There are more free 3D models online than one can shake a stick at, but what about paid models? Hosting models somewhere and putting a buy button in front of the download is certainly a solved problem, but after spending some time buying and printing a variety of non-free 3D models online, it’s clear that there are shortcomings in the current system.
What the problems are and how to address them depends a little on the different ways models get sold, but one thing is clear: poorly-designed 3D models are bad for consumers, and bad for the future of pay-to-download in general. Continue reading “3D Printering: The World Of Non-Free 3D Models Is Buyer Beware”
Working with graphics on microcontrollers has always meant focusing on making the most of limited resources. Particularly in the 8-bit era, all manner of tricks were used to get low-performance chips to achieve feats beyond their lowly station. However, these days, we’re blessed with 32-bit workhorses with clock speeds in the tens, or even hundreds, of MHz and many kilobytes of RAM to match. It’s these higher performance chips [Larry] had in mind when writing his JPEGDEC library.
As [Larry] discusses in a blog post on the topic, JPEG libraries already exist for the Arduino platform. However, many of these are aimed at 8-bit platforms with tiny amounts of RAM. While it’s possible to decode JPEGs piece by piece with some intelligent code under these conditions, it’s possible to go much faster when you’ve got a little more headroom. [Larry] does a great job of explaining the variety of optimizations he’s developed in the two decades since writing his first JPEG decoder back in 1994. From eliminating unnecessary marker checks to ignoring unneeded data for scaled-down output, it all adds up to get the job done faster. The library targets the Cortex-M0+, or any chip with a minimum of 20K of RAM, as its bare minimum to operate. Faster chips with higher clock rates naturally do better, and [Larry] provides benchmark decoding times for various common hardware using the library.
We’ve featured [Larry]’s GIF decoder for the Arduino platform before, again a useful library that’s optimised for good performance. If you’ve got your own neat tricks for image processing on microcontrollers, you know how to call!
In the 60s a musical recording technique called the “wall of sound” came to prominence which allowed artists to create complex layers of music resulting in a novel, rich orchestral feeling. While this technique resulted in some landmark albums (Pet Sounds by the Beach Boys for example) it took entire recording studios and many musicians to produce. This guitar, on the other hand, needs only a single musician but can create impressive walls of sound on its own thanks to some clever engineering.
Called the Circle Guitar and created by [Anthony Dickens], the novel instrument features a constantly-rotating wheel around the guitar’s pickups in the body. Various picks can be attached in different ways to the wheel which pluck the strings from behind continuously. This exceeds what a normal guitar player would be able to do on their own, but the guitarist is able to control the sounds by using several switches and pushbuttons which control a hexaphonic humbucker and are able to mute individual strings at will. Of course, this being the 21st century, it also makes extensive use of MIDI and [Anthony] even mentions the use of a Teensy.
While details on this project are admittedly a little fleeting, the videos linked below are well worth a watch for the interesting sounds this guitar is able to produce. Perhaps paired with a classic-sounding guitar amplifier it could produce other impressive walls of sound as well. Either way, we could expect someone like [Brian Wilson] to be interested in one once it is in production.
Thanks to [Mel] for the tip!
Continue reading “Circle Guitar Creates Wall Of Sound”