Improving Rice Cooker Efficiency

Looking at the plate on the bottom of his electric rice cooker, [AC_Hacker] was surprised to find that it was rated to consume 400 watts. Furthermore when he measured its consumption he found that it consumed 385 watts without even having a cooking cycle initiated. The circuit to keep cooked rice warm was always on – even when the cooking circuit wasn’t engaged.

Something clearly had to be done, so he set about modifying the cooker for better economy. Removing the base revealed that disabling the warming circuit was as simple as disconnecting it. [AC_Hacker] also noticed that the device had no thermal insulation. There was plenty of space between the inner and outer walls, so he packed it with glass wool. The final modification was to reduce the power taken by the heater by installing a half-wave rectifier diode. The cooker still reached the desired temperature, it just used half the power.

You might think that would be the end of it, given that the modifications significantly reduced the cooker’s power consumption without detriment to its rice cooking ability. Rice now took a little longer to cook, so there was still room for improvement. The moment of inspiration came when [AC_Hacker] realized that the cooking time was proportional to the amount of water used in a cooking cycle. He could safely reduce the water without affecting the cooked rice. A 30% water reduction led to a proportional cooking time reduction, and rice cooked using a lot less power.

Surprisingly this seems to have been Hackaday’s first rice cooker hack. Perhaps that’s because you’ve been so busy supplying us with sous vide hacks to write about.

Endless Pancakes

Sometimes along comes a machine so simple yet so alluring in what it does and how it achieves its aim that you just want one. Doesn’t matter what it does or indeed whether ownership is a practical proposition, you wish you could have one in your possession.

What machine could trigger this reaction, you ask? [Robbie Van Der Walt] and [Christiaan Harmse] have the answer, their machine performs the simple but important task of cooking an endless pancake. A hopper dispenses a layer of pancake batter onto a slowly rotating heated roller that cooks the ribbon of pancake on one side, before it is transferred to another roller that cooks the other side. It seems simple enough yet the simplicity must hide a huge amount of product refinement and probably many miles of lost pancake. Pancakes it seems are a traditional South African delicacy, evidently they must have king-sized appetites to satisfy.

In the video below (Afrikaans, English subtitles) they make an attempt at a world record for the longest ever pancake, though sadly they don’t seem to appear in a Guinness  World Records search so perhaps they didn’t achieve it. Still, their machine is a work of art, and we applaud it. Continue reading “Endless Pancakes”

Edible art from a Robot Pancake Printer

In case you didn’t know it, pancake art is a thing. People are turning out incredible edible artwork using squeeze bottles and pancake batter. But even if you’re not terribly artistic, you can still amaze your breakfast buddies with this robotic pancake printer.

At its simplest – and in our opinion its most impressive – pancake art involves making patterns with thin batter on a hot griddle. The longer the batter is cooked, the darker it becomes, and art happens. To capitalize on this, [Trent], [Kevin], [Sunny] and [Isaac] built a 2-axis gantry with a working area the size of an electric griddle. A bottle is pressurized with a small air pump and controlled by a solenoid valve to serve as a batter extruder, and an Arduino controls everything. Custom pancake design software lets you plan your next masterpiece before committing it to batter.

Sadly, the video below shows us that the team didn’t include an automatic flipper for the pancake, but no matter – that’ll make a great feature for the next version. Maybe something like this?

Continue reading “Edible art from a Robot Pancake Printer”

Bluetooth Thermometer Minds Your Meats

The summer may have come to a close here in the USA, but any time of the year is a good time for grilling. In the colder weather, it’s a drag to have to stay near the hot grill to keep an eye on your burgers and franks. [Eric Ely] thought it would be smarter to have a meat thermometer that sent his phone the current reading via Bluetooth.

Instead of starting from scratch, [Eric] took an off the shelf electronic thermometer and removed its temperature probe (which was a thermistor). The hardware used an off the shelf Bluetooth board with a companion battery board and prototype board. If you can’t bear to cut up a good thermometer, you can get replacement probes that ought to work just as well.

In addition to the boards and the scavenged thermistor, [Eric] used a couple of resistors. One resistor is in parallel with the thermistor to improve the linearity of the device’s response curve. The second resistor forms a voltage divider that the Bluetooth board reads.

The software (using Node.js and C) is available on Github. The C program reads the temperature and pushes it out using JSON. Node.js provides a server that [Eric] can hit with his phone’s Web browser.

Sure, you can buy wireless thermometers, but what self-respecting hacker wants to carry around a store-bought box just to display meat temperature? Viewing it on your phone has much more street cred.  Of course, a real hacker isn’t going to cook on a conventional grill, either.

Continue reading “Bluetooth Thermometer Minds Your Meats”

Arduino-Based Dispenser Delivers Liquids, Powders

If you like to cook or bake, you probably don’t measure everything out in little bowls and ramekins before you start. Well,unless you also happen to like doing dishes. Even so, there are a lot of measuring spoons and -cups that end up getting dirty in the process. But what if you had a measuring machine to dole out spices and low-viscosity liquids in specific quantities for you?

[enddev]’s creation is based around an Arduino Mega, and the interface is three buttons and an LCD. The user selects between liquid and powder, followed by the desired measurement. If liquid is chosen, the peristaltic pump is engaged to deliver the specified amount through silicone tubing. The current powder setup uses a kitchen scale, which the designers found to be inaccurate for small amounts. They believe that a volume auger and stepper motor would be ideal.

The team mentions that the powder delivery system is better suited for flakier substances since it’s basically agitated out of the container. This makes us think this would be great for feeding fish. If you take this admirably-written Instructable and use it to feed your fish or something, let us know. Their code is on the gits.

[via Embedded Lab]

Precision Temperatures for Cooking or Whatever

sous-vide temp controller

If you have not heard of the sous-vide method of cooking you are not alone. This method uses a low temperature water bath to cook food in airtight plastic bags. Because the temperatures are much lower than normal the cooking time must be much longer and the actual temperature is very critical. The advantage is that the food is heated evenly without overcooking the outside. Since the food is bagged, it also retains moisture.

[Brian] put together a sous-vide control system to automatically maintain the correct temperature of a rice cooker. A temperature control unit was sourced on eBay for about $15. This is not a bad deal considering it has an LED display, control buttons, built-in relay and thermometer input. The control unit is mounted inside a project box with a few other components. The 120 volt AC line comes into the box where the neutral and ground are connected to the control unit and a standard outlet. The hot wire is connected directly to the control unit which determines if the hot wire is or isn’t connected to the outlet by using its built-in relay.

Continue reading “Precision Temperatures for Cooking or Whatever”

Repairing and Adding Bluetooth Control to an Induction Cooker

When his 6 years old induction cooker recently broke, [Johannes] decided to open it in an attempt to give it another life. Not only did he succeed, but he also added Bluetooth connectivity to the cooker. The repair part was actually pretty straight forward, as in most cases the IGBTs and rectifiers are the first components to break due to stress imposed on them. Following advice from a Swedish forum, [Johannes] just had to measure the resistance of these components to discover that the broken ones were behaving like open circuits.

He then started to reverse engineer the boards present in the cooker, more particularly the link between the ‘keyboards’ and the main microcontroller (an ATMEGA32L) in charge of commanding the power boards. With a Bus Pirate, [Johannes] had a look at the UART protocol that was used but it seems it was a bit too complex. He then opted for an IOIO and a few transistors to emulate key presses, allowing him to use his phone to control the cooker (via USB or BT). While he was at it, he even added a temperature sensor.