Year: 2021

Free To Good Home: FPGA Supercharged Audio/Video Synthesizer

March 3, 2021 by 10 Comments

Audio and video synthesizers have been around for decades, and are pretty much only limited by one’s willingness to spend money on them.  That is, unless you can develop your own FPGA-supercharged synthesizer to really get a leg up on the consumer-grade components. Of course, as [Julian] found out in this four-year project, you tend to pay for it anyway in time spent working on your projects.

[Julian] has actually decided to stop working on the project and open-source it to anyone who wants to continue on. He has already finished the PCB layout on a gargantuan 8-layer print, done all of the routing and parts selection, and really only needed to finish testing it to complete the project. It’s powered by the Xilinx Zynq and is packed with features too: HDMI, DDR3 ram, USB, a handful of sensors, and an Arduino Uno-style header to make interfacing and programming a breeze.

While we’re sympathetic with setting aside a project that we’ve worked so hard on, with most of the work done on this one it should be pretty easy to pick up and adapt for anyone interested in carrying the torch. If you were hoping to wet your whistle with something with fewer PCB layers, though, we’ve seen some interesting (but slightly simpler) video synthesizers made out of other unique hardware as well.

 

The 70s Are Calling To Shed Some Light

March 2, 2021 by 24 Comments

Remember when phones didn’t all look the same? We had a good thing going in the early cell phone days, which seemed like a brief holdover from the Western Electric (et. al) era where you could get a phone that suited your inner minimalist or princess, and choose the color to boot.

[Dubchinsky] found a beautiful phone from this bygone era and saved it from one of two likely fates — the landfill, or else a life languishing as a piece of vintage technology that’s just sitting around for looks. Instead, this phone found a second calling as a lovely desk lamp with secret goose neck flexibility. The lamp itself is an inexpensive LED module from ebay that’s wired up to mains power through a push button switch in the phone’s base.

We absolutely love that [Dubchinsky] wrapped the curly cord around the goose neck, but were a bit disappointed that he didn’t use the hook switch to turn the lamp on and off. In the comments, he says that the plastic felt like it was too brittle to stand up to repeated actuation of such a heavy switch. That’s understandable. [Dubchinsky] also thought about using the rotary dial as a dimmer, and we think that’s a bright idea.

Between the guide, the pictures, and the build process video after the break, this is pretty much a complete how-to. We think that is commendable given that [Dubchinsky] is selling these lamps on etsy.

Do ya miss spinning the rotary dial and long for somewhat simpler days? Hook your finger into this rotary cell phone.

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Circuit Impedance Calculations Without Cumbersome Simulations

March 2, 2021 by 11 Comments

Using circuit simulating software like SPICE can be a powerful tool for modeling the behavior of a circuit in the real world. On the other hand, it’s not always necessary to have all of the features of SPICE available all the time, and these programs tend to be quite expensive as well. To that end, [Wes Hileman] noticed an opportunity for a specific, quick method for performing impedance calculations using python without bulky, expensive software and came up with a program which he calls fastZ.

The software works on any network of passive components (resistors, capacitors, and inductors) and the user can specify parallel and series connections using special operators. Not only can the program calculate the combined impedance but it can perform frequency analysis at a specified frequency or graph the frequency response over a wide range of frequencies. It’s also running in python which makes it as simple as importing any other python package, and is also easy to implement in any other python program compared to building a simulation and hoping for the best.

If you find yourself regularly drawing Bode plots or trying to cobble together a circuit simulation to work with your python code, this sort of solution is a great way to save a lot of headache. It is possible to get the a piece of software like SPICE to to work together with other python programs though, often with some pretty interesting results.

Cycling Cadence Display With ESP32

March 2, 2021 by 9 Comments

Terry Pratchett once said “Wisdom comes from experience. Experience is often a result of lack of wisdom.” This is as true with technical skills as it is with the rest of life, and you won’t truly understand a specific topic unless you’ve struggled with it a bit. [publidave] wanted a simple wireless display for a bluetooth cycling cadence sensor, and soon found himself deep down the rabbit hole of Micropython and Bluetooth Low Energy on the ESP32.

[publidave] had converted his bicycle for indoor training during lockdown and winter, and realized he can’t use the guided training app and view his cadence simultaneously, so he needed a dedicated cadence display. Since [publidave] was comfortable with Python, he decided to give Micropython on the ESP32 ago. Bluetooth Low Energy can be rather confusing if you haven’t implemented it before, especially if good examples are hard to come by. In short, the ESP32 needs to find the sensor, connect to it, select the right service, and listen for the notifications containing the data. The data is then converted to RPM and displayed on a small OLED display. [publidave] does an excellent job of describing what exactly he did, highlighting the problems he encountered, and how he solved them.

In the end, he had a functional display, a good idea of what he would do differently next time, and a lot of additional knowledge and understanding. In our book that’s a successful project.

Since so much of the health related devices work with Bluetooth Low Energy, it could be handy to know the technology and how to interface with it. It would allow you to do things like unbrick a $2000 exercise bike,

3D-Printed Macro Pad Ditches The PCB With Slick Wiring Guides

March 2, 2021 by 15 Comments

Reddit user [duzitbetter] showed off their design for a 3D-printed programmable macro keyboard that offers a different take on what can be thought of as a sort of 3D-printed PCB. The design is called the Bloko 9 and uses the Raspberry Pi PICO and some Cherry MX-style switches, which are popular in DIY keyboards.

The enclosure and keycaps are all 3D printed, and what’s interesting is the way that the enclosure both holds the components in place as well as providing a kind of wire guide for all the electrical connections. The result is such that bare copper wire can be routed and soldered between leads in a layout that closely resembles the way a PCB would be routed. The pictures say it all, so take a look.

Bloko 9 is available as a paid model, and while going PCB-free thanks to 3D printing is a technique others have played with, it is very well demonstrated here and shows there is still plenty of room to innovate on the concept. DIY keyboard and macro pad design is also fertile ground for hackers; we have even seen that it’s possible to 3D print one right down to the switches themselves.

Wireless, Low Power E-Ink Weather Gadget

March 2, 2021 by 14 Comments

Not that long ago, making a low-power and wireless weather display complete with an e-ink screen would have required a lot of work and almost certainly would have been larger than the device [Dmitry] created.

(1) Weather alert indicator, (2) Current temperature, (3) Humidity and wind, (4) 24-hour temperature graph, (5) 24-hour precipitation probably graph

His low power e-ink weather gadget takes advantage of one of the niftier developer boards out there to create a useful and slim device that does exactly what he needs and not a lick more. It’s fast to look up weather online, but not as fast as glancing at a display in a convenient location.

The board [Dmitry] selected is a LilyGO TTGO T5s, an ESP32-based board that integrates an e-ink display, which requires no power unless being updated. It has been loaded with just enough smarts to fetch weather information using the OpenWeather API, and update the display accordingly.

Powering up the WiFi to fetch an easily-parsed JSON file and update the display only once per hour means that a battery can provide months of runtime. As a bonus, the LilyGO board even includes the ability to charge the battery, making things awfully convenient.

The bill of materials is here and code for the device, including setup directions, is on the project’s GitHub repository. And if your tastes happen to run more towards the artistic than utilitarian, we have just the weather display for you.

Rube Goldberg’s Least Complicated Invention Was His Cartooning Career

March 2, 2021 by 27 Comments

The name Rube Goldberg has long been synonymous with any overly-built contraption played for laughs that solves a simple problem through complicated means. But it might surprise you to learn that the man himself was not an engineer or inventor by trade — at least, not for long. Rube’s father was adamant that he become an engineer and so he got himself an engineering degree and a job with the city. Rube lasted six months engineering San Francisco’s sewer systems before quitting to pursue his true passion: cartooning.

Rube’s most famous cartoons — the contraptions that quickly became his legacy — were a tongue-in-cheek critique meant to satirize the tendency of technology to complicate our lives in its quest to simplify them. Interestingly, a few other countries have their own version of Rube Goldberg. In the UK it’s Heath Robinson, and in Denmark it’s Robert Storm Petersen, aka Storm P.

Rube Goldberg was a living legend who loved to poke fun at everything happening in the world around him. He became a household name early in his cartooning career, and was soon famous enough to endorse everything from cough drops to cigarettes. By 1931, Rube’s name was in the Merriam-Webster dictionary, his legacy forever cemented as the inventor of complicated machinery designed to perform simple tasks. As one historian put it, Rube’s influence on culture is hard to overstate.

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