I want to do this project :
But unfortunately i can't find what HALL sensor he used.
I thought maybe using instead Ultrasonic Distance Sensor to know the distance to my object.
I'll be happy to get any advise on this matter. (like, don't use the distance sensor because ..., or you can buy this sensor which will be more usefull...)
A couple of sensors can be used. Why don't you ask in the mentioned thread, where people obviously made it work already?
A ultrasonic distance sensor will not be accurate enough and will not update fast enough.
Just use any linear Hall effect sensor.
Oops I replied in the other thread.. use any linear hall sensor like A1318, A1319. It might require some interfacing, not sure if direct analogRead() is sufficient.
Don't think ultrasound works, one reason is you need to detect tiny movement of the magnet to hold it like that
I can't see any data on that link. It is always a risk buying stuff without the data sheet.
Look at the data sheet of the A1318 and A1319 for the magnetic sensitivity of those devices, then you know what you are aiming at for a replacement.
The schematic in the first post says "A1306" which is an Allegro Microsystems part number.
I found this hall sensor :
I couldn't find A1318 and A1319 in aliexpress
Well you should have googled for datasheet, "AH3503 linear hall sensor"
A3503-Datasheet.pdf (1.22 MB)