Conception de 2 circuits imprimés avec capteurs à effet hall , et une carte arduino , pour un accordéon


I will try to find the way to position the mounting holes on the circuits boards but it is very difficult because there is little space and i have to make différent aluminium fixtures to the attachement aréas. If the circuit board is 3 cm wide a single fixing holes on each side will suffire. I calculate all that and come back to you. Thank you for your expertise philippe


Like this -

I would be surprised if anyone makes a part with long legs anymore.
Here are 400 TO-92 package Hall sensors you can look through. You would have to check the datasheets to see if anyone makes a long leg TO-92 package.

You can cut the corners of my wider PCB to make it fit, but I think you will need the extended centre section because Hall sensors have short legs.


I think we can do the 2 circuits board for the right hand and the left hand of the same lengh and position the sensors in the way because there is not much difference between each sensor about 6 mm or 7 mm. THank you , we’ll discuss it again later


the rods on which the magnets will be glued have a spacing which varies a little less than 1 mm, especially on the right hand, moreover the rods are not exactly at the same distance from the magnet, it will be necessary to adjust each magnet individually to ensure the connection noon on off for the left hand it’s simpler the gap between each rod and the same is the distance with the magnet and more regular for the midi link on off


the printed circuit must be 3 cm wide the connection tracks of the sensors must be at the end of the circuit on my diagram it is not necessary that the tracks 5 volts or 0 volts is at the edge of the circuit upwards it is the sensor that has to exceed the card I bought the sensors 200 sensors now I can buy other sensor with longer legs if necessary here but I solder by putting a bend at the end



Hello Peter you use what software to mark text and arrows on your drawings and also for pictural . I want to scratch the last sensor is not necessary on the card thank you sehr gut mein freund !


hello peter Here is the picture of my Arduino interface it is provided with small connectors of red color.


I agree with @Old_Grey on this one, I don’t think we will find another hall sensor with long leads in a smaller case these are already pretty small. As well you have used these (at least I think you have used these) and they work, a new one may not. So I’d advise using these ones.

That’s good, at present for the right side (at ~6.1 mm spacing on the sensors) it takes 296mm from the start of the first sensor case to the end of the 49th sensor case so you have a few mm left over. Given the long leads on the sensors you should be able to place move them a bit left or right to line up if you need to. I’m going to finish up connecting schematic for the right hand board and then I’ll clone that and move the sensors for the left hand board. If you load the accordion-Sketch.fzz file in to fritzing in pcb view you can look at and measure (and change if you like) where the sensors are:

Here sensor 49 is selected (by clicking on it) and its position shows up in the Inspector window on the bottom left. X followed by Y in mm (circled in blue). If you click on mm it will cycle from units on inches to mm to px (90dpi I expect). If you change the numbers in Inspector the part will move to the new position so you can custom position each sensor if you wish (if that would be useful). To see the spacing, record the x coord of u49 then select U48 (the next sensor along) and subtract its x coord from that of U49 and you will get about 6.1mm (it varies a bit from sensor to sensor by a little bit depending on the snap)


If you don’t want mounting holes, that is fine, it is just that it is easy to add them to the pcb and saves you from having to drill them in the finished board. It isn’t a problem to leave them out if that suits you better.

I use Snippng Tool on Windows (it is in the accessories folder). You pull select an image by pulling a box around it, and it creates an image. Then it has a pen tool in the tool bar, where you can set the ink color (default blue) to red and draw on the drawing. Once that is done you can save the image as a png or jpg image for upload.



Good evening Peter, good old gray! , I’ll look at your work, if you have to buy other hall effect sensors, connectors dupont no problem! I bought a lot of things (200 €) by counting the arduino card, magnets in Germany at super magnete, 200 sensors in China I used about 55, wire, connectors for arduino in China! . small circuit boards to double-sided! It is not a problem however to buy other sensors with longer legs I could actually orient them a little more easily. How many wires will be connected to the arduino card? 20? there are also some that will be looped between the printed circuit of the right hand and the printed circuit of the left hand: 22 24 26 28 30 32 Thank you for your work it’s great!

For fun !
For information here is the table of correspondence between a note of music and the midi coding which is affected to him. The correspondence with the diagram of Tom scarff.

For the keyboard of the right hand:
From (Mi1) E1 to (Mi5) E5 are midi codes (28 to 76), sensors SW 50 to SW 98 (tom scarff)
For the keyboard of the left hand:
From (Sib1) Bb1 to (sib5) Bb5 are midi codes (34 to 82), sensors SW 1- SW 49. This makes it possible to understand how the circuit boards will be positioned, from low to high, from top to bottom for the keyboard of the right hand and from low to high, from the bottom to the top for the keyboard of the left hand. . In addition, the push buttons

will allow to go down or up the octaves

hihihi !:rofl:


You might be able to set a different specific grid and just snap them in place.

If you can’t get long leg Hall sensors I suppose you could solder extensions to the 300 legs. 30mm might be too long for modern thin wire legs, because of overhang vibration, so soldering thicker legs might help.

EDIT - maybe a soldering jig.


small precision peter and old grey i could if necessary shift the magnets for the sensors that will be installed on the second line of welding good night


I asked Tom Scarff to give me a sensor reference with longer legs ! Thank you gute nacht


If you can’t get them, maybe this is an option if there is something in the way of a wider PCB.


no, there is only one meaning !


Hello peter I would like to put a pressure sensor inside the bellows of the accordion can I help to change the program I have the source code of my card Ino source file is a question ? I look at today for the sensors and for the holes to fix the PCB thank you for your coopération philippe


hello old grey , réponse : 305 mm in the center of the magnets thank you


a friend working at Maugein accordion send a photo of a sensor that is 20 mm long and the reference is not on the Internet


Good evening Peter good evening old gray. I have a big problem! It is the setting up of the magnets on a rod about 2 mm thick, more magnets are very powerful and they attract each other. It is impossible to set up apart from the solution to find a plastic envelope for each magnet as for small cylindrical magnets that we stick on the fridge. I do not know how do midi interface makers, I believe the limex company uses this system. For the holes in the circuit boards we will see later that’s not the problem today. I will use the connectors dupont buy crimping pliers, and watch again and again to pass the wires. but the big difficulty is real how to fix the magnets. Thank you for your collaboration in the manufacture of 2 PCBs


I found the solution, plastic pegs but I have only two perfect chevilles at the perfect house that I can also fixeon the side for .isolate this to the magnet next to it