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


I am confused Peter it will have to position the sensors on the right hand on the other side of the printed circuit thank you sorry !


I am confused i am recontroling my PCB assembly and placement constraints in the accordion

I made a small photo with my iphone sorry ! i look your fzz

I must have the sensors on the opposite side on the same space on the circuit board


peter, if it’s too complicated I will try to mount the circuit in the same direction but the distances between the magnets and some rods will be more important (magnetism), the stems are not at the same height and not the same length I need find the ideal location to fix the circuits (about 3 cm ) and glue the sensors . But this is perhaps more easy for the magnets ???


I’m a bit confused about what opposite side means. The sensors need to be on the bottom of the circuit board but the same way Pins 1 2 3 (that is easy) or pins 3 2 1 (i.e. the current part rotated 180 degrees). At this stage it is easy to make changes, after boards are ordered it gets more expensive (because you need to order new boards). I can flip the senors 180 degrees fairly easily if that is what you need.


On the assumption that you needed the sensors reversed (as that makes sense right to left) I did that in this sketch. Unfortunately I also broke routing which I need to fix. But for the purposes of positioning the senors this sketch should do fine. I have expanded the length of the pcb to 340CM. You can adjust that to what you need by selecting the grey background and changing the width in Inspector. It is getting late here, so I’l continue this in the morning.

accordion-left-hand-Sketch.fzz (187.0 KB)

I also assume that we are considering the right hand board done as it stands? You don’t need changes to the sensors? Or if the left works out you will make adjustments to the right hand board as well?



Peter, thank you for all this work! It is very good .
The last sketch changes the left hand ??? , 1 2 3 why not? I have to control the most favorable pole of my magnets
My last question was for the circuit of the right hand:
321 or 123 why not? but the most important question is: is it necessary to have the sensors with the right hand at the top as on the current circuit or at the bottom in the same order D1 to D 49 with 321 or 123. There are actually two questions.

one for the sensor and the fixing of the printed circuit (where and in which direction?) for the right hand
another for magnetism 123 or 321? I try in vain to make photos with annotations with photo draws but it does not record me correctly my photos !!! thank you for all


OK I think I understand the issue, it isn’t the pin order that is wrong but the orientation of the sensors on the left and right boards, and currently the right side is wrong. If I understand correctly the boards need to look like this:

So the right hand board needs the sensors on the bottom of the board rather than the top where they currently are and the left side needs the sensors on the top of the board as they are now. I think the pin number order matters because the sensor is more sensitive one way than the other, is that correct? If so are the pin numbers in the sketch above correct or do they need to be the other way on one or both boards?



Good evening, Peter, Yes yes !!! I think you understand; we do not change the order of the pins always 321 for both hands. the left hand has to go back to where it was at the beginning and I confirm to you after having opened my accordion today that for the right hand you have to put the sensors down with the pins in the same order 321. I think we understand it !!! I always try to make you a sketch more accurate but it’s difficult I do not have a good software and it bug!



OK here is the latest copy of the left hand sketch, with the sensors back where they should be and the pcb extended to 340mm ready (I hope) to have the sensor positions changed. Now I’ll work on fixing up the right side to match the sketch above.

Edit: replaced this because I missed some labels in schematic:

accordion-left-hand-Sketch.fzz (183.3 KB)



Good evening peter thank you for your work. The total dimension is 360 mm (“2.75 mm - 305 mm - 2.75 mm”). The sketch looks correct. I will look at the sensor positions, make an the circuit board impression and paste it on a cardboard. How to make the impression in 1x1? ( jpeg ?) thank you peter


While I haven’t tried to print out circuits before, just selecting file->print from Fritzing while in pcb view appears to have printed the pcb at 1 to 1 on my laser printer (it printed on two pages as it is so large but it appears to be at the correct scale).



Good evening peter, the diagram of the left hand is wrong, the sensors are poorly distributed. I made a montage with a ruler and I spotted the distance between each sensor, the pin 2 serving as marker and axis. I can not handle the software correctly! sorry but is so difficult for me .


OK, I’ll change the left hand to what match this and repost it in a while. I’m currently working on making the right hand board both reversed and narrower by moving the traces, but I’ll switch to left hand first.

Edit: here is the left hand board with the sensors moved to the positions you indicated. Give it a try and send any corrections.

accordion-left-hand-Sketch.fzz (183.7 KB)

As well just before I give up for the evening, here is a partially routed version of the right hand side in case you want to reposition the sensors on that one as well . I think it may be possible to make the board a bit narrower than the current 3cm if that would be helpful as well.

accordion-right-hand-Sketch.fzz (162.5 KB)



Good evening, peter, I only looked at your last message right now.! So I did not check anything. But tomorrow I’m looking at the two sketches. This is fine if you can reduce the width to 2 mm, 2.5 mm. I will take all my measurements with a new rule graduated to 0.5 mm! I need to make mount brackets aluminum to see exactly how I can fix the two circuits. Keep the original version of the right hand! I am always looking for the best position it is very difficult and cramped !!!

thank you for your work and your skill philippe


here are the measurements for the right hand I print today both diagrams and I control


here is the right hand we must correct the measures thank you


here is the latest version for the left hand is better but it’s not yet that thank you. I think that to position the most correctly the sensor must be put at the top of the screen the ruler and take as a reference the axis of the pin 2 sensor U1 and move as each sensor with the right button of the mouse. thank you


I can not do better for the right hand here is the rule


For thé left hand


I’m going to try and import the jpg to an svg so that I can have the jpg superimposed over the pcb layout to be able to move the sensors to match the magnets. We will see how that goes …