Year: 2018

LoRa System Commands Drones From A Distance

May 5, 2018 by 11 Comments

LoRa has been making quite a stir in hacker circles over the past couple of years, as it offers a fascinating combination of long range, low power, and low cost. It does this by using spread spectrum techniques on unlicensed frequency bands, meaning it can send data a surprising distance and that you don’t need a radio license to use it. It is mainly used for Internet of Things things, but [Paweł Spychalski] has other ideas: he’s building a system to use it to control a quadcopter drone over distances of 5 kilometers or more. That’s an ambitious aim, considering that the parts he is using cost only a few bucks.

He’s using an off-brand Adafruit Feather LoRa board and a couple of home-made antennas with his own software that takes the data from the Taranis control port of the RC controller, encodes it and chirps it out over the LoRa radio. At the other end, a similar radio receives and decodes the data, feeding it out to the drone.

This is definitely still a work in progress, but he has got it working, flying his drone over the link, keeping control of it out to several hundred meters. At the moment, he can’t go much further as it seems that his LoRa radio is being overwhelmed by the video link on the drone, but he is working on changing the frequency spread & hopping and using a better antenna to provide longer range. We’ve seen some interesting stuff from [Pawel] before, like his DIY telemetry system, so this project is worth keeping an eye on if you are a drone fan.

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Low-Cost Eye Tracking With Webcams And Open-Source Software

May 5, 2018 by 10 Comments

“What are you looking at?” Said the wrong way, those can be fighting words. But in fields as diverse as psychological research and user experience testing, knowing what people are looking at in real-time can be invaluable. Eye-tracking software does this, but generally at a cost that keeps it out of the hands of the home gamer.

Or it used to. With hacked $20 webcams, this open source eye tracker will let you watch how someone is processing what they see. But [John Evans]’ Hackaday Prize entry is more than that. Most of the detail is in the video below, a good chunk of which [John] uses to extol the virtues of the camera he uses for his eye tracker, a Logitech C270. And rightly so — the cheap and easily sourced camera has remarkable macro capabilities right out of the box, a key feature for a camera that’s going to be trained on an eyeball a few millimeters away. Still, [John] provides STL files for mounts that snap to the torn-down camera PCB, in case other focal lengths are needed.

The meat of the project is his Jevons Camera Viewer, an app he wrote to control and view two cameras at once. Originally for a pick and place, the software can be used to coordinate the views of two goggle-mounted cameras, one looking out and one focused on the user’s eye. Reflections from the camera LED are picked up and used to judge the angle of the eye, with an overlay applied to the other camera’s view to show where the user is looking. It seems quite accurate, and plenty fast to boot.

We think this is a great project, like so many others in the first round of the 2018 Hackaday Prize. Can you think of an awesome project based on eye tracking? Here’s your chance to get going on the cheap.

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Fail Of The Week: Never Assume All Crystals Are Born Equal

May 5, 2018 by 23 Comments

You should be used to our posting the hacks that didn’t quite go according to plan under our Fail Of The Week heading, things that should have worked, but due to unexpected factors, didn’t. They are the fault, if that’s not too strong a term, of the person making whatever the project is, and we feature them not in a spirit of mockery but one of commiseration and enlightenment.

This FOTW is a little different, because it reveals itself to have nothing to do with its originator. [Grogster] was using the widely-available HC-12 serial wireless modules, or clones or even possibly fakes thereof, and found that the modules would not talk to each other. Closer inspection found that the modules with the lack of intercommunication came from different batches, and possibly different manufacturers. Their circuits and components appeared identical, so what could possibly be up?

The problem was traced to the two batches of modules having different frequencies, one being 37 kHz ahead of the other. This was in turn traced to the crystal on board the off-frequency module, the 30 MHz component providing the frequency reference for the Si4463 radio chip was significantly out of spec. The manufacturer had used a cheap source of the component, resulting in modules which would talk to each other but not to the rest of the world’s HC-12s.

If there is a lesson to be extracted from this, it is to be reminded that even when cheap components or modules look as they should, and indeed even when they appear to work as they should, there can still be unexpected ways in which they can let you down. It has given us an interesting opportunity to learn about the HC-12, with its onboard STM8 CPU and one of the always-fascinating Silicon Labs radio chips. If you want to know more about the HC-12 module, we linked to a more in-depth look at it a couple of years ago.

Thanks [Manuka] for the tip.

Hardware Acceleration In The Cloud

May 5, 2018 by 30 Comments

Computers are great at a lot of things. However, general-purpose computers can benefit from help on certain tasks, which is why your video card and sound card both have their own specialized hardware to offload the CPU. If Accelize has its way, some of your hardware acceleration will be done in the cloud. Yes, we know. The cloud is the buzzword of the week and we are tired of hearing about it, too. However, this service is a particularly interesting way to add FPGA power to just about any network-connected CPU.

Currently, there are only four accelerators available, including a hardware-assisted random number generator, a GZIP accelerator, an engine for rapidly searching text, and a BMP to JPEG converter. The company claims, for example, that the search engine can find 2500 entries in the 60 GB Wikipedia archive in 6 minutes. They claim a traditional CPU would take over 16 days to do the same task. The BMP to JPEG converter can process faster than required to feed real-time HD video.

The cloud, in this case, is FPGA resources hosted in the Amazon cloud or in the OVH public cloud. They’ll clearly charge for the service at some point using a “coin” system. However, right now they are letting you sign up with nothing more than an e-mail address and crediting your account with 50,000 coins. Apparently, coins are 1,000 for one dollar.

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Simple Home-built Projection Clock Projects Time

May 5, 2018 by 16 Comments

There are plenty of cheap projection clocks available, but as [Thomas Pototschnig] points out in this project, where’s the fun in just buying something? He set out to build a cheap projection clock using a small LCD screen, a cheap LED backlight, and a cheap lens. (Website seems down, try this link courtesy of the Internet Archive if it fails.) Cheap is the order of the day here, and [Thomas] succeeded admirably, creating a design that can be made with a couple of cheap PCBs, a 3D printer and the other parts mentioned above. He does a nice job of laying out his thinking in this design, showing how he calculated the projection path and made other decisions. His project has room to grow as well: it runs from an Arduino compatible STM32 that could handle many things other than showing the time if you were inclined to expand the project further.

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Giving An LED Bulb Some Smarts

May 5, 2018 by 54 Comments

How many of your projects been spawned purely out of bored daydreaming? For want of something more productive to do, [dantheflipman] hacked a standard LED bulb from Wal-Mart into a smart bulb.

After pulling it apart, they soldered wires to the threaded socket and added a connector for a Hi-Link hlk-pm01 power module. The output caps at 5 V and 600 mA, but who says this was going to be a searchlight? A Wemos D1 Mini clone slides nicely beside the power module, and stacked on top is a NeoPixel Jewel 7. [dantheflipman] admits he has yet to add a capacitor to ahead of the Jewel, so we’ll see how long the LEDs last. Crammed back together, the bulb is controlled via a prototype Blynk app. Good enough for a quick hack.

[dantheflipman] is upfront about messing with mains voltages: don’t do it unless you absolutely know what you’re doing. In this case, he has taken care with their soldering and epoxied all wire and solder joints to be sure nothing will come loose and short, and a ‘stress test’ is forthcoming.

Smart bulbs are cool no matter how you slice it, so a little more insight into how smart bulbs work with some of the nitty gritty that goes into hacking them might sate your thirst for knowledge.

[Via /r/arduino]

Super Simple, Super Cheap FPV Drone Tracking

May 4, 2018 by 20 Comments

What’s more disruptive to the drone first-person view (FPV) experience than dropouts in your video feed when you’re in the middle of a race? Probably nothing, and there’s probably also not much you can do about it. Or is there? Might a simple tracker based on RSSI help keep your video signal locked in?

Honestly, we’re not sure it would, but we think it’s pretty nifty to see [FlyerFpv]’s tracker following his drone around. The idea is simple and uses the full-diversity FPV receiver he already has. Diversity receivers constantly monitor signal strength from multiple antennas to determine which one to listen to, which improves reception quality. [FlyerFpv] sends the RSSI outputs to analog inputs on an Arduino which drives a servo to keep the signals as close to each other as possible. The Arduino and the DC-DC converter needed to power it fit nicely inside the receiver case with no modifications, which is a nice touch. With a 3D-printed servo mount and some fancy directional antennas, the setup keeps pretty good track of his drone now. See it in action below.

Sure, the response could be snappier, and we’d love to see another receiver and servo added to track pitch as well as yaw. For a first pass, we think it’s great, but [FlyerFpv] should enjoy it while he can in case AI takes over our flying fun soon.

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