Sometimes it’s helpful to realize the truth that there is no spoon. At least, not with [Ronaldo]’s automatic self-stirring mug. At first it was just a small propeller in the bottom of the mug that turned on by pushing a button in the handle, but this wasn’t as feature-rich as [Ronaldo] hoped it could be, so he decided to see just how deep the automatic beverage-mixing rabbit hole goes.
The first thing to do was to get a microcontroller installed to handle the operation of the motor. The ATtiny13a was perfect for the job since it’s only using one output pin to control the motor, and can be configured to only draw 0.5 microamps in power-saving mode. This ensures a long life for the two AAA batteries that power the microcontroller and the motor.
As far as operation goes, the motor operates in different modes depending on how many times the button in the handle is pushed. It can be on continuously or it can operate at pre-determined intervals for a certain amount of time, making sure to keep the beverage thoroughly mixed for as long as the power lasts. Be sure to check out the video below for a detailed explanation of all of the operating modes. We could certainly see some other possible uses for more interesting beverages as well.
24 thoughts on “There Is No Spoon; Automatic Self Stirring Mug”
Why 0.5 microamps ? the unit of energy is watt, right ? why using amp ?
because the current is the thing thats fixed, not the power. IIRC, the chip takes basically the same amount of current at different supply voltages, and the supply can vary quite a bit, probably 2.7-5.5V, or even more (I thnk the same is true for most microcontrollers). In a lot of cases, this current will actually increase with the voltage, for not really much benefit in performance (you can maybe go up to higher cpu speeds).
The unit of energy is Joule
Unit of energy is joule or erg.
Watt is the unit of power or energy / time.
The obvious next step on this is a combination heating/inductive charging pad, and replacing the batteries with a supercap.
And make it send email.
A clever hack would be to harvest energy from the heat,
we could call that “convection stirring”
How to create a large enough temperature deferential, without cooling the drink too fast.
I still think the, chemistry style, magnetic stir bar would be great for this.
Maybe the stir bar could be inductively heated to keep the drink at the correct temperature. A small thermistor with a small square of heat sink and an led or oled with the current temperature would be good (:
A good idea with an external power supply. Perhaps it would work if you use a 6- coil arrangement similar to the flat brushless motors used in floppy drives. Then you can overlay two rotating fields of very different frequency:
One with low frequency to turn the ferromagnetic stir bar and at the same time in the same coils one with much higher frequency for hysteresis heating of the bar.
If that does not work out, then you could use a second coil with different orientation for the heating, so they are decoupled.
Or remove the motor from the cup and have the motor spin a magnet in a coaster. Then in the cup have a magnetically coupled propeller.
This could be USB powered and be directly controlled by the computer.
A small program could be written to accept input from the mouse and the stiring action controler by the movement of the mouse.
Yup, magnetic stirrer, it’s pretty common in labs. Would be much easier to clean than one with propeller inside a cup. Also leak-proof.
Magnetic stirrer with motor and controller embedded in base. USB rechargeable battery in the base and capacitive sensor in handle. Set it up to stir automatically for 5 sec every time its picked up and held or for 30 sec with a quick touch.
But is it really worth the added chance that you might one day inadvertently swallow the magnet?
If the driving magnet is in the base of the cup, the stirring magnet will stay at the bottom.
You could glue the whole thing to the bottom of the cup in a free-spinning way (with something food-safe, obviously)
…or a nice guard over the propeller.
I take it that black coffee is not an option?
Good design process given your parameters ;-)
No, it isn’t.
But I don’t stir the milk, if you add cold milk to (too :-) ) hot coffee it mixes well. I only stir, if I use sugar (rarely).
Could use it to make a starter for beer brewing and related activitites.
nothing better than a wonderful coffee stirred with a greasy motor, that’s how you drink it in Portugal.
Very hard to clean, tea makes it worse. The bushing needs to be lubed with veg-oil every time it’s cleaned. Oil taste. Go mag.
I always swish everything together in a one third full cup then add water quickly down the side. Swirls top to bottom…perfect mix, no spoon and cleanup.
But you have watered down your (hopefully) good coffee. :-(
Has long been invented:
1. Strong whirlpool. Still drinks shall row do you use the spoon?
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