a "D" series receiver?
Can somone tell me please?
I was never able to interpret the notation on the rx.

Edit:

I think I have figured it out. Please ignore.

[kalle123]

It is the 'data-stream port'.

How to handle those 3 ports on the RX side is quite clear documented here



br KH

[Endorphin]

Deleted Post.

Project abandoned.

[jhsa]

Project abandoned? Why?? :O

João

[Endorphin]

Project abandoned? Why?? :O
João

Joao,

Only because it is taking far too much time for me to get it working. I have lots of other stuff to attend to. I will not be flying this plane that I wanted RPM for until June, and besides it is not important.
I might get back to it again later on.
Thanks for asking.

Jim.

[jhsa]

Jim, I did do it with an Hal sensor and installed it on an glow engine that I use only for testing. I have been working on some cool stuff for a glow airplane that I have, but will also have to finish it.. One of the things is a fuel gauge. all using openXsensor. I also built an onboard glow plug driver that reports if a plug goes bad. But I had to put this on hold because of other projects. The RPM part is working fine though. when you come back to it, please remind me of this little conversation Perhaps I can also work on my unfinished stuff. I didn't say anything before because I would have to spend some hours checking what I did and I don't have the time at the moment

João

[kalle123]

Isn't that a thing, we all are suffering from? Too many unfinished projects, projects I want to start with .....

cu KH

[jhsa]

You are absolutely right I have so many (not only for radio control) and I don't know if / when I will have time for them.. TIME is the big problem

João

[Endorphin]

Jim, I did do it with an Hal sensor and installed it on an glow engine that I use only for testing. ........................
João

Joao,

I was just thinking that if and when I get back to it, I will use a hall sensor with a magnet rotated on the chuck in a drill press.
That avoids always going back to the model installation that I have finally got set up really well. I don't want to run the risk of upsetting anything there until, and if, I get an RPM sensor working.
Good tip, thanks.

Jim.

[kalle123]

Hi João.

In German forum I posted this thread about rpm sensors for bl-motors.
http://www.rc-network.de/forum/showthr ... it-Arduino

Both sensors work with oXs.

Then I modified one of those



with an inverter, so that also works now, but that is nothing for putting actually on a model, can only use it on a test stand. Relies to much on a good reflecting surface.

About your solution with the hal-sensor and a magneto. Could you post the circuit of that senor please and did you use it with oXs?

br KH

[jhsa]

Hi, yes, I use it with oXs of course.. Will definitely check your optical solution, thank you. I have chosen the hall sensor because i want to have an onboard RPM sensor, and I guess optical would not work so well in this application I will need to check the circuit and which sensor I used. But it is very simple. I believe it needs only +5V, GND, and I believe it has an open collector output, so it might need a pullup resistor to the +5V on the output pin, depending on if oXs enables the internal pullup on the input or not.. But using an external resistor should not hurt I guess.. And that is it, it should detect when you pass a magnet quickly in front of it.

João

[kalle123]

Some better pics of that modified IR Sensor.





It is just an inverter, I put on it.



The problem here was, this sensor needs a good reflection patch or area.
Some props worked, some not.

You might remember those eproms with a window. Have lots of these very sticky aluminum patches and I used parts from the stickers, to create a reflector. That worked very well.



But about the hall sensor and magneto. How do you cope with the imbalance on the prop?

br KH

[jhsa]

What imbalance? that doesn't matter,. I did put my magnets on the spinner.. Pictures tomorrow

João

[Endorphin]

What imbalance? that doesn't matter,. I did put my magnets on the spinner.. Pictures tomorrow
João

Karl is thinking (I guess) about the weight of the magnet on one side of the hub or whatever it is mounted on.

How to you get a hall sensor to fit if you have the magnet on the spinner?
(The prop is in the way!).

Edit: After looking at Karl's picture below, I now see how you would do it. The magnet would fit at the back of the spinner, correct?

[kalle123]

I take some effort in balancing.

First the spinner without the blades and when I think, the spinner is OK, blades on and balancing the unit.

No idea, how to fit magnetos ...



br KH

[Endorphin]

.................................
No idea, how to fit magnetos ...
.................
br KH

Karl,
If you take a look at the back of the spinner (and maybe show us a picture of it?), I would expect there to be a way to mount the magnet there.
For my CDI, I only use 3 x 2 mm magnets. In an alloy IC engine hub, I stack two of them, one on top of the other.
However, I have reason to expect that one would do.
A small counterbalance weight could be fitted to the opposite side.

Jim.

[kalle123]

Jim, I only fly electric.

And for that, I tested this solution with oXs under FrSky and Multiplex successfully.





The rpm probe goes to one of the brushless motor cables.

Alternatively (when one does not want to solder) I ordered one of those. ~ 3$.

Works fine.



The IR Sensor I used for my test stand. But for working with oXs, I had to invert the OUT signal.

But the IR sensor is, in my opinion, not useful for outside application. The reflecting for the IR sensor is critical.

So my question here, what hal sensor, how to mount it, what circuit for use with oXs?

But João will post some pics here

br KH

[jhsa]

Guys, I am so sorry, been busy with other projects, one of them is building an Flite Test Guinea pig with my little son. Will try posting pictures a bit later.

João

[jhsa]

Here are a couple pictures from my test rig. Sensor is on an L shaped piece of aluminium that is screwed to the engine and engine mount.
The sensor is held in place on the L shaped piece by some shrink tube. Magnets are held in place on the spinner with some glue. I actually drilled a hole of the same diameter of the magnet, and glued it in place. But one is missing, so I guess I didn't glue it very well. But as I said, this is a test rig only.

João

[kalle123]

João, so here



-1- is the hall sensor, -2- the aluminum holder and -3- a disk (plastic?) with two holes with magnets.

Makes sense.

Sensor circuit just simple like that here? https://maker.pro/arduino/tutorial/how- ... th-arduino

How did you test? Just with an oscilloscope, or oXs?

br - KH

PS. Now you can sue me for using (unauthorized ) your picture

[jhsa]

Ha ha, everybody sues everybody for no reason this days
The plastic disk is the back of a broken spinner
I tested it with ErskyTX, and oXs. This is part of a project i have for one of my models. it includes onboard glowplug driver that also detects when the glowplug went open circuit, Cylinder head temperature sensor, and tank level sensor.
I am having issues with the temp sensor. You see, the dumb here glued it with epoxy to the engine's cylinder head. when it gets hot, the epoxy becomes softy I didn't know it. and the fuel tank level sensor is a work in progress. There is someone that apparently did a good implementation. need to find time to check it out.

I believe the hall sensor i used is a non latching switch. it goes high when one of the poles passes in front of the magnet, and then goes low. I will see which one i used and will post here. will also try to find the circuit i used but I think it is just like the one on the link you posted above.

João

[kalle123]

Was faster.

Ordered those here and shall run some tests.

https://www.ebay.de/itm/291793877222

Weather is bad and news tells me, we have climate, refugee and a FrSky crisis, I need some distraction

br - KH

[jhsa]

I think those were the ones I used
there was another project I did a while ago with hall sensors, but another type. I changed the sticks of one of my 9x radios to hall sensor instead of pots

João

[Endorphin]

I use A3144 hall sensors for the CDI installations.
They were ridiculously cheap from ebay / China. 10 pieces for AU$1:40

https://www.ebay.com.au/itm/10PCS-New-O ... SwNJ5Ze~ni

[jhsa]

yes they are.. and they are good.. that is why we use them

João