hall sensor for hihat input wiring diagram.

[mprinz]

Hi Rob, hi Polyphonics, hi to all Hall sensor users,

when thinking over magnetic field strength and symmetry:

Did you try different geometries of magnets, meaning shapes and orientations?
Discs vs. cubes vs. rods ...

[dsteinschneider]

I have a hard drive magnet mounted on the end of the rod moving down until the tip of the magnet is just a mm away from the the A1302 sensor.

It's playing very well but I'm interested in learning more. When I calibrate my green bar is rather narrow. Since the movement of the hi-hat is realistic I assume that a narrow range in the bar is fine

[mprinz]

Hi,

Rob has to correct me...

I wanted to use an Arduino Uno ore later a Teensy as DIY module and I read and tested all that piezo, diodes, programming stuff.
I was already struggling with the reading of the piezo signals. I just saw the code of other DIYers, and ... yuuur .
BUT THEN I found the eDrumIn and I quited.
With the eDrumIn transient graph, the codes from other good edrum projects got clearer to me...
I just got a Millenium MPS-850 module ... So, I didnt know the paramters scan time, hold, and decay ...

Anyway...I get off the track:

The green bar is a voltmeter.
A narrow green region, for me, that means your contruction leads only to a small change of the output voltage when moving the hats.
That's why I choose a hall effect sensor with a V_out of 4.5 with a supply Voltage V_s of 5 V. I think thats what we have on the edrum, since
we can use USB as power supply.

So, "wrong" sensor, wrong orientation, did you try to flip the magnet (I actually dont know other V vs. Gauss specifications, only from the Honeywell SS49 series They have a linear response for positive and negative gausses) or wrong distances but the magnets from a hard drive should be quite strong.

[Polyphonics]

The green bar is a voltmeter.
A narrow green region, for me, that means your contruction leads only to a small change of the output voltage when moving the hats.
That's why I choose a hall effect sensor with a V_out of 4.5 with a supply Voltage V_s of 5 V. I think thats what we have on the edrum, since
we can use USB as power supply.

So, "wrong" sensor, wrong orientation, did you try to flip the magnet (I actually dont know other V vs. Gauss specifications, only from the Honeywell SS49 series They have a linear response for positive and negative gausses) or wrong distances but the magnets from a hard drive should be quite strong.

Could you link us to any of these sensors that you think will do better? I had also used the hard-drive magnets but also tried out some rectangular and circular ones. I found the rectangular ones worked best (similar strength to the hard-drive magnets). My green space is about the same range as the pic above.

[mprinz]

I got them a few days ago, and got stuck with other crap, so can't say actually how they work.

https://sensing.honeywell.com/SS495A-li ... sensor-ics

I have two of the SS495A here.

And what magnets?

[Polyphonics]

thanks man, I've ordered a few of those from Farnell

also, the magnets I use are N52s rectangular (3 together), my harddrive ones will be put to use in my shaker pedal I'm creating.

The angle; I held the sensor in place and tried moving the magnets around to see what worked, I use one of the flat sides.

https://www.ebay.co.uk/itm/Strong-Magne ... 2749.l2649

[mprinz]

Hi,

I found out that 640 Gauss are 0,064 Tesla (10.000 Gauss = 1 T). And a regular horseshoe magnet got
approx. 0.1 T.

So, I assume that we wont need such strong magnets. I dont know. That's my guess.

Ahhh, look, it's denoted in the description "Surface flux 230 mT" that's 2300 Gauss.
So, it shoudnt need to come that near to the surface to avoid an early saturation resulting in a CC value of 127 when the
pedal is not fully pressed. Thats, what Rob wrote a few days ago:

If you set the magnet off to the side slightly, the distance from the magnet to the sensor will change exponentially as the hats come down, thus giving you a close to linear voltage response.

Anyway, we havent got a Gaussmeter, so it's gonna be try and error.

[mprinz]

Awww, now it doesn't work ...
I set it up to test it with a 5 V supply voltage and ...tadaaaa... ok. As expected.

Then connected the hall sensor to a TRS jack and then plugged in a stereo TRS cable to
the edrum... nothing.

Again checked the sensor, working ...

eDrumIn ... not working, why?

I noticed you use 3.3 V, anyway I should get out any signal.
I used the expression pedal mode, so you apply a voltage to the ring? (in straight mode)

I think I'm going to order part number SS49E because it's low voltage operation means that it can be powered directly from the eDRUMin pedal input. Are most users powering their hall effect sensors externally?

I understand it like the topic starter didn't use an external voltage, but aaahhhaaaa...
Now, I ... I was wondering ... You said the polarity doesn't matter since sleeve is gnd.
It doen't since using an external Vs and connect it like a simple hihat controller, ok?

Hm, it's late, I have to sleep!

[dsteinschneider]

Late here too. I just caught up on this thread. My ED10 is plugged into a powered USB hub. The Hall effect DIY pedal I made is only getting voltage from the ED10 pedal input. I'm happy with it, plays just like a real hi-hat but I'm building another smaller kit for jams and will experiment with the voltage when I build that one.

[mprinz]

How did you setup the connections. Like denoted in the thread, didn't you?