Decoding and Replicating Xantrex Solar Charge Wireless Data

This is a story mostly of decoding data, but there is a happy ending that includes turning that decoding work into an open source receiver. Xantrex solar charge controllers monitor a lot of data about what is happening with your solar panels, and they stream it wirelessly but you need their add-on hardware to receive it. [Eric Herbers] figured if the data is being transmitted, a resourceful hackers should be able to decode it. And he did just that with a little help from his friends in the Hackaday community.

We asked on Twitter what people were working on and [Eric] posted his scope screenshot. The conversation that followed helped point him in the right direction and others knowing about the project surely drove him to finish it. The decoding isn’t perfect, but achieve enough to decode and display voltage, amperage, and temperature. [Eric] built the display unit using an Arduino Pro Mini and a character LCD housed in you most common of black project boxes.

Door Bell Used To Reset WiFi Router

We’ve all have had to reset our routers or modems at some point because they were acting up. The typical scenario is; unplug the device, wait 30 seconds, plug it back in and wait for it to boot back up. While not hard, this can be an annoyance, especially if accessing the router or power cord is inconvenient. [Taylor] wrote in to tell us about his wireless router that seems to need to be reset more than he’d like. Although the simplest solution may be to get a new router, he thought it would be fun to do something a little more exciting by making a wireless reset controller.

[Taylor] started with an ordinary power strip. He spliced in a relay to the hot side of the AC line, connected to the common and normally-closed pins of the relay. That way, when the relay is not activated, the power strip is powered. Next, a wireless doorbell was re-purposed to act as the transmitter and receiver. The speaker was removed and the output lines connected to a mono-stable 555 timer circuit that [Taylor] made. When the circuit receives a signal from the door bell speaker lines, it will activate the relay for about 30 seconds. Since the relay was wired to supply voltage to the power strip when not activated, activating the relay cuts the power for 30 seconds effectively resetting the router. Now, whenever the router needs a reset, doing so is as easy as pushing the door bell button from anywhere in the house.

Raspberry Pi and Kindle Together Again

We’ve seen a lot of projects recently that take advantage of the Raspberry Pi 2’s augmented abilities. With the increased processor power and double the memory, it puts a lot more utility in the user’s hands. The latest project that takes advantage of this is the Pi-nk, which combines a Pi with a Kindle for some text-based awesomeness.

[Guillaume] has put together this detailed how-to which, unlike other builds we’ve seen in the past, uses wireless instead of USB for almost all of the connections, including the keyboard. Granted, this isn’t a new idea, but he’s presenting the way that he did it. To that end, all of the commands you’ll need to use are extremely well documented on the project page if you want to build your own. When everything is said and done, you’ll be SSHing into the Pi from the Kindle and using the popular “screen” program to get the Pi to use the Kindle as its display.

Additionally, [Guillaume] has posted some schematics for custom enclosures for the Pi-Kindle pair if you’re more ambitious. He points out that the e-ink display is great if the Pi is being run in text or command-line mode, and we’d have to agree. This is a very clean pairing of these devices and puts the strengths of both to great use!

Ask Hackaday: Is Amazon Echo the Future of Home Automation?

Unless you’ve been living under a case of 1 farad capacitors, you’ve heard of the Amazon Echo. Roughly the size of two cans of beans, the Echo packs quite a punch for such a small package. It’s powered by a Texas Instrument DM3725 processor riding on 256 megs of RAM and 4 gigs of SanDisk iNAND ultra flash memory. Qualcomm Atheros takes care of the WiFi and Bluetooth, and various TI chips take care of the audio codecs and amplifiers.

What’s unique about Echo is its amazing voice recognition. While the “brains” of the Echo exist somewhere on the Internets, the hardware for this circuitry is straight forward. Seven, yes seven microphones are positioned around the top of the device. They feed into four Texas Instrument 92dB SNR low-power stereo ADCs. The hardware and software make for a very capable voice recognition that works from anywhere in the room. For the output sound, two speakers are utilized – a woofer and a tweeter. They’re both powered via a TI 15 watts class D amplifier. Check out this full tear down for more details of the hardware.

circuit board

Now that we have a good idea of the hardware, we have to accept the bad news that this is a closed source device. While we’ve seen other hacks where people poll the to-do list through the unofficial API, it still leaves a lot to be desired. For instance, the wake word, or the word which signals the Echo to start listening to commands, is either “Alexa” or “Amazon”. There is no other way to change this, even though it should be easily doable in the software. It should be obvious that people will want to call it “Computer” or “Jarvis”. But do not fret my hacker friends, for I have good news!

It appears that Amazon sees (or had seen all along) that home automation is the future of the Echo. They now officially support Philips Hue and Belkin WeMo gadgets. The Belkin WeMo, which is no stranger to the hacker’s workbench, has a good handle on home automation already, making the ability to control things in your house with the Echo tantalizingly close. See the video below where I test it out. Now, if you’re not excited yet, you haven’t heard of the WeMo Maker, a device which they claim will let you “Control nearly any low-voltage electronics device“. While the WeMo Maker is not supported as of yet, it surely will be in the near future.

We know it sucks that all of this is closed source. But it sure is cool! So here’s the question: Is the Echo the future of home automation? Sure, it has its obvious flaws, and one would think home automation is not exactly Amazon’s most direct business model (they just want you to buy stuff). However, it works very well as a home automation core. Possibility better than anything out there right now – both closed and open source.

Do you think Amazon would ever open the door to letting the Echo run open source modules which allow the community to add control of just about any wireless devices? Do you think that doing so would crown Amazon the king of home automation in the years to come?

Continue reading “Ask Hackaday: Is Amazon Echo the Future of Home Automation?”

Reverse-Engineering a Wireless BBQ Thermometer

[Bob] has his own smoker and loves to barbecue, but doesn’t like spending all day checking on his smoker’s temperature. He thought about building his own wireless thermometer setup, which would have been pretty awesome, but then he had a better idea: why not hack an existing wireless barbecue thermometer? [Bob] purchased an off-the-shelf wireless BBQ thermometer and reverse-engineered its wireless protocol to make his own wireless thermometer setup.

The first problem [Bob] encountered was figuring out the frequency of the transmitter. Thankfully [Bob] had access to a spectrum analyzer, where he discovered the transmitter was running at 433.92MHz (a cheap RTL-SDR dongle would also get the job done). Next, [Bob] started digging into the manufacturer’s FCC filings and found that it actually called out the transmit frequency, which matched the transmit frequency he measured. He also found a ton of other helpful information in the filing, like a block diagram and full transmitter schematic.

[Bob] used a Radiometrix RF module to receive the thermometer’s signal. He hooked up the output to his logic analyzer to start decoding the protocol. After a quick visual analysis, [Bob] found that the signal was a preamble followed 13 bytes of Manchester-encoded data being transmitted at 2kbps. He started collecting data with known temperatures, created a table of the data, and began looking for patterns. After quite a bit of searching [Bob] was successfully able to find and parse the temperature values out of the data stream. [Bob] did a great job of documenting his process and results, so check out his writeup if you want to try it out yourself.

Internet Knows Your Every Move Thanks to IKEA and ESP8266

[terenceang] got his feet wet with the ESP8266 WiFi module by hacking up an IKEA Molgan PIR light. The stock PIR light simply lights when motion is detected. [terenceang] added some extra functionality to it by making it send notifications to his phone as well.

The default configuration of the stock PIR light was to only work at night. This is done with a photo diode. It was removed to make it work in daylight, along with several other components. He removed a handful of current limiting resistors to disable the hi output LEDs. One was preserved as a visual indicator. The onboard voltage regulator didn’t supply enough current for the ESP8266. [terenceang] used some electronic wizardry and was able to solve the problem with an opto-coupler.

The one thing he would change is moving from battery to mains power, as expected battery life is less than two weeks.Schematics, source code and tons of great pictures are available on his blog. If you want to give it a try but need a crash course check out the recent news that the Arduino IDE works with ESP8266, or give direct programming a try.

Reverse Engineering Wireless Temperature Probes

[bhunting] lives right up against the Rockies, and for a while he’s wanted to measure the temperature variations against the inside of his house against the temperature swings outside. The sensible way to do this would be to put a few wireless temperature-logging probes around the house, and log all that data with a computer. A temperature sensor, microcontroller, wireless module, battery, case, and miscellaneous parts meant each node in the sensor grid would cost about $10. The other day, [bhunting] came across the exact same thing in the clearance bin of Walmart – $10 for a wireless temperature sensor, and the only thing he would have to do is reverse engineer the protocol.

These wireless temperature sensors are exactly what you would expect for a cheap piece of Chinese electronics found in the clearance bin at Walmart. There’s a small radio operating at 433MHz, a temperature sensor, and a microcontroller under a blob of epoxy. The microcontroller and transmitter board in the temperature sensor were only attached by a ribbon cable, and each of the lines were labeled. After finding power and ground, [bhunting] took a scope to the wires that provided the data to the radio and took a look at it with a logic analyzer.

After a bit of work, [bhunting] was able to figure out how the temperature sensor sent data back to the base station, and with a bit of surgery to one of these base stations, he had a way to read the temperature data with an Arduino. From there, it’s just a data logging problem that’s easily solved with Excel, and [bhunting] has exactly what he originally wanted, thanks to a find in the Walmart clearance bin.