Although the Internet of Things (IoT) is a reasonably new term, the idea isn’t really all that new. Many engineers and hackers have created networked embedded systems for many years. So what’s different? Two things: the Internet is everywhere and the use of connected embedded systems in a consumer setting.
Like anything else, there’s a spectrum of usefulness to IoT. Watching The Expanse, the other day (which is not a bad show, by the way), I noticed that if you had the right IoT lights, you could run an app that would change your lighting to suit the show in real-time. I don’t have those lights, but I suppose when the action moves to a dark sub-basement, your lights dim and when you are in a space ship’s reactor room, they turn red, and so on. Fun, but hardly useful or life-changing.
On the other hand, there are some very practical IoT items like the Nest thermostat. It might seem lazy to want to monitor and control your thermostat from your tablet, but if you are frequently away from home, or you have multiple houses, it can be a real positive to be able to control things remotely. With the recent blizzard on the U.S. east coast, for example, it would be great to turn on the heat in your weekend cottage 150 miles away while you were still at work or home. However, the Nest recently had a hiccup during an upgrade and it has made many of their customers mad (and cold). I’ll get back to that, in a minute. First, I want to talk about the problems with deploying something that will be in many varied environments (like people’s homes) that controls something real.
[Sven337] was gifted a steam cleaner, and seemed pretty happy because it helped clean the floor better than a regular mop. Until it fell one day, and promptly stopped working. It would produce steam for a short while and then start spitting out cold water, flooding the floor.
Like any self-respecting hacker, he rolled up his sleeves and set about trying to fix it. The most-likely suspect looked like the thermostat — it would switch off and then wouldn’t switch on again until the water temperature fell way below the target, letting out liquid water instead of steam after the first switching cycle. A replacement thermostat was ordered out via eBay.
Meanwhile, he decided to try out his hypothesis by shorting out the thermostat contacts. That’s when things went south. The heater worked, and got over-heated due to the missing thermostat. The over-temperature fuse in the heater coil blew, so [Sven337] avoided burning down his house. But now, he had to replace the fuse as well as the thermostat.
[Sven337] bundled up all the parts and put them in cold storage. The thermostat arrived after almost 2 months. When it was time to put it all together, a piece of fibreglass tubing that slides over the heater coil was missing. Without the protective sleeve, the heater coil was shorting out with the grounded heater body, blowing out the fuses in his apartment.
That’s when [Sven337] called it a day and threw out the darn steam mop — a few dollars down the drain, a few hours lost, but at least he learnt a few things. Murphy’s Law being what it is, he found the missing insulation sleeve right after he’d thrown it away.
If you’ve ever lived in a building with manually controlled central heating, you’ll probably understand [Martin]’s motivation for this hack. These heating systems often have old fashioned valves to control the radiator. No Nest support, no thermostat, just a knob you turn.
To solve this problem, [Martin] built a Wi-Fi enabled thermostat. This impressive build brings together a custom PCB based on the ESP8266 Wi-Fi microcontroller and a mobile-friendly web UI based on the Open Thermostat Scheduler. The project’s web server is fully self-contained on the ESP8266.
To replace that manual value, [Martin] used a thermoelectric actuator from a Swiss company called HERZ. This is driven by a relay, which is controlled by the ESP8266 microcontroller. Based on the schedule and the measured temperature, the actuator lets fluid flow through the radiator and heat the room.
As a bonus, the device supports NTP for getting the time, MQTT for publishing real-time data, and ThingSpeak for logging and graphing historic data. The source code and design files are available under a Creative Commons license.
When [William’s] thermostat died, he wanted an upgrade. He found a few off-the-shelf Internet enabled thermostats, but they were all very expensive. He knew he could build his own for a fraction of the cost.
The primary unit synchronizes it’s time using NTP. This automatically keeps things up to date and in sync with daylight savings time. There is also a backup real-time clock chip in case the Internet connection is lost. The unit can be controlled via the physical control panel, or via a web interface. The system includes a nifty “vacation mode” that will set the temperature to a cool 60 degrees Fahrenheit while you are away. It will then automatically adjust the temperature to something more comfortable before you return home.
[William’s] home is split into three heat zones. Each zone has its own control panel including an LCD display and simple controls. The zones can be individually configured from either their own control panel or from the central panel. The panels include a DHT22 temperature and humidity sensor, an LCD display, a keypad, and support electronics. This project was clearly well thought out, and includes a host of other small features to make it easy to use.
Ever since [The Nooganeer] bought his first home with his wife back in the spring of 2014, he’s had ever consuming dream of adding home automation to every appliance. As he puts it…
Home automation has always been a fascination of mine. How much time and irritation would I save if I didn’t have to worry about turning things on and off, or wonder in which state they were left? How much more efficient would my home be? Wouldn’t it be cool to always know the state of every power consumer in my home, and then be able to record and analyze that data as well?
His first challenge was making a smart thermostat — after all, heating and cooling your house typically takes the most energy. Having used a Raspberry Pi before he figured it would be the best brain for his system. After researching a bit about HVAC wiring, [The Nooganeer] settled on a Makeatronics Solid State Relay board to control the HVAC. This allows him to use the GPIO’s on the Raspberry Pi in order to control the furnace and AC unit. Continue reading “Raspberry PiPhone Thermostat Monitors Your Entire House — Or At Least That’s The Plan”→
There’s a new piece of electronics from China on the market now: the USR-HTW Wireless Temperature and Humidity Sensor. The device connects over Wi-Fi and serves up a webpage where the user can view various climate statistics. [Tristan] obtained one of these devices and cracked open the data stream, revealing that this sensor is easily manipulated to do his bidding.
Once the device is connected, it sends an 11-byte data stream a few times a minute on port 8899 which can be easily intercepted. [Tristan] likes the device due to the relative ease at which he could decode information, and his project log is very detailed about how he went about doing this. He notes that the antenna could easily be replaced as well, just in case the device needs increased range.
There are many great reasons a device like this would be useful, such as using it as a remote sensor (or in an array of sensors) for a homemade thermostat, or a greenhouse, or in any number of other applications. The sky’s the limit!
Thermostats can be a pain. They often only look at one sensor in a multi-room home and then set the temperature based on that. The result is one room that’s comfortable and other rooms that are not. Plus, you generally have to get up off the couch to change the temperature. In this day and age, who wants to do that? You could buy an off-the-shelf solution, but sometimes hacking up your own custom hardware is just so much more fun.
[redditseph] did exactly that by modifying his home thermostat to be controlled by a Raspberry Pi. The temperature is controlled by a simple web interface that runs on the Pi. This way, [redditseph] can change the temperature from any room in his home using a computer or smart phone. He also built multi-sensor functionality into his design. This means that the Pi can take readings from multiple rooms in the home and use this data to make more intelligent decisions about how to change the temperature.
The Pi needed a way to actually talk to the thermostat. [redditseph] made this work with a relay module. The Pi flips one side of the relays, which then in turn switches the buttons that came built into the thermostat. The Pi is basically just emulating a human pressing buttons. His thermostat had terminal blocks inside, so [redditseph] didn’t have to risk damaging it by soldering anything to it. The end result is a functional design that has a sort of cyberpunk look to it.