Millenium Falcon HID: Get Unity To Talk To Teensy

August 15, 2019 by Inderpreet Singh 11 Comments

Here’s one that proves a hardware project can go beyond blinking LEDs and dumping massive chunks of data onto a serial console. Those practices are fine for some, but [dimtass] has found a more elegant hack for a more civilized age. His 3D Millennium Falcon model gets orientation data from his IMU as an an HID device.

The hardware involved is an MPU6050 6-axis sensor that is interfaced with a Teensy 3.2 board. [dimtass] documents his approach to calibrating the IMU going a bit further by using a Python script to generate offsets. We’ve advocated using Jupyter notebooks in the past and this is a good example of Jupyter plotting the data and visualizing the effect of the offsets in a second pass.

When in action, the Teensy reads IMU data and sends it over a USB RAW HID interface. For the uninitiated, HID transfers are more reliable than USB CDC transfers (virtual serial port) because they use smaller data chunks per event/transaction and usually don’t require special drivers. On the computer side, [dimtass] has written a small application that gets the IMU values over the RAW HID and then provides it to the visualization application.

A 3D Millennium Falcon model is rendered in Unity, the popular open source game development engine. Even though Unity has an API, this particular approach is more OS specific using a shared-memory technique. The HID application writes to a file (/tmp/hid-shared-buffer) which is then read by Unity to make orientation changes to the rendered model.

[dimtass] provides lots of details on the tools used to bring his project to life and it can be a great starting point for more projects that need interfacing sensors with a visualization system. We have seen ways to turn a person’s head into a joystick and if you need a deeper dive into Unity, look no further.

Continue reading “Millenium Falcon HID: Get Unity To Talk To Teensy” →

PaperLedger: An E-Ink Cryptocurrency Ticker

August 12, 2019 by Tom Nardi 6 Comments

For a long time it seemed like e-ink displays were outside the reach of us lowly hackers, as beyond the handful of repurposed Kindles that graced these pages, we saw precious few projects utilizing this relatively exotic display. But that’s changed over the last couple of years, and we’re thrilled to start seeing hackers bend this incredible technology to their will.

A perfect example is PaperLedger, an entry into the 2019 Hackaday Prize by [AIFanatic]. This wireless device is designed to display the current price of various cryptocurrencies on its 2.9-inch e-ink screen and provide audible price alerts with its built-in speaker. It even has a web portal where users can configure the hardware or view more in-depth price information.

The PaperLedger is based on the TTGO T5 V2.2 ESP32, but it looks like [AIFanatic] is in the process of spinning up a new board for the MIT licensed project to address some nagging issues for this particular application. Unfortunately, it doesn’t look like there are any pictures of the new board yet, but a description of the changes on the Hackaday.IO page shows that most of the work seems to be going into improving support for running on batteries.

Even if you’re not interested in cryptocurrency, the PaperLedger looks like a fantastic little e-ink monitor for pretty much anything else you’d like to keep a close eye on. The GPLv3 licensed firmware is available on the project’s GitHub page, so expanding or completely changing the device’s functionality shouldn’t be too tricky for anyone with a desire to do so and a working knowledge of C++.

We’ve seen several projects using the various TTGO boards that mate an ESP32 with a display at this point, and it looks like a great platform to check out if you want to push some data to a little WiFi screen with the minimum amount of hassle.

3D Printing Makes Modular Payload For Model Rocket

August 9, 2019 by Donald Papp 2 Comments

Putting payloads into model rockets can be more complex than simply shoving stuff into an open spot, so [concretedog] put some work into making a modular payload tube for his current rocket. The nose cone for his rocket is quite large, so he opted to give it a secure payload area that doesn’t compromise or interfere with any of the structural or operational bits such as the parachute.

The payload container is a hollow tube with a 3D printed threaded adaptor attached to one end. Payload goes into the tube, and the tube inserts into a hole in the bulkhead, screwing down securely. The result is an easy way to send up something like a GPS tracker, possibly with a LoRa module attached to it. That combination is a popular one with high-altitude balloons, which, like rockets, also require people to retrieve them after not-entirely-predictable landings. LoRa wireless communications have very long range, but that doesn’t help if there’s an obstruction like a hill between you and the transmitter. In those cases, a simple LoRa repeater attached to a kite, long pole, or drone can save the day.

We’ve seen [concretedog]’s work before, when he designed stackable PCBs intended to easily fit inside model rocket bodies, allowing for easy integration of microcontroller-driven functions like delayed ignitions or altimeter triggers. Better development tools, hardware, and 3D printing has really helped make smarter rocketry more accessible to hobbyists.

This WiFi Spoofing Syringe Is For External Use Only

August 8, 2019 by Tom Nardi 6 Comments

A browse through his collected works will tell you that [El Kentaro] loves to build electronics into interesting enclosures, so when he realized there’s enough room inside a 150 ml plastic syringe to mount an ESP8266, a battery, and a copious amount of RGB LEDs, the “Packet Injector” was the inescapable result.

Granted, the current incarnation of this device doesn’t literally inject packets. But [El Kentaro] wasn’t actually looking to do anything malicious, either. The Injector is intended to be a fun gag for him to bring along to the various hacker cons he finds himself at, like his DEAUTH “bling” necklace we saw at DEF CON 26, so having any practical function is really more icing on the cake than a strict requirement.

In the end, the code he came up with for the Adafruit Feather HUZZAH that uses the FakeBeaconESP8266 library to push out fictitious networks on demand. This is a trick we’ve seen used in the past, and makes for a relatively harmless prank as long as you’re not pumping out any particularly unpleasant SSIDs. In this case, [El Kentaro] punctuates his technicolor resplendency with beacons pronouncing “The WiFi Doctor is Here.”

But the real hack here is how [El Kentaro] controls the device. Everything is contained within the syringe chamber, and he uses a MPL3115A2 I2C barometric pressure sensor to detect when it’s being compressed. If the sensor reads a pressure high enough over the established baseline, the NeoPixel Ring fires up and the fake beacon frames start going out. Ease up on the plunger, and the code detects the drop in pressure and turns everything back off.

If this build has piqued your interest, [El Kentaro] gave a fascinating talk about his hardware design philosophy during the WOPR Summit that included how he designed and built some of his “greatest hits”; including a Raspberry Pi Zero enclosure that was, regrettably, not limited to external use.

New Teensy 4.0 Blows Away Benchmarks, Implements Self-Recovery, Returns To Smaller Form

August 7, 2019 by Ted Yapo 177 Comments

Paul Stoffregen did it again: the Teensy 4.0 has been released. The latest in the Teensy microcontroller development board line, the 4.0 returns to the smaller form-factor last seen with the 3.2, as opposed to the larger 3.5 and 3.6 boards.

Don’t let the smaller size fool you; the 4.0 is based on an ARM Cortex M7 running at 600 MHz (!), the fastest microcontroller you can get in 2019, and testing on real-world examples shows it executing code more than five times faster than the Teensy 3.6, and fifteen times faster than the Teensy 3.2. Of course, the new board is also packed with periperals, including two 480 Mbps USB ports, 3 digital audio interfaces, 3 CAN busses, and multiple SPI/I2C/serial interfaces backed with integrated FIFOs. Programming? Easy: there’s an add-on to the Arduino IDE called Teensyduino that “just works”. And it rings up at an MSRP of just $19.95; a welcomed price point, but not unexpected for a microcontroller breakout board.

The board launches today, but I had a chance to test drive a couple of them in one of the East Coast Hackaday labs over the past few days. So, let’s have a closer look.

Continue reading “New Teensy 4.0 Blows Away Benchmarks, Implements Self-Recovery, Returns To Smaller Form” →

Sniffed Transformer Puts Wired Doorbell Online

August 6, 2019 by Tom Nardi 30 Comments

There’s certainly no shortage of “smart” gadgets out there that will provide you with a notification, or even a live audiovisual stream, whenever somebody is at your door. But as we’ve seen countless times before, not everyone is thrilled with the terms that most of these products operate under. Getting a notification on your phone when the pizza guy shows up shouldn’t require an email address, credit card number, or DNA sample.

For [Nick Touran], half the work was already done. There was already a traditional wired doorbell in his home, he just had to come up with a minimally invasive way to link it with Home Assistant. He reasoned that he could tap into the low-voltage side of the doorbell transformer and watch for the telltale fluctuations that would indicate the bell was doing its thing. The ESP8266 has an ADC to measure voltage and WiFi to connect to Home Assistant, so it seemed like the perfect bridge between old and new.

Of course, as with any worthwhile project, it ended up being a bit more complicated. Wired doorbells generally operate on 16-24 VAC, and [Nick] knew if he tried to put his Wemos D1 across the line he’d release the critical Magic Smoke. What he needed was a voltage divider circuit that would take low-voltage AC and drop it to an even lower DC voltage that the microcontroller could cope with.

The simple circuit [Nick] comes up with cuts the voltage way down and removes the negative component completely. So what was originally 18.75 VAC turned into a series of 60 Hz blips at 2.4 VDC; perfect for feeding into a microcontroller ADC. With a baseline to work from, he could then write some code that would watch for variations in this signal to determine when the bell was ringing.

Or at least, that was the idea. While the setup worked well enough on the bench, its performance in the real-world left something to be desired. If his house guest had a heavy hand, it worked great. But a quick tap of the doorbell button would tend to go undetected. After investigating the issue, [Nick] found that he needed to use some software trickery to ensure the ESP8266 was able to keep up with the speedy signal. Once he was able to reliably detect short and long button presses, the rest was just a simple matter of sending an MQTT message to his automation system.

Compared to the hoops we’ve seen other hackers have to jump through to smarten up their doorbells, we think [Nick] got off fairly easy. This project is also an excellent example of how learning about circuit design and passive components can still come in handy in the Arduino Era.

Continue reading “Sniffed Transformer Puts Wired Doorbell Online” →

Cat Feeder Adds Metrics To Meow Mix

August 5, 2019 by Kristina Panos 16 Comments

If there’s one thing any cat will work for, it’s food. Usually, this just consists of meowing and/or standing on your chest until you give up the goods. [DynamicallyInvokable] has a beautiful cat, Emma, who meows loudly for food at obscene hours of the morning. As she ages, it’s getting harder and more important to control her weight. Clearly, it was time to build the ultimate automatic cat feeder—one that allows him to get lazy while at the same time getting smart about Emma’s weight.

After a year and a half of work, the feeder is complete. Not only does it deliver the goods several times a day, it sends a heap of data to the cloud about Emma’s eating habits. There’s a scale built into the platform, and another in the food bowl. Together, they provide metrics galore that get automatically uploaded to AWS. Everything is controlled with an ESP32 Arduino, including a rainbow of WS2812s that chases its tail around the base of the feeder. The faster it goes, the closer it is to feeding time.

The best part about this unique feeder is that nearly every piece is 3D printed, including the gears. Be sure to check out the build gallery, where you can watch it come together piece by piece. Oh, and claw your way past the break to see Emma get fed.

Emma doesn’t have to worry about sharing her food. If she did, maybe [DynamicallyInvokable] could use facial recognition to meet the needs of multiple cats.

Continue reading “Cat Feeder Adds Metrics To Meow Mix” →