A Mobile Phone From 1985

May 25, 2023 by Bryan Cockfield 7 Comments

It might seem quaint through the lends of history we have the luxury of looking through, but in the mid 1980s it was a major symbol of status to be able to communicate on-the-go. Car phones and pagers were cutting-edge devices of the time, and even though there were some mobile cellular telephones, they were behemoths compared to anything we would recognize as a cell phone today. It wasn’t until 1985 that a cell phone was able to fit in a pocket, and that first device wasn’t just revolutionary because of its size. It made a number of technological advancements that were extremely impressive for its time, and [Janus Cycle] takes us through some of those in this teardown video.

The Technophone came to us from Great Britain by way of a former Ericsson engineer named Nils Mårtensson. It was able to achieve its relatively small stature using a surface-mount PCB, which was a cutting-edge manufacturing process for the time. Not only did it use surface-mount components and boards, but the PCB itself has 12 layers and two sides and hosts two custom Technophone chips. The phone is relatively modular as well, with the screen, battery pack, and other components capable of easily disconnecting from the main board. Continue reading “A Mobile Phone From 1985” →

Inside A Pair Of Smart Sunglasses

May 6, 2023 by Bryan Cockfield 14 Comments

If you’re willing to spend $200 USD on nothing more than 100 grams of plastic, there are a few trendy sunglasses brands that are ready to take your money before you have time to think twice. Sure, you can get a pair of sunglasses for an order of magnitude less money that do the exact same job, but the real value is in the brand stamped into the plastic and not necessarily the sunglasses themselves. Not so with this pair of Ray-Bans, though. Unlike most of their offerings, these contain a little bit more than a few bits of stylish plastic and [Becky Stern] is here to show us what’s hidden inside.

At first glance, the glasses don’t seem to be anything other than a normal pair of sunglasses, if a bit bulky But on closer inspection they hide a pair of cameras and a few other bits of electronics similar to the Google Glass, but much more subtle. The teardown demonstrates that these are not intended to be user-repairable devices, and might not be repairable at all, as even removing the hinges broke the flexible PCBs behind them. A rotary tool was needed to remove the circuit boards from the ear pieces, and a bench vice to remove the camera modules from the front frame. We can presume these glasses will not be put back together after this process.

Hidden away inside is a pair of cameras, a Snapdragon quad-core processor, capacitive touch sensors, an amplifier for a set of speakers. Mostly this is to support the recording of video and playback of audio, and not any sort of augmented reality system like Google Glass attempted to create. There are some concerning ties with Facebook associated with this product as well which will be a red flag for plenty of us around here, but besides the privacy issues, lack of repairability, and lack of features, we’d describe it as marginally less useful as an entry-level smartwatch. Of course, Google Glass had its own set of privacy-related issues too, which we saw some clever projects solve in unique ways.

Continue reading “Inside A Pair Of Smart Sunglasses” →

Electric Skateboard Becomes Mobile Skate Park

March 30, 2023 by Bryan Cockfield 3 Comments

While building a skate park might not appear to have much in common with software development, at they very least, they both suffer from a familiar problem: scalability. Bigger skate parks need more ramps and features, and there’s no real way to scale up a construction project like this efficiently like you could with certain kinds of software other than simply building more features. This was something [Kirk] noticed, but was able to scale up a skate park in a way we’ve never thought of before. He built a mobile skateboard ramp that can turn any place into a skate park.

The mobile and approximately sidewalk-width platform is able to move around thanks to an electric skateboard as its foundation. It adds a NVIDIA Jetson Nano for control with a PS4 controller for input, although steering a skateboard with an actuator took a few prototypes to figure out since skateboards are designed to be steered by shifting the rider’s weight. Since they are already designed to carry a human-amount of weight, though, it was at least able to tote the ramp around with relative ease. Another problem was lowering the ramp into position when it got to the desired area, but with an electrically-controlled jack and a few rounds of debugging was eventually able to do this without much issue.

With all of that project development behind him, [Kirk] can finally realize his dream of having ramps scattered all across his neighborhood like in the classic videogame Paperboy, without needing to build them all individually or ask for permission to place them around his neighbor’s homes. For any future iterations of this build, we might consider adding tank tracks to the electric skateboard for better off-road performance, like facilitating a jump across a patch of grass.

Solar Cells As Art Form

August 31, 2022 by Bryan Cockfield 10 Comments

When most of us approach a project, we have a certain problem to solve. 3D printing, microcontrollers, batteries, and all kinds of technologies are usually tools to accomplish some task. This is not necessarily true in the art world, though, where the intrinsic nature of these tools can be explored for their own sake rather than as a means to an end. The latest one that came across our desk is this light-powered sound generator.

The art piece looks a bit like a mobile with rotating arms, holding various small solar cells each connected to a speaker. As the arms pivot, the light falling on the cells changes which drives a specially-designed circuit connected to a speaker. The circuit acts as an oscillator, passing the changing voltage from the cell through various capacitors and transistors to produce changing tones in the speaker.

The effect of the rotating solar panels is not only oscillations from the speakers as the light changes, but oscillations in the sound of the speakers as they rotate towards and away from the observer. It’s a unique project and perfect for the art show it was in. It’s also not the only sound-focused art installation we’ve ever seen before, be sure to check out this one based on an ESP32.

PERSEUS-9, The Dual-6502 Portable Machine That Should Have Been

July 29, 2022 by Dan Maloney 53 Comments

A question: does anyone who was around in the early days of the 8-bit computer revolution remember a dual-CPU 6502 portable machine like this one? Or just a dual-CPU machine? Or even just a reasonably portable computer? We don’t, but that begs a further question: if [Mitsuru Yamada] can build such a machine today with parts that were available in the era, why weren’t these a thing back then?

We’re not sure we have an answer to that question, but it just may be that nobody thought of it. Or, if they did, the idea of putting two expensive CPUs into a single machine was perhaps too exorbitant to take seriously. Regardless, the homemade mobile is another in a growing line of beautifully crafted machines in the PERSEUS line, all of which have a wonderfully similar look and feel.

For the PERSEUS-9, [Yamada-san] chose a weatherproof aluminum enclosure with just the right form-factor for a mobile computer, as well as a sturdy industrial look. Under the hood, there are two gorgeous wire-wrap boards, one of which is home to the 48-key keyboard and the 40×7 alphanumeric LED matrix display, while the other is a densely packed work of art holding the two 6502s and a host of other DIPs.

The machine is a combination of his PERSEUS-8 computer, his 6802 serial terminal, and the CI-2 floating point interpreter he built for the PERSEUS-8. A brief video of the assembly of this delightful machine is below. One of the many things about these builds that impress us is the precision with which the case is machined, apparently all by hand. How he managed to drill out all those holes for the keyboard without having one even slightly out of alignment without the aid of CNC is beyond us.

Continue reading “PERSEUS-9, The Dual-6502 Portable Machine That Should Have Been” →

Fail Of The Week: Flipped Cable Leads To Fried Radio

August 3, 2021 by Donald Papp 18 Comments

[Doug]’s newly-installed Yaesu FT-891 mobile transceiver failed to power up despite a careful installation, and it turns out to have ultimately been caused by a reversed cable. There’s a happy ending, however. Since the only real casualties were a blown resettable fuse and a badly-burned resistor that damaged the PCB, [Doug] was able to effect a repair. Things could have been worse, but they also could have been better. Damage could have been prevented entirely with some better design, which [Doug] explains during his analysis of what went wrong.

The destroyed SMT resistor and pads were easily replaced with a through-hole version, thanks to the schematics.

The main problem was that the generic RJ12 cable that [Doug] used to connect radio components had its connections reversed. This would not be a problem if it was used to connect a landline telephone to the wall, but it was a big problem when used to connect the radio components together. According to the radio schematics, the two center wires carry +13 V and GND, which meant that a reversed cable delivered power with reversed polarity; never an optimal outcome.

Once the reversed power arrived at the other end, [Doug] discovered something else. Diodes whose job would be to protect against reverse polarity were marked DO NOT INSTALL, probably to shave a few cents off the bill of materials. As a result, the full 13 V was soaked up by a 1/8 W surface mount resistor which smoldered and burned until a fuse eventually blew, but not before the resistor and pads were destroyed. Thankfully, things cleaned up well and after replacing the necessary parts and swapping for a correct cable, things powered up normally and the mobile radio was good to go.

Curious for a bit more details about mobile radio installations? Check out our own Dan Maloney’s rundown on installing a discontinued (but perfectly serviceable) Yaesu FT-8900R.

Mobile Sauna For On-The-Go Relaxation

July 30, 2021 by Bryan Cockfield 6 Comments

While it might be nice to imagine owning a cabin in the woods to escape from society, complete with an outdoor sauna to take in the scenic views of nature, most of us will be satisfied with the occasional vacation to a cabin like that. For those trips, or even for long-term camping trips, [Schitzu] and a group of friends thought it would be nice to be able to ensure access to a sauna. For that, they created this mobile, timber-framed sauna that he can tow behind his car.

The sauna is built out of a combination of spruce and Douglas fir, two types of lumber with weather-resistant properties. For an additional layer of protection, the frame was varnished after assembly. The walls are filled with baked cork for insulation, and heat is provided by a small wood-fired oven placed in the corner of the sauna with a stove pipe plumbed through the roof. Performance of the sauna shows good design too, as it can heat up quickly and performs well in all of the tests so far. The final touch on the mobile sauna was to finish the roof with some solar panels in order to gather some energy for long-term camping trips and also to ensure that the roof was protected from rain and weather.

The sauna is designed for two adults to sit in, but it will also accommodate a single person to lay down and sleep (presumably when not using it as a sauna), so the entire trailer actually makes a fairly capable mobile camper too. With the addition of a panoramic window, anyone can take in the sights as well as someone with their own permanently-located sauna could, which is a win in all of our books. If you’re looking for a mobile sauna that’s a little more discrete though, be sure to check out this one which is built in the back of a white panel van.