Hall-sensor for Jeti

[TeroS]

Hall-magnetic sensor for Jeti, status-update:

Got a UPS package today with "enough" hall-sensors. I had only one to play with last week, apparently it does not like too much voltage. If all goes well sensor and how-to is ready this week. Cost of sensor will be staggering. At least 5$, maybe even 7$.

A question for you: What RPM's do you need it to do??

[Shogun71]

For me the biggest would be for main shaft aka head speed.

That would be amazing to get accurate, plug-in sensor for main head speed readout on the transmitter!!!!

Not sure how that would be accomplished. Maybe tiny magnet on the main gear close to the shaft?

[Esprit Model]

Something like MRPM2 ?

Zb/Jeti USA

[Shogun71]

Originally Posted by Esprit Model

Something like MRPM2 ?

Zb/Jeti USA

I guess like that but I can't find that model number. Just the optical MRPM.

Would the optical unit work with say a main gear or maybe a black dot on the main shaft?

[cbdane]

Here's an old post that shows another possibility. This is before I learned to program my own Jeti telemetry devices (https://www.helifreak.com/showthread.php?t=655425) so it is based on the standard Jeti brushless sensor. Not as cheap and elegant as I'm sure your solution will be but it does the job very well. I still run it on my nitro and turbine helis.

It's possible to put it together with no soldering, just using a standard y-harness (switching a couple of pins in the plugs) or you can solder up a compact version as shown below.

https://www.helifreak.com/showthread.php?t=639545

[Baedarlboo]

Originally Posted by TeroS

Hall-magnetic sensor for Jeti, status-update:

Got a UPS package today with "enough" hall-sensors. I had only one to play with last week, apparently it does not like too much voltage. If all goes well sensor and how-to is ready this week. Cost of sensor will be staggering. At least 5$, maybe even 7$.

A question for you: What RPM's do you need it to do??

Since electric helis seem to have elegant solutions for telemetry (Jlog and soon Brain integration with telemetry), I was in the hunt for a nice (and cheap) solution for my nitro. I was hoping with the Arduino you can feed the hall sensor and NTC thermistor (cheap spektrum temp sensor) for a Jlog'ish type solution. All in one so to speak for nitro. Most 700 nitros run around 1950-2050 max head speed with gear ratios in the 8.0-8.2 : 1 range. I dug around and found bits and pieces but haven't been able to string everything together.

[TeroS]

Originally Posted by Esprit Model

Something like MRPM2 ?



Zb/Jeti USA

What MRPM2? Only reference to "2" after MRPM is in thread?

[dogbreath]

My MRPM's wouldn't work on a 360 heli. Esprit's explanation was that the motor turns too fast. That made me switch to Unisens which had no limitations. I'd like any Hall sensor to work on the smaller motors/higher head speeds (turning fast) as well as the bigger helis turning slower, of course.

Dan

[TeroS]

What's "fast" for you?

[dogbreath]

If you're sensing shaft rotations, I read of some 360-380 speed heli's running near 4000 RPM. If you're using motor RPMs, MRPM (is there a new MRPM2?) had a motor limit around 25K, and at 2800 RPM on my chase that was over 30K on the motor.

Dan

[Esprit Model]

Originally Posted by TeroS

What MRPM2? Only reference to "2" after MRPM is in thread?

There is new MRPM2 sensor with dual input, hall sensors and EXT programming coming up in January.

Zb/Jeti USA

[dogbreath]

Originally Posted by Esprit Model

There is new MRPM2 sensor with dual input, hall sensors and EXT programming coming up in January.

Zb/Jeti USA

Any motor RPM limitations like the original?

Dan

[TeroS]

About the motor-limitations, we have to remember that the MRPM is taking the count from motor and that is headspeed x gear-ratio, comes up to quite big numbers really quick on smaller motors with big kv-values.

This issue is not present when using hall-sensors and counting rpm from magnets on main-gear

I really like that Jeti is coming with hall-sensor finally, I think I'll finish mine anyway, there is a difference in 5$ and 50-60$ sensor for some users. Of course you pay more you get more programming etc

[Necroscope]

So what would you use for sensing rpm for a 1800 Kv motor?
I am looking for my 450L and 470L.

[TeroS]

MRPM-AC, a Jeti sensor. Connects to motor cable.

[Baedarlboo]

[TeroS]

It's been long due but this project have moved a big step forward. Hardware is now ready, and so is the Arduino code for RPM-measuring.

Tested up to 25000 rpm (that was scary...) and works like charm at least what I can see.

Ability to use one or more magnets, ability to set gear-ratio so RPM shows for example headspeed etc.

All I need to do is to put the jeti-code around it in order to make it complete.

I'm also studying the possibility to set amount of magnets and gear-ratio from Jetibox but cannot promise that.

[Baedarlboo]

Originally Posted by TeroS

It's been long due but this project have moved a big step forward. Hardware is now ready, and so is the Arduino code for RPM-measuring.

Tested up to 25000 rpm (that was scary...) and works like charm at least what I can see.

Ability to use one or more magnets, ability to set gear-ratio so RPM shows for example headspeed etc.

All I need to do is to put the jeti-code around it in order to make it complete.

I'm also studying the possibility to set amount of magnets and gear-ratio from Jetibox but cannot promise that.

Now that's exciting!!!

[TeroS]

Hall Sensor for 5€ is done

Works up to 65535 rpm, looks to be very stable and accurate.

Ability to set amount of magnets and possibility to set gear-ratio if you want for example head-speed instead of motor speed.

Schematic & partslist & code & how-to hopefully out during this weekend

[Baedarlboo]

Originally Posted by TeroS

Hall Sensor for 5€ is done

Works up to 65535 rpm, looks to be very stable and accurate.

Ability to set amount of magnets and possibility to set gear-ratio if you want for example head-speed instead of motor speed.

Schematic & partslist & code & how-to hopefully out during this weekend