www.megadrum.info

Hall sensor A1302 (http://www.allegromicro.com/~/Media/Fil ... sheet.ashx). Datasheet is attached.

Magnet (http://www.tme.eu/en/katalog/?idp=1&sea ... rameters=1) is type neodymium, Body dimensions Ø8 x 15mm, Material NdFeB, Residual magnetism 1150mT.

I tested the above components and they were working perfect. Magnet was felt from about 40mm.
I discovered something wrong, the Hi Hat pedal input jack (J1 in "input sockets.pdf") had a mistake, wires going to pin 1 and 5 of pads connector was inverted.
So I made the correction and test again. This time happened what must not happened, I connected the hall sensor wrong, that mean with pin 1 (VCC) to GND or in another wrong way, I do not remember.
Now I can not make the system to work again.
I bought another hall sensor, and nothing.
Is possible to damage something?
How to test if everything is well with ATMEGA?
Please help me to debug the results of my lack of attention.
I measured the tensions on Hi Hat pedal female input jack jack (J1):
- sleeve - tip voltage is +5 V (this is VCC connection for sensor)
- sleeve - ring voltage is +1,63 V (this is VOUT coonection for sensor)
After connecting hall sensor:
- VCC is 4,25 V
- VOUT is 0,68 V

What is not working?

The hall effect is not working.
I do not understand very well the functionning of Switch "HiHat Pedal Select". It is for selecting Pot or Foot switch and must be used in parallel with Alt Input from MDM?

HiHat Misc:

Levels:


Strange behaviors:
- When High Level is 500 or something over 150, low level is for example 10 and I put low level = 150 when send to MD I hear the sound of HH Closed (I have VTS Host with Addictive Drums).
- When Low level is 120 even if high level is 800 or 200, on the MD display (Big VU meter) I have only 5 lines in left side.

I tried with a lot of combinations of low and high values, the effect of hall sensor (when the magnet is practically in contact with sensor) is maximum 5 lines on MD display.
I tried also with Alt Input checked.

And I am so sorry that I did not write down the values when I got first time the perfect effect.

Looks like you're trying to configure it at random. You should really read http://www.megadrum.info/content/hihat-pedal-settings and in particular about Type, AltIn, LevesAuto, LowLevel and HiLevel.

Please Dmitri tell me which is position for high impedance pedal? 1 or 3 in the image bellow.
Thanks.

Alternative (high impedance) HiHat pedal input is on pin 3. Pin 1 is for HiHat pedal power (ring). You could read this information from the schematics in viewtopic.php?f=3&t=266 from the same place where you got the Inputs sockets schematic.

Thanks Dimitri, I was speaking about pin 1, 2 and 3 of the HH pedal selector switch (sorry for not clearly specifying).
Anyway now is clear:
- pin 1 of switch SW1 is for low impedance pedal (pin 5 of pads connector)
- pin 3 of switch SW1 is for high impedance pedal (pin 3 of the pads connector)
I tried to measured the electrical resistance of the hall sensor with my multimeter, I do not have something else, and shows like this:
- between pin 1 (VCC) and pin 2 (VOUT) --- 1,38 kohm
- between pin 2 (VOUT) and pin 3 (GND) --- 18,5 Mohm
- between pin 1 (VCC) and pin 3 (GND) --- 18,5 Mohm
So I assume that it is high impedance.
Correct me please if I am wrong.
I shall make again tests with the settings from above.

You cannot measure output impedance on hall effect sensor with a tester. Hall effect sensor based pedals are low impedance.

dmitri wrote:You cannot measure output impedance on hall effect sensor with a tester. Hall effect sensor based pedals are low impedance.

Thank you for this info. I shall test it using low impedance settings.
****************
After hard work without any result, no reaction like hall sensor was dead, being also so late, I solved the problem.
I looked wrong on datasheet, I was looking to LH package (wrong) and I have UA package and for UA package two pins are reversed.
This was all. Because of this stupidity I lost almost all night.
Is working like a charm.
My settings with sensor A1302 and 2 magnets MAGNET NDFEBB (magnet diameter 8 mm, magnet length 5 mm, total length for 2 magnets 30 mm) one after another.
- HH Pedal Switch (SW1) - Low impedance
- Alt input - checked
- Low level - 40
- High level - 450
- Curve - LiniarCustom1
- magnet travel, from the moment when first line from MD display disappear and till when the closing sound is heard, is more than 30 mm and I think that this travel is absolutely satisfactory.
- minimum distance between magnet and sensor, when completely closed, is 3 mm, enough for protection of sensor.

Wiring diagram:


In this moment I am satisfied, MegaDrum work as designed by Dmitri, all functions are up.
Now I have to start the second part of project, building pads and pedals.
Thank you Dmitri for this nice project.