Forget Wifi or Bluetooth, Pair Directly With Your Phone’s Speaker

[Kedar Nimbalkar] hyperbolically advertises the ultimate cell phone speaker dock. It costs a dollar. It doesn’t need you to pair with it via Bluetooth or WiFi. It pairs extremely fast, 0.000000000001, he clarifies. It may also look like a broken laptop speaker with a stomped wall wart soldered to it, but who can keep up with industrial design trends these days?

He shows us the device in operation. He starts playing some music on his phone’s speaker. It’s not very loud, so he simply lays the phone on the dock. Suddenly, all the audio fidelity a Dell Lattitude from the 90s can provide erupts from the device! How is this done?

Of course, there’s not much to the trick. Since the cellphone speaker is a coil it can induce a small current in another coil. The resulting voltage can be picked up by an audio amplifier and played through the speakers. Nonetheless it’s pretty cool, and we like his suggestion of betting our friends that we could wirelessly pair with their ear buds. Video after the break.

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Converting a TP Link Router to Mission Control for Cheap 433MHz Home Automation

[Jean-Christophe Rona] found himself with some free time and decided to finish a project he started two years ago, reverse engineering cheap 433MHz home automation equipment. He hopes to control his space heaters remotely, in preparation for a cold and, now, robotic winter.

In a previous life, he had reverse engineered the protocol these cheap wireless plugs, garage doors, and electric window shutters all use. This eventually resulted in a little library called rf-ctrl that can toggle and read GPIO pins in the correct way to control these objects. He has a few of the more popular protocols built into the library and even wrote a guide on how to do the reverse engineering yourself if you have need.

Having successfully interfaced with the plugs to use with his space heaters, [Jean-Christophe] went about converting a cheap TP Link router into a command center for them. Since TP Link never expected anyone to hammer their square peg into a mismatched hole, it takes a careful hand at soldering and some enamel wire to break out the GPIO pins, but it’s well within the average skill set.

The end result is a nicely contained blue box with a little antenna hanging out of it, and we hope, a warm abode for the coming winter.

Internet Doorbell Gone Full-Hipster

There are things and there are Things. Hooking up an Internet-connected doorbell that “rings” a piezo buzzer or sends a text message is OK, but it’s not classy. In all of the Internet-of-Things hubbub, too much attention is paid to the “Internet”, which is actually the easy part, and too little attention is paid to the “Things”.

[Moris Metz] is a hacker in Berlin who has a bi-weekly national radio spot. (Only in Germany!) This week, he connected the ubiquitous ESP8266 to a nice old (physical) bell for his broadcast over the weekend. (i”Translated” here.) Check out the video teaser embedded below.

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WarWalking With The ESP8266

[Steve] needed a tool to diagnose and fix his friend’s and family’s WiFi. A laptop would do, but WiFi modules and tiny OLED displays are cheap now. His solution was to build a War Walker, a tiny handheld device that would listen in WiFi access points, return the signal strength, and monitor the 2.4GHz environment around him.

The War Walker didn’t appear out of a vacuum. It’s based on the WarCollar Dope Scope, a tiny, portable device consisting of an off-the-shelf Chinese OLED display, an ESP8266 module, and a PCB that can charge batteries, provide a serial port, and ties the whole thing together with jellybean glue. The Dope Scope is a capable device, but it’s marketed towards the 1337 utilikilt-wearing, The Prodigy-blasting pentesters of the world. It is, therefore, a ripoff. [Steve] can build his version for $6 in materials.

The core of the build is an ESP-based carrier board built for NodeMCU. This board is available for $3.77 in quantity one, with free shipping. A $2 SPI OLED display is the user interface, and the rest of the circuit is just some perfboard and a few wires.

The software is based on platformio, and dumps all the WiFi info you could want over the serial port or displays it right on the OLED. It’s a brilliantly simple device for War Walking, and the addition of a small LiPo makes this a much better value than the same circuit with a larger pricetag.

How to Get Started with the ESP32

ESP32 is the hottest new wireless chip out there, offering both WiFi and Bluetooth Low Energy radios rolled up with a dual-core 32-bit processor and packed with peripherals of every kind. We got some review sample dev boards, Adafruit and Seeed Studio had them in stock for a while, and AI-Thinker — the company that makes the most popular ESP8266 modules — is starting up full-scale production on October 1st. This means that some of you have the new hotness in your hands right now, and the rest of you aren’t going to have to wait more than a few more weeks.

As we said in our first-look review of the new chip, many things are in a state of flux on the software side, but the basic process of writing, compiling, and flashing code to the chip is going to remain stable. It’s time to start up some tutorials!

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RC Drag Racing Christmas Tree and Speed Trap

In the drag racing world, a Christmas tree is the post at the start line that sequentially lights up a set of yellow lights followed shortly after by a green light to tell the drivers to go, the lights obviously giving it its seasonal name. Included at the base of the tree are lasers to detect the presence of the cars.

[Mike] not only made his own Christmas tree for his RC cars, but he even made an end-of-track circuit with LED displays telling the cars how long they took. Both start and finish hardware are controlled by Pololu Wixel boards which has TI CC2511F32 microcontrollers with built-in 2.4 GHz radios for wireless communications.

In addition to the LEDs, the Christmas tree has a laser beam using a 650nm red laser diode for each car at the start line that’s aimed at a TEPT5600 phototransistor. If a car crosses its beam before the green light then a red light signals the car’s disqualification.

The end-of-track circuit has 7-segment displays for each car’s time. [Mike] designed the system so that the Christmas tree’s microcontroller tells the end-of-track circuit’s microcontroller when to reset the times, start the times, and clear the times should there be a disqualification. The finish line controller has lasers and phototransistors just like the starting line to stop the timers.

Oh, and did we mention that he also included 1980’s car racing game sounds? To see and hear it all in action check out the video after the break. If the cars seem a little drunk it’s because pushing left or right on the controller turns the wheel’s fully left or right.

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Drone Flies 12 cm on Wireless Power

[Sam M] wrote in with a quick proof-of-concept demo that blows our socks off: transferring enough power wirelessly to make a small quadcopter take flight. Wireless power transfer over any real distance still seems like magic to us. Check out the videos embedded below and you’ll see what we mean.

What’s noteworthy about this demo is that neither the transmitter nor the receiver are particularly difficult to make. The transmitting loop is etched into a PCB, and the receiver is made of copper foil tape. Going to a higher frequency facilitates this; [Sam M] is using 13.56 MHz instead of the kilohertz that most power-transfer projects use. This means that all the parts can be smaller and lighter, which is obviously important on a miniature quadrotor.

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