chaterronySo, summer is ending and the new PCB arrived after the vacation. The Hall sensor works pretty well. However, the speed is an issue at the moment. Not that I want to run the handles very fast, but the max speed (if both are running at the same time) is roughly 9s/turn. And in addition, when one handle is running at constant speed, it changes speed when the other is accelerating. Seeing all the other attempts on the internet, I doubt that the ATMEGA328p is at his limits. But what is then the reason???
Video can be seen here:
And yes, I did an error on the PCB, therefore I had to handsolder a little bit ;-) Looking for half a hour on the PCB prior to manufacturing is obviously not enough...
Have a good start of the week!
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Hello Arne
PCB design has an error for the I2C selection switch. But this is not a big deal. I have uploaded the PCB design, but be aware of this error! :-)
I used the following components:
Hallsensor: OH49E: https://www.aliexpress.com/item/49E-Hall-element-OH49E-SS49E-Hall-sensor-Hall-Effect-Sensor/32433449139.html?spm=a2g0s.9042311.0.0.27424c4d02L0n4
Magnet: dia3mm, length 1mm: https://www.aliexpress.com/item/10-50-100-200pcs-3-x-1mm-Powerful-Super-Strong-Rare-Earth-Neodymium-Disc-Magnets-3x1/32957114317.html?spm=a2g0s.9042311.0.0.27424c4d0JrBqR
The stepper can be driven directly out of the ATMEGA328. The coil resistance is 275Ohm, which results in 18mA power consumption (plus spikes of course). As I use the microstepping library of @Gijs Withagen (see the corresponding chat linked below), there is no need for another hardware.
As a master I use an ESP32, see the code in the files. This is what is running in my prototype with 3x3 motors.
Link to discussion: https://hac.io/m/276809
good luck, and share what you created :-)
Olivier
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Hey there - super nice to have some ongoing reports about your project. I am actually pursuing a very similar approach to you and was thinking whether you could share version 2 of your pcb.
Also, whats your approach driving of the stepper motors - do you think clamp diodes should be necessary? Have you measured the current through coils? I am still thinking about utilising a dual-stepper-driver ic.
also - which hall sensors are you using? what size of magnets? currently i'm using a oh49e and 1x2mm magnets...
thanks for any answers :) cant wait to clean up my code and put it out there. what are you using as a master device?
best,
arne
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