Panel Meter-To-Bluetooth Hack Hijacks The Display Segments

There are a proliferation of cheap digital meter modules available online for pocket money prices. Current, voltage, frequency, or combinations thereof can all be yours for just a few dollars and a wait for shipping. Unfortunately though these meters are all self-contained units. They do not have a serial port or other interface through which you can log their readings.

This failing was not an obstacle for [Scott Harden], though. He simply added a Bluetooth interface to his combined voltage and current meter module by using an ATmega328 microcontroller to capture the signals sent to the module’s display LEDs and interpret them into readings for his Bluetooth module. He details the process of reverse engineering the meter, and his build. The result is an intriguing mess of wires with a DIP ATmega hanging on their ends. But it performs the task requested of it admirably and when mounted in a project box you would not know what lurks within.

He has made his code for the project available in his GitHub repository, we can see that this could be a valuable technique for use with other similar displays. In the video below the break he gives us a full run-down, as if his comprehensive write-up was not enough.

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ESP32 Hands-On: Awesome Promise

The ESP32 is looking like an amazing chip, not the least for its price point. It combines WiFi and Bluetooth wireless capabilities with two CPU cores and a decent hardware peripheral set. There were modules in the wild for just under seven US dollars before they sold out, and they’re not going to get more expensive over time. Given the crazy success that Espressif had with the ESP8266, expectations are high.

And although they were just formally released ten days ago, we’ve had a couple in our hands for just about that long. It’s good to know hackers in high places — Hackaday Superfriend [Sprite_tm] works at Espressif and managed to get us a few modules, and has been great about answering our questions.

We’ve read all of the public documentation that’s out there, and spent a week writing our own “hello world” examples to confirm that things are working as they should, and root out the bugs wherever things aren’t. There’s a lot to love about these chips, but there are also many unknowns on the firmware front which is changing day-to-day. Read on for the full review.

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Hacking a Dollar Store Bluetooth Device

Hardware hackers are always looking for devices to tear apart and scavenge from. It’s hardly a secret that purchasing components individually is significantly more expensive than the minuscule cost per unit that goes along with mass manufacturing. Bluetooth devices are no exception. Sure, they’re not exactly a luxury purchase anymore, but they’re still not dirt cheap either.

Luckily for [Troy Denton], it seems dollar stores have started carrying a Bluetooth camera shutter for just a few dollars (it was three bucks, perhaps the dollar store actually means divisible-by). The device is designed to pair with a smart phone, and has two buttons allowing you to control the camera from afar. The fact that it works at all at that price is a small miracle, but the device also has potential for hacking that adds to its appeal. Continue reading “Hacking a Dollar Store Bluetooth Device”

Hand Waving Unlocks Door

Who doesn’t like the user interface in the movie Minority Report where [Tom Cruise] manipulates a giant computer screen by just waving his hands in front of it? [AdhamN] wanted to unlock his door with hand gestures. While it isn’t as seamless as [Tom’s] Hollywood interface, it manages to do the job. You just have to hold on to your smartphone while you gesture.

The project uses an Arduino and a servo motor to move a bolt back and forth. The gesture part requires a 1sheeld board. This is a board that interfaces to a phone and allows you to use its capabilities (in this case, the accelerometer) from your Arduino program.

The rest should be obvious. The 1sheeld reads the accelerometer data and when it sees the right gesture, it operates the servo. It would be interesting to do this with a smart watch, which would perhaps look a little less obvious.

We covered the 1sheeld board awhile back. Of course, you could also use NFC or some other sensor technology to trigger the mechanism. You can find a video that describes the 1sheeld below.

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Convert Any USB Keyboard to Bluetooth

[DastardlyLabs] saw a video about converting a PS/2 keyboard to Bluetooth and realized he didn’t have any PS/2 keyboards anymore. So he pulled the same trick with a USB keyboard. Along the way, he made three videos explaining how it all works.

The project uses a stock DuinoFun USB mini host shield with a modification to allow it to work on 5V. An Arduino mini pro provides the brains. A FT-232 USB to serial board is used to program the Arduino. A standard Bluetooth module has to have HID firmware installed. [Dastardly] makes a homemade daughterboard–er, shield–to connect it to the Arduino.

The result is a nice little sandwich with a USB plug, a Bluetooth antenna, and some pins for reprogramming if necessary. Resist the urge to solder the Bluetooth board in–since it talks on the same port as the Arduino uses for programming, you’ll have to remove it before uploading new code.

If you need help reprogramming the HC-05 Bluetooth module, we’ve covered that before. This project drew inspiration from [Evan’s] similar project for PS/2 keyboards.

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Retrofitted Retro Radio

In a world full of products that are only used for a brief time and then discarded, it gives a lot of us solace to know that there was a time when furniture was made out of solid wood and not particle board, or when coffee makers were made out of metal and not plastic. It’s hard to say exactly what precipitated the change to our one-time-use culture, but in the meantime there are projects that serve to re-purpose those old, durable products from another time so that they can stay relevant in today’s ever-changing world. [Jose]’s new old radio is a great example of this style of hack.

[Jose] had a 1970s-era single-speaker radio that he found in a thrift store. The first thought that he had to get the aesthetically pleasing radio working again was to install a Bluetooth receiver into the radio’s amplifier. This proved to be too time-consuming of a task, and [Jose] decided to drive the Bluetooth module off of the power circuit for the light bulb. He built a 6V AC to 4.2V DC circuit, swapped over the speaker cable, and started listening to his tunes. The modifications he made aren’t destructive, either. If he wants, he will be able to reconnect the original (and still functional) circuitry back to the speaker and pretend he’s back in 1970.

While this isn’t the most intricate hack we’ve ever featured, it’s always refreshing to see someone get use out of an old piece of technology rather than send it off to the landfill with all of our Pentium IIs or last year’s IKEA shelves that have already fallen apart. And even if the 70s aren’t your era of choice, perhaps something newer will inspire you to bust a move.

Bluetooth HID Gamepad And HC-05 Serial Hack

“Which came first, the chicken or the egg?” Don’t bother us with stupid questions, they both co-evolved into the forms that we now serve up in tasty sandwiches or omelets, respectively. “Which came first, the HC-05 serial-flash-hack, or the wireless Bluetooth Gamepad?” Our guess is that [mitxela] wanted to play around with the dirt-cheap Bluetooth modules, and that building the wireless controller was an afterthought. But for that, it’s a well-done afterthought! (Video below the break.)

It all starts with the HC-05 Bluetooth module, which is meant to transfer serial data, but which can be converted into a general-purpose device costing ten times as much with a simple Flash ROM replacement. The usual way around this requires bit-banging over a parallel port, but hackers have worked out a way to do the same thing in bit-bang mode using a normal USB/Serial adapter. The first part of [mitxela]’s post describes this odyssey.

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