MQTT Dashboard Uses SHARP Memory LCD

November 29, 2020 by Jenny List 7 Comments

One of the more interesting display technologies of the moment comes from Sharp, their memory display devices share the low power advantages of an e-ink display with the much faster updates we would expect from an LCD or similar. We’ve not seen much of them in our community due to cost, so it’s good to see one used in an MQTT dashboard project from [Raphael Baron].

The hardware puts the display at the top of a relatively minimalist 3D printed encloseure with the LOLIN32 ESP32 development board behind it, and with a plinth containing a small rotary encoder and three clicky key switches in front. The most interesting part of the project is surprisingly not the display though, because despite being based upon an ESP32 development board he’s written its software with the aim of being as platform- and display-independent as possible. To demonstrate this he’s produced it as a desktop application as well as the standalone hardware. A simple graphical user interface allows the selection of a range of available sources to monitor, with the graphical results on the right.

All code and other assets for the project can be found in a handy GitHub repository, and to put the thing through its paces he’s even provided a video that we’ve placed below the break. User interfaces for MQTT-connected devices can talk as well as listen, for example this MQTT remote control.

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Ham Radio Needs To Embrace The Hacker Community Now More Than Ever

November 28, 2020 by Jenny List 236 Comments

As many a radio amateur will tell you, ham radio is a hobby with as many facets as there are radio amateurs. It should be an exciting and dynamic place to be, but as those who venture forth into it sometimes sadly find out, it can be anything but. Tightly-knit communities whose interests lie in using $1,000 stations to chase DX (long-distance contacts), an advancing age profile, and a curious fascination of many amateurs with disaster communications. It’s something [Robert V. Bolton, KJ7NZL] has sounded off about in an open letter to the amateur radio community entitled “Ham Radio Needs To Embrace The Hacker Community Now More Than Ever“.

In it he laments that the influx in particular of those for whom disaster preparedness is the reason for getting a licence is to blame for amateur radio losing its spark, and he proposes that the hobby should respond by broadening its appeal in the direction of the hacker community. The emphasis should move from emergency communications, he says, and instead topics such as software defined radio and digital modes should be brought to the fore. Finally he talks about setting up hacker specific amateur radio discussion channels, to provide a space in which the talk is tailored to our community.

Given our experience of the amateur radio community we’d be bound to agree with him. The hobby offers unrivalled opportunity for analogue, mixed-signal, digital, and software tinkering in the finest tradition of the path set by the early radio amateurs around a hundred years ago, yet it sometimes seems to have lost its way for people like us. It’s something put into words a few years ago by our colleague Dan Maloney, and if you’re following [KJ7NZL]’s path you could do worse than read Dan’s long-running $50 ham series from the start.

Via Hacker News.

Header image: Unknown author, Public domain.

Finally! The ROM You Wished Your Sinclair Spectrum Had!

November 27, 2020 by Jenny List 10 Comments

If there is one thing that Sir Clive SInclair was famous for, it was producing electronic devices that somehow managed to squeeze near-impossible performance out of relatively meagre components. This gave us some impressive products, but it’s fair to say that sometimes this philosophy pushed the envelope a little too far. Thus even some of the most fondly remembered Sinclair products concealed significant flaws, and this extended to both their hardware and their software.

The SInclair ZX spectrum’s ROM for example had more than its fair share of bugs, and its BASIC programming experience with single keypress was unique but also slow to run. It’s something [Jonathan Cauldwell] has addressed with his Arcade Game Designer ROM, a complete and ready to run replacement for the original Spectrum ROM that contains a scripting language, a compiler, editors for in-game assets, and a game engine upon which to run your games. It’s the ROM you wanted back in 1983, when you were struggling to fit a bit of Z80 code in a Sinclair Basic REM statement.

If you’re a Spectrum enthusiast and think this sounds a little familiar then you are of course correct. It builds upon his past work with his Arcade Game Designer, with the distribution by ROM allowing the developer to use the full 48k available on all but a very few early 16k machines. You’ll need your own EPROM on which to burn it, but we suspect that if you’re the kind of person who has a Spectrum and has writing these games in mind, you already have access to the relevant equipment.

If you’re new to all this Spectrum stuff and where its ROM came from, then maybe it’s time for a trip down memory lane.

TinyTacho: Rotational Speed Measurement Without The Bulk

November 26, 2020 by Jenny List 10 Comments

An electronic tachometer is a straightforward enough device, in which the light reflections from a white spot on a rotating object are detected and counted over time, measuring the revolutions per minute (RPM). It’s a technique that has its roots in analogue electronics where the resulting pulses would have fed a charge pump, and it’s a task well suited to a microcontroller that simply counts them. But do you need an all-singing, all-dancing chip to do the job? [Stefan Wagner] has done it with a humble ATtiny13.

His TinyTacho is a small PCB with an IR LED and photodiode on one end, a small OLED display on its front, and a coin cell holder on its rear. The electronics may be extremely simple, but there’s still quite some effort to get it within the ATtiny’s meagre resources. Counting the revolutions is easy enough, but the chip has no I²C interface of its own and some bitbanging code is required. You can find all the design files and software you need in a GitHub repository, and he’s put up a video of the device in action that you can see below the break.

Tachometers are a popular project hereabouts, and we’ve featured a lot of them over the years. Perhaps the best place to direct readers then is not to another project, but to how to use a tachometer.

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Adding USB To A Keyboard The Way It Used To Be Done

November 26, 2020 by Jenny List 20 Comments

The world of custom keyboards has over the years developed its work into an art form, as mechanical key switches meet USB-HID capable microcontrollers for a plethora of designs as individual as their creators. This was however not always the case, and from the days of 8-bit home computers onwards making a custom keyboard often meant taking a surplus one from elsewhere and adapting its matrix to suit whatever controller interface was at hand. [Julian Calaby]’s USB conversion of an Apple Extended keyboard may be unusual in this day and age and was probably a late example even 15 years ago when he made it, but it remains a glorious piece of bodge-wire hardware hacking at its finest.

The task at hand with this type of conversion is to cut the matrix PCB tracks and replace them with soldered wires to create the new matrix required. This can then be wired to the controller, which in [Julian]’s case came from a cheap USB keyboard. He added a small USB hub to allow for a pair of USB sockets where Apple had put an ADB socket, making for quite a decent older keyboard with an unexpected USB interface.

Now older and wiser, he has plans to revisit his old keyboard with a modern microcontroller board, and needs to revisit the matrix again and give the peripheral new life. We still like the original though, as it captures a moment in time when keyboard matrix hacking made sense, and reminds us of our own youthful hardware follies.

Paging through Hackaday past it’s a testament to the old-school nature of this board that all we can find are microcontroller-based conversions. That’s not to say that cutting up old ‘boards is out of the question though.

Zoombombing The EU Foreign Affairs Council

November 25, 2020 by Jenny List 33 Comments

Those with security clearance are capable of making foolish mistakes, just like the rest of us. So is the story of how a Dutch journalist made an appearance on video meeting of the European Union’s Foreign Affairs Council (Dutch language, Google Translate link).

Ank Bijleveld's Tweeted picture, with the access details blacked out by Daniël Verlaan. — Netherlands Defence MInister Ank Bijleveld’s Tweeted picture, with the access details blacked out by Daniël Verlaan.

Like any other video call, if you had the link you could enter the meeting. So when Netherlands Defence Minister Ank Bijleveld Tweeted a photo of a video call last Friday, the address bar of the browser gave away the secret to anyone with a keen eye. Dutch journalist Daniël Verlaan working for the broadcaster RTL saw the URL on the screen and deduced the login credentials for the meeting.

We say “deduced”, but in fact there were five of the six digits in the PIN in the clear in the URL, leaving him with the difficult task of performing a one-digit brute-force attack and joining with the username “admin”. He joined and revealed his presence, then was admonished for committing a criminal offence before he left.

On one level it’s an opportunity for a good laugh at the expense of the defence ministers, and we certainly wouldn’t want to be Ank Bijleveld or probably the EU’s online security people once the inevitable investigation into this gets under way. It seems scarcely credible that the secrecy on such a high-security meeting could have sat upon such a shaky foundation without for example some form of two-factor authentication using the kind of hardware available only to governments.

EU policy is decided not by individual ministries but by delicate round-table summits of all 27 countries. In a pandemic these have shifted to being half-online and half in-real-life, so this EU defence ministers’ meeting had the usual mosaic video feed of politicians and national flags. And one Zoom-bombing journalist.

A Raspberry Pi 400 UPS Add-On, It’s Not All Plain Sailing

November 25, 2020 by Jenny List 51 Comments

Since the recent launch of the all-in-one Raspberry Pi 400, the global hardware community have taken to the new platform and are investigating its potential for hardware enhancements. On the back it has the same 40-pin expansion connector as its single-board siblings, but it’s horizontal rather than vertical, which means that all of the conventional HATs sit in a rather ungainly upright position.

One of the first Pi 400 HATs we’ve seen comes from [Patrick Van Oosterwijck], who has made a very neat 18650-based UPS add-on that is intended to eventually fit in the back of the machine in a similar way to the home computer cartridge peripherals of old. Unfortunately not all has gone according to plan, and in finding out why that is the case we learn something about the design of the 400, and maybe even take a chance to reflect on the Pi Foundation itself.

On the face of it the 400’s interface is the same as that of its single board computer stablemates, but something this project reveals is that its 5 V pins have a current limit of 1 A. This turns out to preclude the type of plug-in Pi UPS that sits on a HAT that we’re used to, in that 1 A through the 5 V pin is no longer enough to run the computer.

This effectively puts a stop to [Patrick]’s project, though he can repurpose it for a Pi 4 and its siblings once he’s dealt with a converter chip overheating problem. He does however make a complaint about the Pi Foundation’s slowness in releasing such data about their products, and given that long-time Pi-watchers will remember a few other blips in the supply of Pi hardware data he has a point. A quick check of the Raspberry Pi GitHub repository reveals nothing related to the Pi 400 at the time of writing, and though it shares much with its Pi 4 sibling it’s obvious that there are enough differences to warrant some extra information.

Hardware hackers may not be part of the core education focus of the Pi range, but a healthy, interested, and active hardware community that feels nurtured by its manufacturer remains key to the supply of interesting Pi-related products feeding into that market. We’d like to urge the Pi Foundation to never forget the hardware side of their ecosystem, and make hardware specification an integral part of every product launch on day one.

If the Pi 400 catches your interest, you can read our review here.