DIY Arduino Hearing Test Device

October 23, 2022 by Dave Walker 18 Comments

Hearing loss is a common problem for many – especially those who may have attended too many loud concerts in their youth. [mircemk] had recently been for a hearing test, and noticed that the procedure was actually quite straightforward. Armed with this knowledge, he decided to build his own test system and document it for others to use.

audiogram showing the results of the arduino hearing test device — Resultant audiogram from the device showing each ear in a different color

By using an Arduino to produce tones of various stepped frequencies, and gradually increasing the volume until the test subject can detect the tone, it is possible to plot an audiogram of hearing threshold sensitivity. Testing each ear individually allows a comparison between one side and the other.

[mircemk] has built a nice miniature cabinet that holds an 8×8 matrix of WS2812 addressable RGB LEDs. A 128×64 pixel OLED display provides user instructions, and a rotary encoder with push-button serves as the user input.

Of course, this is not a calibrated professional piece of test equipment, and a lot will depend on the quality of the earpiece used. However, as a way to check for gross hearing issues, and as an interesting experiment, it holds a lot of promise.

There is even an extension, including a Class D audio amplifier, that allows the use of bone-conduction earpieces to help narrow down the cause of hearing loss further.

There’s some more information on bone conduction here, and we’ve covered an intriguing optical stimulation cochlear implant, too.

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Kodak Film Factory Revealed

October 18, 2022 by Dave Walker 51 Comments

Anybody born before the mid 1990s will likely remember film cameras being used to document their early years. Although the convenience of digital cameras took over and were then themselves largely usurped by mobile phones, there is still a surprising variety of photographic film being produced. Despite the long pedigree, how many of us really know what goes into making what is a surprisingly complex and exacting product? [Destin] from SmarterEveryDay has been to Rochester, NY to find out for himself and you can see the second in a series of three hour-long videos shedding light on what is normally the strictly lights-out operation of film-coating.

Kodak first digital camera 1975 — Kodak’s first attempt at a digital camera in 1975. The form-factor still left something to be desired…

Kodak have been around in one form or another since 1888, and have been producing photographic film since 1889. Around the turn of the Millennium, it looked as though digital photography (which Kodak invented but failed to significantly capitalize on) would kill off film for good, and in 2012 Kodak even went into Chapter 11 bankruptcy, which gave it time to reorganize the business.

They dramatically downsized their film production to meet what they considered to be the future demand, but in a twist of fortunes, sales have surged in the last five years after a long decline. So much so, in fact, that Kodak have gradually grown from running a single shift five days per week a few years ago, to a 24/7 operation now. They recently hired 300 Film Technicians and are still recruiting for more, to meet the double-digit annual growth in demand.

[Destin] goes to great lengths to explain the process, including making a 3D model of the film factory, to better visualize the facility, and lots of helpful animations. The sheer number of steps is mind-boggling, especially when you consider the precision required at every step and the fact that the factory runs continuously… in the dark, and is around a mile-long from start to finish. It’s astonishing to think that this process (albeit at much lower volumes, and with many fewer layers) was originally developed before the Wright Brothers’ first powered flight.

We recently covered getting a vintage film scanner to work with Windows 11, and a little while back we showed you the incredible technology used to develop, scan and transmit film images from space in the 1960s.

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Arduino Lo-Fi Orchestra closeup thumbnail

Lo-Fi Orchestra Learns Tubular Bells

October 14, 2022 by Dave Walker 4 Comments

Hardware projects often fall into three categories: Those that flash lights, those that make sounds and those that move. This virtuoso performance by [Kevin]’s “Lo-Fi Orchestra” manages all three, whilst doing an excellent job of reproducing the 1973 musical classic Tubular Bells by Mike Oldfield.

Producing decent polyphonic sounds of different timbres simultaneously is a challenge for simple microcontroller boards like Arduinos, so [Kevin] has embraced the “More is more” philosophy and split up the job of sound generation in much the same way as a traditional orchestra might. Altogether, 11 Arduino Nanos, 6 Arduino Unos, an Arduino Pro Mini, an Adafruit Feather 32u4, and a Raspberry Pi running MT32-Pi make up this electronic ensemble.

Arduino servo drumkit — Arduino Servo & Relay Drumkit

The servo & relay drumkit is a particular highlight, providing some physical sounds to go along with the otherwise solid-state generation.

The whole project is “conducted” over MIDI and the flashing sequencer in the middle gives a visual indication of the music that is almost hypnotic. The performance is split into two videos (after the break), and will be familiar to fans of 70’s music and classic horror movies alike. We’re astonished how accurately [Kevin] has captured the mood of the original recording.

If this all looks slightly familiar, it may be because we have covered the Lo-Fi Orchestra before, when it entertained us with a rousing rendition of Gustav Holst’s Planets Suite. If you’re more interested in real Tubular Bells than synthesized ones, then check out this MIDI-controlled set from 2013. Continue reading “Lo-Fi Orchestra Learns Tubular Bells“ →

DIy Arduino FM radio enclosure with the lid off, showing the electronics inside

DIY Arduino Due TEA5767 FM Radio

October 8, 2022 by Dave Walker 10 Comments

Older hackers will remember that a crystal set radio receiver was often one of the first projects attempted. Times have changed, but there’s still something magical about gathering invisible signals from the air and listening to the radio on a homemade receiver. [mircemk] has brought the idea right up to date by building an FM radio with an OLED display, controlled with a rotary encoder.

The design is fairly straightforward, based as it is on another project that [mircemk] found on another site, but the build looks very slick and would take pride of place on any hacker’s workbench. An Arduino Due forms the heart of the project, controlling a TEA5767 module, an SH1106 128×64 pixel OLED display and a rotary encoder. The sound signal is passed through an LM4811 headphone amplifier for private listening, and a PAM8403 Class D audio amplifier for the built-in loudspeaker. The enclosure is made from PVC panels, and accented with colored adhesive tape for style.

It’s easier than ever before to quickly put together projects like this by connecting pre-built modules and downloading code from the Internet, but that doesn’t mean it’s not a worthwhile way to improve your skills and make some useful devices like this one. There are so many resources available to us these days and standing on the shoulders of giants has always been a great way to see farther.

We’ve shown some other radio projects using Arduinos and the TEA5767 IC in the past, such as this one on a tidy custom PCB, and this one built into an old radio case.

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close-up image of a philodendron houseplant with electrodes attached, connected to a robot arm holding a machete

(Mostly) Harmless Houseplant Wields Machete

October 6, 2022 by Dave Walker 27 Comments

In a straight fight between a houseplant and a human, you might expect the plant to be at a significant disadvantage. So [David Bowen] has decided to even the odds a little by arming this philodendron with a robot arm and a machete.

The build is a little short on details but, from the video, it appears that adhesive electrodes have been attached to the leaves of the recently-empowered plant and connected directly to analog inputs of an Arduino Uno. From there, the text tells us that the signals are mapped to movements of the industrial robot arm that holds the blade.

It’s not clear if the choice of plant is significant, but an unarmed philodendron appears to be otherwise largely innocuous, unless you happen to be a hungry rodent. We hope that there is also a means of disconnecting the power remotely, else this art installation could defend itself indefinitely! (or until it gets thirsty, at least.) We at Hackaday welcome our new leafy overlords.

We have covered the capabilities of plants before, and they can represent a rich seam of research for the home hacker. They can tell you when they’re thirsty, but can they bend light to their will? We even held a Plant Communication Hack Chat in 2021.

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Arduino IDE v2.0 screen with callout tags to identify features

Arduino IDE 2.0 Is Here

September 28, 2022 by Dave Walker 84 Comments

Arduino have released the latest version of their Integrated Development Environment (IDE), Version 2.0 and it is a big step up from the previous release, boasting plenty of new features to help you to develop your code more easily.

As the de-facto way for beginners to get into programming hardware, more experienced users have sometimes complained about what they see as the over-simplistic IDE — even lacking relatively basic features such as autocomplete. The new version provides this, and much more besides. Continue reading “Arduino IDE 2.0 Is Here” →

£D printed parts with glossy toner transfer images on

Add Full-Color Images To Your 3D Prints With Toner Transfer

September 27, 2022 by Dave Walker 43 Comments

Toner transfer is a commonly-used technique for applying text and images to flat surfaces such as PCBs, but anybody who has considered using the same method on 3D prints will have realized that the heat from the iron would be a problem. [Coverton] has a solution that literally turns the concept on its head, by 3D printing directly onto the transparency sheet.

instrument panel design with toner transfer markings — The fine detail is great for intuitive front-panel designs

The method is remarkably straightforward, and could represent a game-changer for hobbyists trying to achieve professional-looking full-color images on their prints.

First, the mirrored image is printed onto a piece of transparency film with a laser printer. Then, once the 3D printer has laid down the first layer of the object, you align the transparency over it and tape it down so it doesn’t move around. The plastic that’s been deposited already is then removed, and a little water is placed on the center of the bed. Using a paper towel, the transparency gets smoothed out until the bubbles are pushed off to the edges.

Another few pieces of tape hold the transparency down on all corners, and the hotend height is adjusted to take into account the transparency thickness. From there, the print can continue on as normal. When finished, the image should be fused with the plastic. If it’s hard to visualize, check out the video after the break for a step-by-step guide.

There are, of course, some caveats. Aligning the transfer and the print looks a little fiddly at the moment, the transparency material used (obviously) has to be rated for use in laser printers, and it only works on flat surfaces. But on the other hand, there will be some readers who already have everything they need to try this out at home right now — and we’d love to see the results!

We’ve covered some other ways to get color and images onto 3D prints in the past, such as this hydrographic technique or by using an inkjet printhead, but [Coverton]’s idea looks much simpler than either of those. If you’re interested in toner transfer for less heat-sensitive materials, then check out this guide from a few years back, or see what other Hackaday readers have been doing on wood or brass.

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