Hackaday Prize Entry: Wirelessly Charged Self-Heating Coffee Mug

Many productive hackers bleed a dark ochre. The prevailing theory among a certain group of commenters is that they’re full of it, but it’s actually a healthy sign of a low blood content in the healthy hacker’s coffee stream. [Bharath] is among those who enjoy the caffeinated bean juice on a daily basis. However, he’d suffer from a terrible condition known as cold coffee. To combat this, he built an app-enabled, wirelessly chargeable, self-heating coffee mug.

We know that most hackers don’t start off planning to build objects with ridiculous feature lists, it just happens. Is there an alternate Murphy’s law for this? Any feature that can be added will? The project started off as some low ohm resistors attached to a rechargeable power bank. A insulated flask with a removable inner stainless steel lining was chosen. The resistors were fixed to the outside with a thermal epoxy.

However, how do we control the resistors? We don’t want to burn through our battery right away (which could end up more literally than one would like), so [Bharath] added a Linkit One microcontroller from Seeed Studio. With all this power at his disposal, it was natural to add Bluetooth, a temperature sensor, and app control to the cup.

After getting it all together, he realized that while the insides were perfectly isolated from the liquids held in the flask under normal use, the hole he’d have to cut to connect to the charging circuit would provide an unacceptable ingress point for water. To combat this he added the wireless charging functionality.

With his flask in hand, we’re sure the mood boost from not having to slog through the dregs of a cold container of coffee will produce a measureable improvement in productivity. Video after the break.

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14 thoughts on “Hackaday Prize Entry: Wirelessly Charged Self-Heating Coffee Mug

  1. If he had used a esp8266 to control everything he would of been able to goto its web page and not use a app. so he could use his pc instead of having to goto his phone only.

  2. Once again; make sure you don’t wake up tired, pour cold coffee into mug, and microwave! Hope you project works! Most of us can’t be motivated without at least one cup of Joe.

  3. I thought about making one of those a long time ago, out of one of those “thermos” mugs that plug into a car 12V source (i.e., the mechanical part is already done).

    Then I did the arithmetic. It’s useless without a battery as large as the mug itself. A typical large lipo or 18650 cell contains enough energy to heat the coffee just 5 degrees. (i.e., compensate for a 5 degree temperature loss).

    Just not worth the hassle. So I bought a good Zojirushi flask and moved on to other projects. With hot coffee.

  4. Maybe make a coffee machine that only brews the beverage a sip at a time. Powdering up the granules and feeding them into a cyclone like pipe with something akin to an injection moulding machine. Pass the pipe through an induction heater coil with the liquid temperature and flow rate controlling the frequency of the coil to regulate the temperature on the way to the user.

    1. Woo Hoo! 2.5 watts of heat available from USB2! Can heat a mug at the whopping rate of a tenth of a degree per minute! Six degrees per hour!

      A mug naturally cools off much faster than that: a USB heater will make an insignificant, probably unmeasureable, difference in the natural cooling rate of a freshly-decanted mugful.

      But people clearly buy this poorly-thought-out crap, so china continues to make it.

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