Google’s pending $3.2 billion acquisition of Nest Labs brings it a hot selling, Linux-based smart thermostat — and a launchpad for the Internet of Things.

Google’s stock price rose 1 percent the day after it announced it planned to acquire Nest Labs for $3.2 billion. The acquisition topped off a CES show in Las Vegas that was awash in similar, low-cost, smartphone-accessible home automation devices. Like most of these products, including Belkin’s WeMo and Ivee’s new Ivee Sleek, Nest Lab’s Learning Thermostat runs on embedded Linux. The Nest Protect Smoke + CO Alarm lists the open source FreeBSD, NetBSD, and FreeRTOS. (See farther below for more details on the products.)

The cash deal is Google’s second-largest after its $12.5 billion acquisition of Motorola Mobility. Pending regulatory approval, the acquisition should close in a few months, said Google.

Palo Alto-based Nest Labs, which has more than 300 employees, will continue as a subsidiary under the leadership of CEO Tony Fadell, and the branding will remain the same, according to Google. The Nest co-founder was one of the key developers of Apple’s iPod, and the other co-founder, Matt Rogers, was one of the key developers of the original iPhone, and also worked on the iPad.

Unlike most of its Linux-based rivals in the fledgling smart home automation category, the company was funded not by Kickstarter, but by big-time VCs like Kleiner Perkins, Lightspeed Venture Partners, and Shasta Ventures. Google Ventures has a share, as well.

With Google’s acquisition, Nest should be able to more quickly expand outside of its current North American market. In a statement, Google CEO Larry Page hinted as much when he said the search giant was “excited to bring great experiences to more homes in more countries.” Nest Labs is already in the process of launching sales in the U.K.

The acquisition should also help Nest expand its product line. While most home automation ecosystems start out with smart lighting, thermostats, locks, and smart appliances, Nest so far has played it conservative by focusing on just two products: the thermostat and smoke alarm. However, it has also forged key partnerships with leading energy companies, and claims to have more than 25,000 certified professionals who install its devices throughout North America. A year ago, it reported shipping 40,000 to 50,000 thermostats each month, according to Business Insider. Google’s investment should expand that sturdy base into a larger ecosystem, as well as other new wireless-enabled Internet of Things (IoT) devices.

Nest Thermostat apps (click to enlarge)

The new wave of low-cost home automation devices has been enabled by ubiquitous mobile device usage, web APIs, and cloud software, in addition to the lowering costs of sensors and embedded processors. Like almost all the other products in this category, Nest lets you remotely monitor and adjust the devices via Android and iOS apps. In an interview at The Verge, Fadell was quoted as saying there were no plans to shut out Apple and make the devices accessible only from Android devices.

It remains to be seen whether Nest will switch its embedded Linux OS to Android. Presumably, the company would do that only when and if it starts offering devices with touchscreen interfaces, or when Android evolves to match embedded Linux in its embedded and IoT proficiency. Since Nest already mixes Linux and FreeBSD in the same ecosystem, there’s no reason why Android couldn’t play a role there as well.

 
Nest Learning Thermostat

According to Nest, most thermostats waste enormous amounts of energy, or around $173 a year. Nest’s flagship Nest Learning Thermostat is claimed to reduce energy costs by an average of 19.5 percent.

Nest Learning Thermostat
(click images to enlarge)

The thermostat exhibits the founders’ Apple-forged sense of consumer design. The round, brushed-metal device features a convex glass screen that protects a similarly round LCD display. The sides of the device reflect the color of the surrounding wall in order to better blend in. The 1.75-inch, 320 x 320-pixel display offers 24-bit color.

Nest Thermostat electronics (click to enlarge; source: sparkfun.com)

Nest has posted some specs, but has nothing on the processor or memory. Its open source code page suggests a Texas Instruments (TI) OMAP processor, however, and when the product first shipped in 2011, a year after the company was founded, a SparkFun teardown showed images of TI’s Cortex-A8-based Sitara AM3703 processor, which lacks the 3D graphics of its AM3715 sibling. (Image source: Sparkfun.com.)

According to Nest, the Nest Learning Thermostat is further equipped with 802.11b/g/n (WiFi) and 802.15.4 (ZigBee) radios, both tuned to 2.4GHz, thereby offering a wider range of smart devices it can interact with. Sensors include temperature, humidity, and ambient light, as well as “far-field” and “near-field” activity sensors. The thermostat can compensate for changes in heat caused by direct sunlight.

The 3.3 x 1.3-inch (83 x 32mm) device runs on less than 0.03kWh per month, and has a rechargeable Li-Ion battery, says Nest Labs. It can withstand operating temperatures of 0 to 40°C, and works with 95 percent of 24V heating and cooling systems, says the company. Up to 10 Nest devices can be controlled by one Nest account, with multi-zone support, and you can even control two homes simultaneously.

The firmware, which is revealed onscreen and via the mobile apps, can perform functions such as automatically adjusting the temperature when you’ve left the house, and offering guidance for optimal energy efficiency. It can do things like turn off the air conditioner while keeping the fan going, in order to save energy, or remind you to change heating and AC filters. It’s said to be optimized for a wide variety of heat sources, including heat pumps.

Users enjoy extensive customization of heating and cooling systems, and can set up a weekly schedule. However, you can also change settings on the fly. As the product name suggests, the system also adjusts its settings based on your activity patterns.

 
Nest Protect Smoke + CO Alarm

Nest Labs developed the Nest Protect device because it realized most people hate their smoke and carbon monoxide alarms. Like the thermostat, the device can be controlled from the mobile app, and it responds to minor smoke events such as burning toast with lighting indicators and a human voice. It won’t set off the full alarm unless the event continues or worsens, and you can hush the alarm with a simple wave. The voice alarm will inform you where the event is happening. If the batteries are getting low, it will emit a light signal instead of chirping.

Nest Protect Smoke + CO Alarm
(click images to enlarge)

It’s unclear what processor or microcontroller sits within the Nest Protect Smoke + CO Alarm, but it appears to run on a combination of open source operating systems, including FreeBSD, NetBSD, and FreeRTOS. Indeed, it’s a simpler device than the thermostat, without a screen, but it has the same WiFi and ZigBee radios, as well as a speaker, horn, and voice alarms for smoke and carbon monoxide. The sensors are dedicated to the task, and include photoelectric smoke, carbon monoxide, heat, humidity, ambient light, and three activity sensors.

The 5.3 x 5.3 x 1.6-inch Nest Protect is available in a battery-driven model that takes six AA Energizer Ultimate Lithium batteries, and a wired version with a 120V AC connector and three of the AA batteries for backup. The device can work independently collaborate with the Nest Learning Thermostat. For example, in the event of a carbon monoxide alarm, the thermostat will turn off the furnace.

The Nest Learning Thermostat and Nest Protect are available for $249 and $129, respectively. More information may be found on the Nest Learning Thermostat product page and the Nest Protect product pages.