Nest Thermostat Inspires DIY, Open-Source Versions

Nest Labs, the creators of network-connected home devices such as the Nest Thermostat and the Nest Protect smoke detector, generated a lot of buzz in January when Google announced that they were acquiring the company for $3.2 billion in cash. The news inspired the folks at Spark Labs to use their Spark Core Wifi-enabled microcontroller to build their own version of the Nest Thermostat.

“At Spark, we’re making it easier to bring connected devices to market with the Spark Core, our Wi-Fi development kit, and the Spark Cloud, our cloud service for connected devices,” according to the project’s introduction. “And to prove it, we built our own approximation of the Nest Learning Thermostat in one day — and we’ve open sourced everything.”

Their project uses the Spark Core for the brains, three I²C LED matrices for display, an I²C temperature and humidity sensor, and a PIR motion sensor to tell if you’re home or not. They don’t have all the functionality of a Nest Thermostat, but they remind their readers that “every polished product starts as a rough prototype.”

They enclosed the project into an acrylic and wood assembly, digitally fabricated using a laser cutter and CNC mill, respectively. After uploading their firmware code and creating a web-based backend with a REST API, they had their own network-connected learning thermostat. “The beauty of a connected device is that it can be constantly improving, whether it’s by updating the firmware, updating the cloud software, or by using machine learning to optimize and improve the logic of the device.”

The team of 3.5 engineers spent one long day and about $70 on components to design and build the project. This includes $39 for the Spark Core but excludes the wood and acrylic, which they got for free. All of the code and design files are available on Github if you want to make your own smart thermostat inspired by Nest.

Adafruit is also toying with plans to create their own open source smart thermostat. They put a feeler out on their blog and Google+ page recently along with a rendering from Mike Doell, who is helping to design the project. Their thermostat will be based around the popular Raspberry Pi single board computer. The posts generated a flood of positive feedback from their customers. “The response for an ‘open source Nest’ has been fantastic,” said Limor Fried, founder and engineer of Adafruit Industries. “We put out the general question ‘should we make this’ and the answer appears to be a very passionate YES!”

They’re currently speccing out a kit, complete with code and tutorials—in typical Adafruit fashion. Their hope is that the price of the kit will stay under the $100 threshold. According to Limor, features of the project are likely to include data logging, actions based on temperature and your calendar, self programming over time, and remote access.

And Adafruit isn’t stopping at smart thermostats, either. They’ve seen a lot of excitement around their CC3000 breakout board, which makes it much easier for a project to connect to the Internet via Wifi. In their learning system, you can find plenty of example projects that use the board, from Wifi weather stations to wireless gardening. It’s all part of a growing interest around DIY internet of things and connected home projects.

However, it’s not just easy connectivity that’s driving this change. It’s likely that much of this interest stems from a concern over privacy of personal data. Limor herself weighed in on the issue in a recent New York Times opinion article where she proposes a bill of rights for companies making connected devices.

“We think our Internet of Things Bill of Rights is the direction makers and just about anyone who cares about their data wants to see for the most intimate place, their homes,” said Limor.

Whatever the motivation is to create DIY connected home devices, there’s little doubt that we’ll be seeing a lot more projects like these in the future. The tools are becoming more accessible, more powerful, and less expensive. Resources and documentation are becoming more thorough. All along, the desire to take control of the home has been a common endeavor for makers everywhere. And more than ever, there’s no lack of inspirational work like these projects to keep us motivated to push the available technology to its limits.