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


It’s a bit hard to follow what’s going on because the translation isn’t great, but I think we need the spacing of the magnets. Then again there is a thing with switches.

I read 305mm, then something 335mm, it all gets confusing. We really need a mech drawing.


305m is the max size of the board, it is going in to a space that is 335mm long as I read it. The extra space has something else in it I assume. I’m redoing the small signal diodes I did a couple of years ago because they are needed here, then I’ll try a minimum space board with 49 hall effect sensors and see how long that is.



OK, I did about 25 (a bit more than half) of the sensors on a 30cm by 3CM PCB. With half done we are using less than half the board space so fitting 49 sensors in to 30Cm shouldn’t be a problem. It is currently late here so I’ll continue this tomorrow. If you can supply the desired spacing between sensors it is easy to move the sensors in to the position you want them (and the leads will allow you to adjust them one way or the other for a short distance as well.)

here is the sketch with half the sensors done:

accordion-Sketch.fzz (42.6 KB)



You can box copy blocks of parts - you have to start the box in a blank area and not on the BB -, hold CTRL and click on the BB to deselect it, and then just copy paste and move that block of parts. If you want the parts in the other views to move in an orderly pattern you have to line the parts in a row before hand, which you have done, and it will copy the parts in a row in the other views when you copy the BB parts.

I don’t know if the Hall SCH is the best for packing 49 parts in a row, maybe something more compact.

I personally wouldn’t even do a BB view, only a SCH and PCB, because it just seams like more work for something that will not be made in real life.


Wish I’d read that before finishing this :frowning: , I tried selecting a bunch and copying but was on bb and didn’t use cntrl and it didn’t work so I did it manually.



OK looks like it will fit fine, here is the complete 49 sensors on a 30CM wide pcb at minimum spacing:

as you see we have room at the end if needed. So to go forward I need to know what spacing between the sensors you would like and how the 8 connections to the mega are made. The choices would look to be a 8 pin header (which provides either holes for wires or a header to plug a cable in to, or an 8 pin dual row header to take an 8 conductor IDC ribbon connector cable. Which would you prefer? Also where do you want the connector, left end, right end, middle of the board or somewhere else. All the parts need to be placed before routing the pcb. Does anything else (such as the switches in the schematic) need to go on this board as well or is it only the hall sensors and the diodes.?



Bonjour peter , je vous joint une photo; Sur cette photo il y a la photo de mon circuit left hand du capteur de 1 à 49 sur 300 mm exactly with the hall effect sensor just in face of the black trait on the white réglette this is my matrice because every 49 magnet are stick on la soupape do do # ré # mi …look the second photo . For les wires , look the schéma tom scarff vers la arduino mega 23 25 27 29 31 33 35 37 39 22 … with X2 : 32 30 26 24 22 pontés entre eux and for push button 4 . I think qu 'il faudrait un connecteur au centre de la carte qui reprenne le maximum de wires en nappe sauf les interrupteurs et la broche midi . thank you peter


The magnets are on every tige en fer actuionnant la soupape ( do do# ré mi ;;;;;;;;;;;;;; ) you unterstand

49 hall effect sensor for 49 magnets for 49 notes message midi thank you


Merci peter pour votre aide , je ne sais pas choisir le type de connection ,le brochage ,

Les diodes D1 à D6 reliées au fil 23
les diodes D7 à D12 reliées au fil 25 …

il y a environ 35 wires
à souder sur la carte arduino 2560


Is it 300mm or 305mm from the centre of magnet 1 to the centre of magnet 49. The measurement has to be exact.

Est-ce 300 ou 305 mm du centre de l’aimant 1 au centre de l’aimant 49. La mesure doit être exacte.


Bonsoir, c’est très difficile de vous donner une mesure exacte la seule mesure exact elle est entre la
1 ière tige et la 49 ième tige . Je vous envoie un petit croquis merci pour votre aide philippe


Je pense qu’en prenant la pin 2 du capteur à effet hall comme repère avec mon croquis on à pour la main droite 6 mm et pour la main gauche 7 mm entre les capteurs . Mais supports pour les magnets , les tiges ne sont pas exactely à la même distance .

thank you


I’m a bit confused because 49 Hall sensors at 7mm is 336mm, but the gap between posts is only 300mm.

Right-hand is 288mm from pin 2 of #1 A3144 - to pin 2 of #49, so is ok.


305 mm du centre de l’aimant ça me semble très correct merci peter


eh oui je ne comprenais pas moi non plus !!! avec un espacement à 2.54 mm !!! je vais me coucher merci


I suspect we don’t need exact measurements except for the maximum length of the board. It is just that if some particular pattern would make it easier to do, before the board is layed out is time to do that. I’ll space the sensor pads out across the length of the board. With long leads on the sensors you should be able to tilt them a bit one way or the other before soldering them to fit them where they need to go. it should also be possible to make both a dual row header (looks like about 20 pins all told) and a row of single pads at the back / center of the board so you can use either ribbon cable or wires, which ever works best. All the internal wiring will be traces on the circuit board so it is only the connections to the mega (and power and ground which don’t show on the initial schematic) that need pads.



Cool peter it’is very good


Péter je vais ouvrir l’accordéon et contrôler à nouveau les dimensions merci pour tous


I suppose it doesn’t have to be as good as I’m making out - I’m a former machinist -, and if the furthest apart magnets spacing, ie 1 to 49, is greater than 300mm, they have to be offset on the legs anyway.


Peter je vais positionner la carte arduino sur les sommiers à l, intérieur du soufflet de l’accordéon , rallonger les wires de la prise midi jusqu’à droite derrière mon clavier de la main droite ainsi que les wires des 4 push buttons contrôlant les changement d’octaves " up and down "

push button