Magic Record Stand Can Play Your Records For You

Vinyl remains a popular format, despite taking a huge hit in popularity for a couple decades while CDs ruled the roost. It has a charm that keeps it relevant, and likely will continue to do so until everyone who grew up with a record player dies out. In the meantime, [sp_cecamp] has come up with a great way to experience your collection, with the magic of modern technology. It goes by the name of Plynth.

Fundamentally, it’s a small record stand with an excellent party trick. The prototype consists of a 3D-printed body, which holds a record sleeve at an attractive angle for display. A camera built into the base then images the artwork. The first image taken is run through the Google Vision API, and further images are then run through OpenCV to identify the record. This data is then passed to the Spotify API to play the track. The whole process takes a couple of seconds, and the music is then pumped out of whatever streaming device is connected to the rig.

It’s a fun way to play your old records, and would be a welcome change to those tired of screaming at Siri to play Weezer (Blue Album), not Weezer (Green Album). For those interested, [sp_cecamp] has thrown up a site to gauge interest in the project, and may make a limited production run in future.

Of course, you could instead just go about building your own turntable. To each their own!

Mechanical Tremolo Does Things The Old-School Way

The word “tremolo” has a wide variety of meanings in the musical lexicon. A tremolo effect, in the guitar community at least, refers to a periodic variation in amplitude. This is often achieved with solid state electronics, but also recalls the sounds created by Hammond organs of years past with their rotating Leslie speakers. [HackaweekTV] decided to do things the old fashioned way, building a mechanical tremolo effect of his own (Youtube link, embedded below).

Electronically, the signal is simply passed through a linear audio potentiometer. The effect is generated by rapidly cycling this potentiometer up and down. The motion is achieved through a geared motor salvaged from a Roomba, which turns a cam. A sprung follower sits on top of the cam, and is attached to the potentiometer.

There were some challenges in development. Rigidity of the frame was an issue, and the follower had issues with snagging on the cam. However, with some careful iteration they were able to get everything up and running. The final project sounds great, and with the amplifier turned up, there’s no need to worry about the sound of the moving parts.

Naturally, you can always build a tremolo with a 555 instead. Video after the break.

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Reverse Engineering WyzeSense Hardware

Wyze are a company that produces a variety of home automation products. Their Wyze Sense package is a system of contact and PIR home security sensors, that piggy backs off their Wyze Cam product. In the interests of being able to use this hardware outside the prescribed corporate ecosystem, [Xuan Xing] got down to hacking.

The project starts by tearing down the Wyze Cam, and getting serial console access. This was made easier by an existing Github project, which develops custom firmwares for smart cameras. With that in place he was able to see what was going on under the hood, and read the camera’s system logs.

By poring over these logs, and examining the disassembled Wyze Sense dongle, he’s well on the way to discovering how the sensors communicate with the Wyze Cam. The end goal is to enable the Wyze security sensors to be used with the Raspberry Pi platform, and to share the code on Github for other makers to experiment with.

Home automation platforms come and go quicker than the seasons change. This makes the hardware a popular target for hackers trying to get things running independently of any one company’s servers.

Injection Molding With A Hot Glue Gun

Injection molding is an industrial process used the world over for the quick and economical production of plastic parts. [Nikodem Bartnik] wanted to experiment with this at home, so whipped up some molds and got to work (Youtube link, embedded below).

[Nikodem] produced aluminium molds, using a Dremel-based CNC platform. This allowed for the design to be created in CAD software, and helps with the production of the geometry for both the part, as well as the gates and vents. Having learned about thermal issues with an early attempt, the mold was then clamped in a vice. Wood was used as an insulator to minimise heat lost to the vice.

With this setup, it was possible to mold M5 washers using hot glue, with good surface finish. Later attempts with a larger mold were unsuccessful, due to the glue cooling off before making it through the entire mold. [Nikodem] has resolved to improve his setup, and we look forward to seeing what happens next. We’ve seen others experiment in this area before, too. Video after the break.

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Google Home Mini Gets A Headphone Jack

The Google Home Mini can be a useful home assistant device. It can set reminders, tell you the weather, and even play you music. [Brian] had a few lying around, and decided he wanted to hook one up to a beefier set of speakers. Thus, he installed a headphone jack into the Google Home Mini.

The quick and dirty approach to such a task is to solder a jack to the speaker connections. However, this is an amplified signal, rather than a line level signal suitable for feeding to an amplifier. It’s also mono only. The Google Home Mini uses the TAS5720L mono digital amplifier chip, and some investigation with a logic analyzer and a datasheet allowed [Brian] to figure out the format of the I2C digital audio signal.

With this knowledge in hand, [Brian] hacked in a PCM5102A digital amplifier chip to the Google Home Mini. It can accept audio data in the same format as the TAS5720L, and is readily available on eBay for use with the Raspberry Pi and other maker platforms. With a 3D printed baseplate and some careful soldering, [Brian] was able to integrate the stereo amplifier and a headphone jack neatly into the Google Home.

Unfortunately, the audio output is only two mono channels rather than true stereo, as the device outputs the same data on both left and right  channels in the I2C data. Regardless, the hack works, and [Brian] now has a high-quality voice assistant that he can hook up to a decent pair of speakers.

 

 

Adding Bluetooth Control To A Benchtop Power Supply

In 2019, it’s possible to kit out a lab with all the essentials at an even cheaper price than it has ever been. The DPS3005 is one such example of low-cost equipment – a variable power supply available for less than $50 with a good set of features. [Markel Robregado] wanted a little more functionality, however, and got down to work.

The crux of [Markel]’s project is improved connectivity. A Texas Instruments CC2640R2F Launchpad is employed to run the show, with its Bluetooth Low Energy capability coming in handy. A custom smartphone app communicates with the Launchpad, which then communicates with the power supply over its Serial Modbus interface. Through the app, [Markel] can set the voltage and current limit on the power supply, as well as switch it on and off. This could prove useful, particularly for remote triggering in the case of working with dangerous projects. Sometimes it pays to take cover, after all.

We’ve seen power supplies modified before; this pot mod for higher precision is a particular treat. If you’ve hacked your bench hardware for better performance, let us know. Video after the break.

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Creating A Laser Cutter From A 3D Printer

The average FDM 3D printer is not so different from your garden variety laser cutter. They’re often both Cartesian-coordinate based machines, but with different numbers of axes and mounting different tools. As [Gosse Adema] shows, turning a 3D printer into a laser cutter can actually be a remarkably easy job.

The build starts with an Anet A8 3D printer. It’s an affordable model at the lower end of the FDM printer market, making it accessible to a broad range of makers. With the help of some 3D printed brackets, it’s possible to replace the extruder assembly with a laser instead, allowing the device to cut and engrave various materials.

[Gosse] went with a 5500 mW diode laser, which allows for the cutting and engraving of wood, some plastics and even fabrics. Unlike a dedicated laser cutter there are no safety interlocks and no enclosure, so it’s important to wear goggles when the device is operating. Some tinkering with G-Code is required to get things up and running, but it’s a small price to pay to get a laser cutter on your workbench.

We’ve seen [Gosse]’s 3D printer experiments before, with the Anet A8 serving well as a PCB milling machine.