Thanks for the letting me know the etiquette of the forum, I really appreciate it.
I found this guy's twitter and apparently he makes nano motor drives?
Do you think this would be a solution?!
Thanks for the letting me know the etiquette of the forum, I really appreciate it.
I found this guy's twitter and apparently he makes nano motor drives?
Do you think this would be a solution?!
This is precisely the size that would fit inside the sphere with the stepper motor.
You would also need power supply and a uC , and pretty deep pockets too I'd imagine.
Hi,
How big is the sphere?
How heavy will it be?
Do you know if that small stepper cam rotate the sphere, Nano and Batteries?
What is you overall construction idea.
Can you please post a drawing of your basic concept.
I fear that stepper will not have the torque to rotate all that mass.
Tom...
Hi Tom,
The Obsidian sphere has 19mm. I am carving out the inside to fit the motor you saw, this Pico board ( https://mellbell.cc/products/pico ) and how many cell batteries I can fit and need.
Essentially I wanted it to look like this:
But now I will probably need more space for the pico board and I will probably have to re-think of a way to fit cell batteries that would have an easy way to replace them. ( I'm skilled enough with 3d modelling that I could make this happen )
It will hang from a metal necklace, to be wearable.
Welcome to the forum! You will find yourself in good company with numerous morons; many will proclaim differently, however.
I have not reviewed these results, but one or two look promising from the condensed description:
https://www.google.com/search?q=arduino+moon+phase+servo
Ray
It seems to me a great challenge to assemble all this electronics, mechanics and power supply in a sphere of size Ф19mm. Maybe it's a good idea to design your own PCB board. Because you will be using a stepper micro motor, you can try to operate it without a driver. I tried with ATmega88 to drive a stepper motor from an old FDD and it worked. Because the current from the pins of the microcontroller is small, the motor cannot move very fast, but for your purposes this is not necessary. I don't know if it's a good idea but you might consider using a super capacitor instead of batteries. I think you will also need RTC (real time clock like DS3231) to keep track of time.
Not with a stepper whose windings draw 260 mA. That is way beyond the capability of an ATmega/ ATtiny.
"Worked" may be evanescent. Not the sort of "worked" that we accept here. Note: These small stepper motors are due to their size, very inefficient. A larger stepper may be just sufficiently efficient to actually move before the microcontroller dies.
Because the current from the pins of the microcontroller is small, the motor cannot move at all.
I do know.
It clearly is not.
I wonder, how many steps per revolution does the micro-stepper have? If it's not many, you might have a problem with the inertia of the load.
evanescent... Such a beautiful word!
Now I'm thinking I might need 2 of these
plus the pico the motor and batteries. Maybe then it will work? and maybe this RTC ?STEVAL-ISB68WA - Qi-based wireless power receiver reference design for wearable applications up to 2.5 W using STWLC68 - STMicroelectronics
The challenge will be fitting all of this inside but I think I could get a slighter bigger sphere... 24mm and cut it in half and carve it so it all fit's inside.
Or this?
Alternately, when used to refer to directly driving said motor from the microcontroller's output pin, if may refer to that incandescent puff of magic smoke!
It's a good idea to build an oversized prototype first to make everything work perfectly, then miniaturize it. Especially if you haven't built a lot of miniature electronic devices before.
+1
Ray
If the stepper is bipolar, maybe it's just too depressed to move.
So what is the winding resistance?
Less than 10 Ohms on each coil.
So you are connecting your ATmega pins to essentially a dead short?
Is that a good idea?
According to popular opinion, this is very bad idea and would lead to the burning of the microcontroller. I am curious and decided to try in practice what the result will be. I tried several ATmega8, ATmega88 and ATmega328 and all survived - in DIP28 and also TQFP32. In theory, such a connection should have a very large current and burn the microcontroller or at least the connected pin, but in practice it turned out that the current is limited to less than 45mA (at least with ATmega8 I measured it between two together directly connected pins from diferent ports, one with high potential and another with low potential). Very often when I do a quick test I connect the LEDs directly without current-limiting resistors and I still don't have anything burned out. However, I do not know how this will affect the lifespan of the microcontroller.