Year: 2020

New Part Day: Battery-Less NFC E-Paper Display

March 22, 2020 by 30 Comments

Waveshare, known for e-ink components aimed at hobbyists among other cool parts, has recently released a very interesting addition to their product line. This is an enclosed e-ink display which gets updated over a wireless NFC connection. By that description, nothing head-turning, but the kicker is that there is no battery inside the device at all, as it harvests the energy needed from the wireless communication itself.

Just like wireless induction charging in certain smartphones, the communication waves involved in NFC can generate a small current when passing through a coil, located on this device’s PCB. Since microcontrollers and e-ink displays consume a very small amount of current compared to other components such as a backlit LCD or OLED display, this harvested passive energy is enough to allow the display to update. And because e-paper requires no power at all to retain its image, once the connection is ended, no further battery backup is needed.

The innovation here doesn’t come from Waveshare however, as in 2013 Intel had already demoed a very similar device to promising results. There’s some more details about the project, but it never left the proof of concept stage despite being awarded two best paper awards. We wonder why it hadn’t been made into a commercial product for 5 years, but we’re glad it’s finally here for us to tinker with it.

E-paper is notorious for having very low refresh rates when compared to more conventional screens, much more so when driven in this method, but there are ways to speed them up a bit. Nevertheless, even when used as designed, they’re perfectly suited for being used in clocks which are easy on the eyes without a glaring backlight.

[Thanks Steveww for the tip!]

Coronavirus And Folding@Home; More On How Your Computer Helps Medical Research

March 22, 2020 by 56 Comments

On Wednesday morning we asked the Hackaday community to donate their extra computer cycles for Coronavirus research. On Thursday morning the number of people contributing to Team Hackaday had doubled, and on Friday it had doubled again. Thank you for putting those computers to work in pursuit of drug therapies for COVID-19.

I’m writing today for two reasons, we want to keep up this trend, and also answer some of the most common questions out there. Folding@Home (FAH) is an initiative that simulates proteins associated with several diseases, searching for indicators that will help medical researchers identify treatments. These are complex problems and your efforts right now are incredibly important to finding treatments faster. FAH loads the research pipeline, generating a data set that researchers can then follow in every step of the process, from identifying which chemical compounds may be effective and how to deliver them, to testing they hypothesis and moving toward human trials.

Continue reading “Coronavirus And Folding@Home; More On How Your Computer Helps Medical Research” →

Motorized LEGO Train Gets Qi Charging In The Track

March 22, 2020 by 6 Comments

This project started, as many do, with a simple idea. [Ben Hoad] just wanted to take a static LEGO Hogwarts Express train kit and make it motorized. It was compatible with standard LEGO track pieces, so all he should have to do was figure out how to shoehorn a motor in there and be done with it. Right?

Well, you already know how things like this go. It started with adding the motor, which ended up being relatively straightforward once [Ben] used some community LEGO CAD tools to figure out which kits had the specific parts he needed to redesign the train in such a way that he’d have enough space inside for the motor without ruining the way it looked. But then the feature creep kicked in, and he found himself falling down that familiar rabbit hole.

A 3D representation of the train’s internal components.

The first problem was how to reliably power the train. It turns out the rear car was more or less empty already, so that became home for two 18650 batteries (the project details say “16850” but we believe that is merely a typo). [Ben] didn’t want to have to take the thing apart every time it ran down, so he wondered if it would be possible to add wireless charging.

A Qi coil in the bottom of the train car and one in a specially designed section of track got the power flowing, but getting them lined up proved a bit finicky. So he added a Hall effect sensor to the car and a strong magnet to the track, so the train would know when the coils were lined up and automatically pump the brakes.

So now he had a motorized train that could recharge itself, but how should he turn it on and off? Well, with an ESP8266 along for the ride, he figured it would be easy to add WiFi control. With a bit of code and the Homebridge project, he was able to get the train to appear as a smart switch to Apple’s HomeKit. That allows him to start and stop the train from his smartphone, complete with a routine that returns the train to the charging station once it’s finished making the rounds. [Ben] says the next steps are to put some sanity checks in, such as shutting the motors down if the train hasn’t passed the charging station in a few minutes; a sure sign that it’s not actually moving.

All [Ben] needs to do now is implement automatic LEGO train decoupling before the plastic Hogwarts students come back from spring break.

Bee Counter Will Have You Up To Your Nectar In Hive Data

March 22, 2020 by 14 Comments

While we admit that free honey sounds pretty good, beekeeping is not some set-it-and-forget-it hobby where you can just put bees in a box and come back in a month to collect the goods. With the world’s bee population in decline, it’s more important than ever to monitor the health of hives.

One way to do that is to count the bees as they leave and reenter the hive. You can use the data to determine how many workers are working, or to compare activity between multiple hives. If you notice the bees are gone for longer and longer periods, it’s probably because their nearby nectar sources are dwindling and they have to travel farther to find flowers.

This open-source bee counter built by [hydronics2] is designed to fit the opening of a standard hive. The bees can only buzz themselves back in by flying through one of 24 little IR break-beam gates. Our favorite thing about this build is the way [hydronics2] created the individual gates by sandwiching two boards together with headers as spacers. It’s such a simple and perfect solution.

It’s also pretty cool that the board is designed to be compatible with any Feather or ItsyBitsy board, so there are a lot of options for data handling. Check out the brief demo we planted after the break, and stick around for the build video. If you’d prefer a more hands-off approach, try computer vision.

Continue reading “Bee Counter Will Have You Up To Your Nectar In Hive Data” →

High Power LoRa And Tropospheric Reflection Experiments

March 21, 2020 by 29 Comments

We’re used to LoRa as a free-to-use digital radio protocol allowing not-very-high data rate communications over distances of a few miles. It’s made all kinds of distributed sensor systems a breeze, and some experimenters have made an art of achieving communication over hundreds of miles. But what would happen if you took a brute-force approach to LoRa and simply wound up the power?

In a bid to test its efficiency at bouncing off the troposphere in normal conditions, [Inductive Twig] hooked up a HamShield 70cm LoRa shield to an 80W power amplifier and a high-gain Yagi antenna pointing directly upwards mounted with ingenuity on a spade, and drove around looking at the received result. With an effective radiated power of 1500W this wasn’t your normal LoRa, instead being operated with LoRa as an amateur radio mode.

For those not familiar with radio propagation, radio waves bounce off some surprising things. In this case the aim was to bounce them off the troposphere, but while radio amateurs and LoRa distance chasers wait until weather conditions deliver a so-called “lift” in which the troposphere is especially reflective, here the experiment was performed under normal flat conditions. The result characterizes LoRa’s possibilities for everyday extreme-range mode rather than chasing records, and in that there were some interesting results. The reflected signal was receivable in bursts with low but consistent signal strength, with the limiting factor during the test as that they ran out of land upon which to drive in the southernmost peninsula of New Jersey. We’ve heard of War-Driving for open WiFi… does this car dashboard setup count as LoRa-Driving?

LoRa is designed as a protocol tolerant of low signal levels and some packet loss, so this experiment is an interesting demonstration of its possibilities when used at higher powers under a licensed transmission. It shouldn’t be possible to use the 70cm band for reliable tropospheric propagation under non-lift conditions, but this shows that it can be done. Meanwhile, take a look at a previous attempt to push LoRa using a balloon.

How Constant Is Your Choice Of Lights?

March 21, 2020 by 19 Comments

The move from incandescent filament lamps to fluorescent, and then LED lighting over the last couple of decades has delivered immense benefits in terms of energy saving, but had brought with it problems for people sensitive to flicker or to too much of a particular set of wavelengths. It’s not always easy to quantify the propensity of a particular light for flickering. So [kk99] has produced an instrument returning a visual indication of its quality.

At its heart is an M5Stick ESP32 development platform, and a TSL250R light sensor hooked up to one of the ESP’s internal ADCs. The flicker waveform is displayed on the screen as a simple oscillograph, and a Fourier transform is performed to extract its frequency. The result is an extremely accessible and compact instrument, showing the suitability of the M5Stick form factor for such designs. So far we’ve only brought you an M5Stick in a password keeper, but we look forward to seeing more projects featuring it.

You can see the light flicker meter in action in the video below the break.

Continue reading “How Constant Is Your Choice Of Lights?” →

Screwy Math For Super Fine Adjustments: Differential Screws

March 21, 2020 by 38 Comments

For any sort of precision machine, precision adjustability is required. For the hacker this usually involves an adjustment screw, where the accuracy is determined by the thread pitch. This was not good enough for [Mark Rehorst] who wanted adjustment down to 10 μm for his 3D printer’s optical end-stop, so he made himself a differential adjustment screw.

Tiny adjustment can be made to the green block due to the thread pitch differences

Differential screws work by having two threads with a slightly different pitch on the same shaft. A nut on each section of thread is prevented from rotating in relation to the other, and when the screw is turned their relative position will change only as much as the difference between the two thread pitches.

The differential screw in this case started life as a normal M5 bolt with a 0.8 mm thread pitch. [Mark] machined and threaded section of the bolt down to a M4 x 0.7 mm thread. This means he can get 0.1 mm (100 μm) of adjustment per full rotation. By turning the bolt 1/10 rotation, the  relative movement comes down to 10 μm.

This mechanism is not new, originating from at least 1817. If you need fine adjustments on a budget, it’s a very elegant way to achieve it and you don’t even need a lathe to make your own. You can partially drill and tap a coupling nut, or make a 3D printed adapter to connect two bolts.

Fabricating precision tools on a budget is challenging but not impossible. We’ve seen some interesting graphite air bearings, as well as a 3D printed microscope with a precision adjustable stage.