Make The Time To Fix Your Time Debt

February 6, 2019 by 23 Comments

You’re too busy to read more than this intro paragraph. We all are. Your interest might get piqued enough to skim, but you can’t read the full thing. Our lives all resemble the White Rabbit, constantly late for our next thing, never enjoying the current thing. You feel simultaneously super productive and yet never productive enough to be satisfied. You yearn for a Jarvis that can automate the mundane aspects of your projects, and yet the prospect of building a Jarvis causes anxiety about not having enough time for yet another project. You see another YouTuber showing off not only a great build but also impressive video production and editing skills. You are suffering from Time Debt, and the solution requires as much discipline and tenacity as escaping from financial debt.

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Open Source LIDAR Lets You Get Down To The Nitty Gritty

February 6, 2019 by 11 Comments

If you’re unfamiliar with LIDAR, you might have noticed it sounds a bit like radar. That’s no accident – LIDAR is a backronym standing for “light detection and ranging”, the word having initially been created as a combination of “light” and “radar”. The average person is most likely to have come into contact with LIDAR at the business end of a police speed trap, but it doesn’t have to be that way. Unruly is the open source LIDAR project you’ve been waiting for all along.

Unlike a lot of starter projects, LIDAR isn’t something you get into with a couple of salvaged LEDs and an Arduino Uno. We’re talking about measuring the time it takes light to travel relatively short distances, so plenty of specialised components are required. There’s a pulsed laser diode, and a special hypersensitive avalanche photodiode that operates at up to 130 V. These are combined with precision lenses and filters to ensure operation at the maximum range possible. Given that light can travel 300,000 km in a second, to get any usable resolution, a microcontroller alone simply isn’t fast enough to cut it here. A specialized  time-to-digital converter (TDC) is used to time how long it takes the light pulse to return from a distant object. Unruly’s current usable resolution is somewhere in the ballpark of 10 mm – an impressive feat.

It’s a complicated project, requiring the utmost attention to detail to get any results at all. The team behind Unruly have done a great job of both designing and documenting the project. It’s great to see an open source LIDAR package in the wild, giving hackers more options than just the pre-baked commercial modules on the market. We can’t wait to see where the project goes next.

For more on LIDAR, check out last week’s Hackaday podcast – we cover Unruly, as well as a handful of other standout projects in the field.

The WiFi Phone That Respects Your Right To Repair

February 6, 2019 by 49 Comments

Phones are getting increasingly more complex, more difficult to repair, and phone manufacturers don’t like you tinkering with their stuff. It’s a portable version of a John Deere tractor in your pocket, and Apple doesn’t want you replacing a battery by yourself. What if there was a phone that respected your freedom? That’s the idea behind the WiPhone, and soon it’s going to be be a crowdfunding campaign. Yes, you will soon be able to buy a phone that respects your freedom.

We took a look at the WiPhone a few months ago, and the idea was solid: make a simple, cheap, handheld device based on the ESP32 WiFi/Bluetooth wonder microcontroller. There are a few other various bits of electronic ephemera for scanning the buttons, an audio codec, and a speaker driver, but the basics of the build are just an LCD and ESP32. The entire idea of this phone is to make calls through WiFi, and given the state of VoIP, it’s a marketable product.

Astute readers may notice that the WiPhone doesn’t have a cellular modem. Yes, this is true, but putting a baseband in a small, low-volume project is incredibly hard. You’re limited to 2G if you don’t want to deal with Broadcom or Qualcomm, and they’re not going to be interested in you if you’re not moving a hundred thousand units, anyway. Also, you’ve got service plans to deal with, multi-country radios, and you’re probably next to a trusted WiFi network right now, anyway.

The WiPhone is designed to be hackable, with daughter boards that turn it into a rainbow or RC car, and easy to assemble. It’s also going to be a crowdfunding campaign at the end of the month. If you want a phone that respects your right to repair, this is the project to look at, even if you don’t need a cellular modem all the time.

This Vintage Phone Goes Cellular

February 5, 2019 by 8 Comments

Way back in the good old days, life ran at a slower pace. It took us almost a decade to get to the moon, and dialling the phone was a lazy affair which required the user to wait for the rotary mechanism to rewind after selecting each digit. Eager to bring a taste of retro telephony into the modern era, [Marek] retrofitted this vintage Polish telephone with a GSM upgrade.

The phone [Marek] salvaged had already been largely gutted, so there was little to lose in the transformation. A Motorola D15 GSM module was sourced from an alarm system to provide a network connection to the project. An Atmega328 was then used to translate the rotary dial mechanics into something more usable by the cellular module.

Attention to detail can really make a project shine, and [Marek] didn’t skimp in this area. The original ringer was rewound to operate with a half H-bridge at a lower voltage more suitable to the modern electronics inside. The microcontroller also helped out by using its PWM hardware to simulate a dialtone and the characteristic sound of pulse dialling.

It’s always nice to see retro hardware given a new lease on life. Unfortunately, GSM networks aren’t long for this world, so a further update may be required before long. These old phones have plenty of potential, as we’ve seen before.

The Design And Construction Of A Tribute To A Bomber Pilot

February 5, 2019 by 11 Comments

Decades ago, [wilmracer]’s grandfather was piloting a B-17 over the Rhine, and as it goes, aviation runs in families. Now, more than 70 years later [wilmracer] is deep, deep into remote controlled aircraft, and he’s building an exacting scale model of the B-17G his grandfather flew on his last bombing mission over Europe.

This is a scratch build, with the design taken directly from the plans and schematics of a B-17. [wilmracer] has already paid the money to go up in the preserved B-17 Aluminum Overcast to get a better idea of the layout, and now he’s deep into cutting foam and bending balsa sheets. The first part of the build was arguably the hardest, and the main landing gear was expertly constructed out of aluminum tube and linear servos. The horizontal stab follows traditional building techniques of foam and carefully sanded balsa sheets. The fuselage is impressive, with the formers built out of foam, and eventually covered in 1/16″ balsa and wrapped in fiberglass.

If you’re going to do a large-scale model airplane, that also means you’ve got to do detailing. That means steam gauges rendered in 3D printed parts. [wilmracer] is modeling the cockpit and the machine guns in 1:9 scale. This is going to be an awesome build, and yes, there will eventually be plans.

Of course, this isn’t the biggest small B-17 ever built. That record goes to the 1:3 scale Bally Bomber, a real, not remote controlled plane built over the course of two decades by [ Jack Bally]. This is a real plane with a 34 foot wingspan that weighs 1800 pounds. Yes, it flies, and it went to Oshkosh last summer. Remote control really is the way to go with something like this, though: you can appease the rivet counters, put more power on the props, and you don’t need to worry too much about pesky things like regulations and laws. We’re looking forward to see where this project goes, and to the sound of a great PLA overcast thundering over the treetops.

A Lemon Battery Via 3D Printing

February 5, 2019 by 16 Comments

There are a whole bunch of high school science experiments out there that are useful for teaching students the basics of biology, physics, and chemistry. One of the classics is the lemon battery. [iqless] decided to have a play with the idea, and whipped up a little something for his students.

The basic lemon battery is remarkably simple. Lemon juice provides the electrolyte, while copper and and zinc act as electrodes. This battery won’t have a hope of charging your Tesla, but you might get enough juice to light an LED or small bulb (pun intended).

[iqless] considered jamming electrodes directly into lemons to be rather unsophisticated. Instead, an electrolyte tray was 3D printed. The tray can be filled with lemon juice (either hand-squeezed or straight from a bottle) and the tray has fixtures to hold copper pennies and zinc-plated machine screws to act as the electrodes. The tray allows several cells to be constructed and connected in series or parallel, giving yet further teaching opportunities.

It’s a fun twist on a classroom staple, and we think there are great possibilities here for further experimentation with alternative electrolytes and electrode materials. We’d also love to see a grown-up version with a large cascade of cells in series for lemon-based high voltage experiments, but that might be too much to ask. There’s great scope for using modern maker techniques in classroom science – we’ve discussed variations on the egg drop before. Video after the break.

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Cheap Power Over Ethernet For The ESP32

February 5, 2019 by 8 Comments

While most projects we see with the ESP32 make use of its considerable wireless capabilities, the chip can be connected to the wired network easily enough should you have the desire to do so. [Steve] liked the idea of putting his ESP32s on the wired network, but found the need for a secondary power connection burdensome. So he took it upon himself to modify some cheap Power Over Ethernet (PoE) hardware and create a single-cable solution (Google Translate).

[Steve] bought a PoE module intended for security cameras and ran a close eye over the board to figure out what kind of hardware it was using to generate the nominal 12 V output. He identified an MP2494 step-down converter, and with the datasheet in hand found how the output voltage is configured by changing the values of resistors in the circuit. Swapping out the stock 21.5 kΩ resistor for a 57.1 kΩ one changed the output of the converter to the 5 V necessary for his electronics.

But of course that was only half of the problem solved; he still had to connect the Ethernet side of the PoE device to the Waveshare LAN8720 board that’s providing Ethernet for the ESP32. So he removed the RJ45 jack from the LAN8720 completely, and wired that directly to the connector on the PoE board. Helpfully, the PoE board had all the pins labeled on the bottom side so this wasn’t nearly as tricky to figure out as you might expect (if only it was always that easy).

We’ve previously covered the Waveshare LAN8720 board for anyone who’s interested in the ins and outs of getting their ESP32 talking Ethernet. If you’re wondering how you can put PoE to work for you, our very own [Jonathan Bennett] has been showing off his home Raspberry Pi infrastructure which makes extensive use of the new PoE hat.