Why reach for a bland, commercially available calculator when you be using a model that employs RPN (Reverse Polish Notation) in its calculations and be a custom build all at the same time? The kids may have colour TFTs and graphing functions, but your keyboard has no equals sign, and that means something.
Unfortunately for RPN enthusiasts, the RPN calculator is a little on the rare side. Since classic models from the 1970s and ’80s are rather pricey, [Anton Poluektov]’s just build his own called the OpenCalc. This glorious specimen is an open hardware RPN calculator with more than a nod to the venerable Hewlett Packard HP42 in its design.
At its heart is an STM32L476 low-power ARM processor and a Sharp Memory LCD, all on a PCB clad in a 3D-printed case you’d have been proud to own in the 1980s. It runs from a CR2032 which is more than can be said for some modern styles of calculator, and it gives the user everything you could wish for in a scientific calculator. The key legends are a set of printable stickers, which when printed on self-adhesive laser film prove durable enough to last. All the resources can be found in a GitHub repository, so if RPN is your thing there’s nothing to stop you building one for yourself.
A lot of our projects make noise. It can be something as simple as a microcontroller driving a small speaker or a truly ambitious Hi-Fi project, but common to all of them is the desire to get that sound out in as audible and high-quality a manner as possible. We’ve been known to make fun of the more preposterous side of the Hi-Fi world at times, but behind it all there’s a basis of solid and provable audio engineering that can be brought to bear on almost any project involving sound and electronics. Perhaps it’s time to devote some time to a series exploring the topic, and what better place to start than the ultimate destination for all that sound. Any Hi-Fi is only as good as the ears of the person listening to it, so in out journey through the world of audio that’s where we’ll start. Continue reading “Know Audio: Start At The Very Beginning”→
Since the launch of the Raspberry Pi Pico back in January the little board with its newly-designed RP2040 microcontroller has really caught the imagination of makers everywhere, and we have seen an extremely impressive array of projects using it. So far the RP2040 has only been available on a ready-made PCB module, but we have news today direct from Eben Upton himself that with around 600k units already shipped, single-unit sales of the chip are commencing via the network of Raspberry Pi Approved Resellers.
This news will doubtless result in a fresh explosion of clever projects using the chip, but perhaps more intriguingly it will inevitably result in its appearance at the heart of a new crop of niche products that go beyond simple clones of the Pico in different form factors. The special ingredient of those two PIO programmable state machines to take the load of repetitive tasks away from the cores raises it above being merely yet another microcontroller chip, and we look forward to that feature being at their heart.
The Broadcom systems-on-chip that power Raspberry Pi’s existing range of Linux-capable boards have famously remained unavailable on their own, meaning that this move to being a chip vendor breaks further new ground for the Cambridge-based company. It’s best not to think of it in terms of their entering into competition with the giants of the microcontroller market though, because a relative minnow such as the RP2040 will be of little immediate concern to the likes of Microchip, ST, or TI. A better comparison when evaluating the RP2040’s chances in the market is probably Parallax with their Propeller chip, in that here is a company with a very solid existing presence in the education and maker markets seeking to capitalise on that experience by providing a microcontroller with that niche in mind. We look forward to seeing where this will take them, and we’d hope to eventually see a family of RP2040-like chips with different package and on-board peripheral options.
For a satisfying Youtube watching session there is noting like some quality machine shop work, and that’s exactly what [Made In Poland] supply with their conversion of a small 12V winch to power from a chainsaw. The finished product contains not much more than the gearbox and shaft components from the original, but the mesmerising sight of rusty steel stock being transformed into dimension-perfect components which come together to form an entirely new assembly is as always a draw.
The conversion starts with the removal and disassembly of the motor to reveal its shaft and the locking mechanism for the drum. The shaft is then turned down and a collar manufactured to couple it to the drive spline on a chainsaw. We’re pleased to see that the chainsaw isn’t modified in this build, instead the blade is simply unscrewed and the winch attached in a reversible process. Finally, the original drum is deemed too small for the application, so a new drum is fabricated. We see the result on a Polish farm, happily participating in some forestry work and even pulling their pickup truck when it became stuck.
For years now we have been told that self-driving cars will be the Next Big Thing, and we’ve seen some companies — yes, Tesla but others too — touting current and planned features with names like “Autopilot” and “self-driving”. Cutting through the marketing hype to unpacking what that really means is difficult. But there is a standard for describing these capabilities, assigning them as levels from zero to five.
Now we’re greeted with the news that Honda have put a small number of vehicles in the showrooms in Japan that are claimed to be the first commercially available level 3 autonomous cars. That claim is debatable as for example Audi briefly had level 3 capabilities on one of their luxury sedans despite having few places to sell it in which it could be legally used. But the Honda Legend SENSING Elite can justifiably claim to be the only car on the market to the general public with the feature at the moment. It has a battery of sensors to keep track of its driver, its position, and the road conditions surrounding it. The car boasts a “Traffic Jam Pilot” mode, which “enables the automated driving system to drive the vehicle under certain conditions, instead of the driver, such as when the vehicle is in congested traffic on an expressway“.
Sounds impressive, but just what is a level 3 autonomous car, and what are all the other levels?
This year’s Hackaday Prize has “Rethink Displays” as one of its first theme, and [Tucker Shannon] has given us his best shot on that subject with a set of impressive displays that “write” on glow-in-the-dark material using ultra-violet light. These materials glow for a while after UV illumination, so moving a light source like a UV LED over the surface draws glowing text or simple graphics which can be readily consumed.
One of the examples this a clock we were first smitten with back in 2018. It is a rather attractive 3D-printed affair with those servos mounted below the screen that moves a UV LED through a pair of linkages. Other offerings that play on the same UV stylus medium include a laser on an az-el mount controlled by a Raspberry Pi Zero. It’s a neat idea very effectively done, and we can see it has a lot of potential.
But the most impressively advanced so far is the model shown in the image at the top of the article and the demo video at the bottom. A loop of phosphorescent material is the display surface itself. This one moves that loop with two rollers to make up the X axis, and moves the UV source up and down for the Y axis. As with all of these designs, whatever is written will soon fade, leaving the surface ready for the next bit of information.
Interested in this project and think you could do a display of your own? The Hackaday Prize 2021 is live, and we’d love to see you enter it!
Some friends of mine are designing a new board around the STM32F103 microcontroller, the commodity ARM chip that you’ll find in numerous projects and on plenty of development boards. When the time came to order the parts for the prototype, they were surprised to find that the usual stockholders don’t have any of these chips in stock, and more surprisingly, even the Chinese pin-compatible clones couldn’t be found. The astute among you may by now have guessed that the culprit behind such a commodity part’s curious lack of availability lies in the global semiconductor shortage.
The fall-out from all this drama in the world’s car factories has filtered down through all levels that depend upon semiconductors; as the carmakers bag every scrap of chip fab capacity that they can, so in turn have other chip customers scrambled to keep their own supply lines in place. A quick scan for microcontrollers through distributors like Mouser or Digi-Key finds pages and pages of lines on back-order or out of stock, with those lines still available being largely either for niche applications, unusual package options, or from extremely outdated product lines. The chances of scoring your chosen chip seem remote and most designers would probably baulk at trying to redesign around an ancient 8-bit part from the 1990s, so what’s to be done?
Such things typically involve commercially sensitive information so we understand not all readers will be able to respond, but we’d like to ask the question: how has the semiconductor shortage affected you? We’ve heard tales of unusual choices being made to ship a product with any microcontroller that works, of hugely overpowered chips replacing commodity devices, and even of specialist systems-on-chip being drafted in to fill the gap. In a few years maybe we’ll feature a teardown whose author wonders why a Bluetooth SoC is present without using the radio functions and with a 50R resistor replacing the antenna, and we’ll recognise it as a desperate measure from an engineer caught up in 2021’s chip shortage.
So tell us your tales from the coalface in the comments below. Are you that desperate engineer scouring the distributors’ stock lists for any microcontroller you can find, or has your chosen device remained in production? Whatever your experience we’d like to know what the real state of the semiconductor market is, so over to you!
