Sous Vide cooking with an Arduino Uno

Sous-vide (/suːˈviːd/; French for “under vacuum”) is a method of cooking food sealed in airtight plastic bags in a water bath for an extended period of time (up to 72 hours). The intention? To cook food evenly, leaving the dish juicier and more flavorful. 

The theory – first described by Sir Benjamin Thompson (Count Rumford) in 1799 – was re-discovered by American and French engineers in the mid-1960s.

According to Wikipedia, the method was subsequently adopted by Georges Pralus in 1974 for the Restaurant Troisgros (of Pierre and Michel Troisgros) in Roanne, France. The sous-vide method has since been used in numerous high-end gourmet restaurants by chefs, while gradually moving into the realm of home cooking.

Recently, an inexpensive, yet effective Arduino-powered Sous Vide cooker surfaced on Instructables.

 Designed by Etienne Giust, the Sous Vide cooker is built around a standard rice cooker, an Atmel-based Arduino Uno (ATmega328) and a sketch (software) that adapts itself to the particular characteristics of a specific cooker.

Additional key components include:

• Integrated 8 digits led display with MAX7219 control module (3 wire interface) – 5$
• Pushbutton x 2
• Piezo buzzer – 3$ (optional)
• Waterproof DS18B20 Digital temperature sensor – 10$
• 4.7K ohm resistor
• 5V Relay module for Arduino, capable of driving AC125/250V at 10A – 4$
• A wood board, plastic box and silicone sealant

Total cost? $40, not including the rice cooker.

“Use the two pushbuttons to set the target temperature (acceptable temperatures are within the 50°C to 90°C range). The actual temperature can be monitored on the LED display,” Giust explained in his Instructables post.

“It is advisable not to open the lid during the initial heating phase, where the characteristics of the rice cooker are monitored. When the buzzer sounds, you can open the lid and put your bagged food in the water. If you connect the Arduino to your PC, data is sent to the serial port. Once stripped, this data can be used to plot the temperature over time.”

Interested in learning more? You can check out the project’s official Instructables page here.

Cooking with Atmel MCUs

Did you know that some scientists believe the advent of cooking played an important role in human evolution? Indeed, most anthropologists theorize that cooking fires first developed around 250,000 years ago, with the rise of agriculture, commerce and transportation between civilizations in different regions offering cooks many new ingredients.

Clearly, we’ve come a long way since the days when humans roasted meat on a spit over an open fire without any utensils, appliances or kitchens to be seen. Today, however, cooking appliances such as stoves, microwave ovens and conventional ovens typically require a combination of temperature and mass sensors, programmable timers and sophisticated motor control for relevant components. A number of current-gen units include remote controls, as well as rich, responsive touch control interfaces which are key for ease of use.

Now we’ve discussed quite a number of use cases for Atmel MCUs over the past few days, including automotive, lighting, telecare and even washing machines. So it shouldn’t come as much surprise to readers of Bits & Pieces that Atmel also offers a lineup of touch solutions and customizable microcontrollers which are ideal to power a wide range of cooking appliances.

Indeed, AVR microcontrollers are available in 105°C versions, as well as models up to 150°C, which are perfect for high temperature cooking requirements. Plus, Atmel offers a wide range of 8- and 32-bit microcontrollers dedicated to motor control – providing support for BLDC motors, AC motors and switched reluctance motors.

AVR 32-bit microcontrollers also feature a multi-layer databus and DMA controller that make them a perfect fit for HMI applications where high bandwidth is required. Meanwhile, robust touch sensor technology, coupled with Atmel’s QTouch library, allows designers to add capacitive touch buttons, sliders and wheels – without additional cost.

In addition, native 5 volts support is available on the Atmel megaAVR and Atmel tinyAVR microcontrollers (MCUs), with high integration solutions, such as motor control and HMI touch in a single-chip, helping to reduce BOM. ZigBee PRO compatibility enables standards-compliant connectivity and smart metering, with node authentication capability supports smart meter infrastructure connections.

And last, but certainly not least, Atmel’s QMatrix technology offers a robust method to implement buttons and sliders in capacitive touch-technology, while built-in support for water rejection makes the QTouch solutions ideal for demanding environments.

Interested in learning more? Additional information about Atmel MCUs targeting various cooking appliances can be found here.