This Extra-Large, Two-Stage Fume Extractor Really Sucks

Solder fumes are not nice on the lungs; nor are fumes from superglue, epoxy, or a whole mess of other things we often find ourselves using on the bench. Some people might be able to go the fume hood route to toss that all outside, but for the rest of us, there’s fume extractors. [Raph] has produced an extra-large, carbon-filtering, two-stage fume extractor that by all accounts really sucks — it is effective at hoovering up solder fumes up to 10″ from its inlet.

Photo of fume extractor
Note the 18V tool battery in the base. That’ll go for a bit.

Even better, [Raph] built a battery box for an 18 V cordless tool battery, and broke out banana plugs so this doubles as a variable power supply via a cheap LM2596 based DC-DC converter. It also serves as a speed controller for the fans, which makes us wonder if you can adjust the PSU output and the fan speed independently…

Maximum suckage is achieved through careful baffle design. Check out the blog to see the trial-and-error process at work. Of course, having a 200 mm axial fan and 140 mm blower fan front and rear is going to move some air no matter what. Which is required to get air flow through the 38 mm thick activated carbon filter that should scrub all nasties quite nicely. We aren’t filtration experts but we can agree with [Raph]’s estimate that it will last “a while”.

If you want to roll your own, all of the STEP files are on GitHub, and [Raph]’s blog has an excellent step-by-step build guide. We’ve seen other hacks from [Raph] before, from his dovetailed modular breadboard to the machine that shaped his bed and automation for his camper van.

A high level pictorial schematic of the basement monitor.

Making Sure The Basement Stays Dry With An ESP8266

The hack we have for you today is among our most favorite types of hack: a good, honest, simple, and well documented implementation that meets a real need. Our hacker [Solo Pilot] has sent in a link to their basement monitor.

The documentation is quite good. It’s terse but comprehensive with links to related information. It covers the background, requirements, hardware design, sensors, email and SMS alerts, software details, and even has some credits at the end.

Implementing this project would be a good activity for someone who has already made an LED flash and wants to take their skills to the next level by sourcing and assembling the hardware and then configuring, compiling, deploying, and testing the software for this real-world project.

To make this project work you will need to know your way around the Arduino IDE in order to build the software from the src.zip file included with the documentation (hint: extract the files from src.zip into a directory called AHT20_BMP280 before opening AHT20_BMP280.ino and make sure you add necessary boards and libraries).

One feature of the basement monitor that we would like to see is a periodic “everything’s okay” signal from the device, just so we can confirm that the reason we’re not getting an alarm about flooding in the basement is because there is no flood, and not because the battery ran dead or the WiFi went offline.

If you’ve recently started on your journey into where electronics meets software a project such as this one is a really great place to go next. And of course once you are proficient with the ESP8266 there are a thousand such projects here at Hackaday that you can cut your teeth on. Such as this clock and this fault injection device.

New Bismuth Transistor Runs 40% Faster And Uses 10% Less Power

Recently in material science news from China we hear that [Hailin Peng] and his team at Peking University just made the world’s fastest transistor and it’s not made of silicon. Before we tell you about this transistor made from bismuth here’s a whirlwind tour of the history of the transistor.

The Bipolar Junction Transistor (BJT, such as NPN and PNP) was developed soon after the point-contact transistor which was developed at Bell Labs in 1947. Then after Resistor-Transistor Logic (RTL) came Transistor-Transistor Logic (TTL) made with BJTs. The problem with TTL was too much power consumption.

Continue reading “New Bismuth Transistor Runs 40% Faster And Uses 10% Less Power”

Let The Wookie Win With This DIY Holochess Table

If you have seen Star Wars, you know what is being referenced here. Holochess appeared as a diversion built into the Millennium Falcon in the very first movie, way back in 1977. While not quite as iconic a use of simulated holograms as tiny Princess Leia begging for hope, it evidently struck a chord with [Maker Mac70], given the impressive effort he’s evidently gone through to re-create the game table from the film.

The key component of this unit is a plate from Japanese firm ASKA3D that scatters light from displays inside the table in just such a way that the diverging rays are focused at a point above its surface, creating the illusion of an image hovering in space. Or in this case, hovering at the surface of a acrylic chessboard. Granted, this technique only works from one viewing angle, and so is not a perfect recreation of a sci-fi holoprojector. But from the right angle, it looks really good, as you can see in the video below.

There are actually six SPI displays, driven by an Arduino GIGA, positioned and angled to project each character in the game. Placing two of the displays on 3D printed gantries allows them to move, allowing two creatures to battle in the center of the table. As [Maker Mac70] admits, this is quite a bit simpler than the Holochess game seen in the film, but it’s quite impressive for real world hardware.

If this all seems a little bit familiar, we covered an earlier floating display by [Maker Mac70] last year. This works on similar principles, but uses more common components which makes the technique more accessible. If chess isn’t your forte, why not a volumetric display that plays DOOM? If you’re interested in real holograms, not Sci-Fi, our own [Maya Posch] did a deep dive you may find interesting. Continue reading “Let The Wookie Win With This DIY Holochess Table”

An oscilloscope display is shown, showing two plots. A blue plot is shown at one level, and over multiple exposures at different places, it jumps to a higher level. Another yellow trace is shown which, at some point after the blue trace has jumped to a higher level, also jumps cleanly to a higher level. The yellow line is labeled "CFD output," while the blue line is labeled "leading edge discriminator."

A Constant-Fraction Discriminator For Sub-Nanosecond Timing

Detecting a signal pulse is usually basic electronics, but you start to find more complications when you need to time the signal’s arrival in the picoseconds domain. These include the time-walk effect: if your circuit compares the input with a set threshold, a stronger signal will cross the threshold faster than a weaker signal arriving at the same time, so stronger signals seem to arrive faster. A constant-fraction discriminator solves this by triggering at a constant fraction of the signal pulse, and [Michael Wiebusch] recently presented a hacker-friendly implementation of the design (open-access paper).

A constant-fraction discriminator splits the input signal into two components, inverts one component and attenuates it, and delays the other component by a predetermined amount. The sum of these components always crosses zero at a fixed fraction of the original pulse. Instead of checking for a voltage threshold, the processing circuitry detects this zero-crossing. Unfortunately, these circuits tend to require very fast (read “expensive”) operational amplifiers.

This is where [Michael]’s design shines: it uses only a few cheap integrated circuits and transistors, some resistors and capacitors, a length of coaxial line as a delay, and absolutely no op-amps. This circuit has remarkable precision, with a timing standard deviation of 60 picoseconds. The only downside is that the circuit has to be designed to work with a particular signal pulse length, but the basic design should be widely adaptable for different pulses.

[Michael] designed this circuit for a gamma-ray spectrometer, of which we’ve seen a few examples before. In a spectrometer, the discriminator would process signals from photomultiplier tubes or scintillators, such as we’ve covered before.

Hardware Built For Executing Python (Not Pythons)

Lots of microcontrollers will accept Python these days, with CircuitPython and MicroPython becoming ever more popular in recent years. However, there’s now a new player in town. Enter PyXL, a project to run Python directly in hardware for maximum speed.

What’s the deal with PyXL? “It’s actual Python executed in silicon,” notes the project site. “A custom toolchain compiles a .py file into CPython ByteCode, translates it to a custom assembly, and produces a binary that runs on a pipelined processor built from scratch.” Currently, there isn’t a hard silicon version of PyXL — no surprise given what it costs to make a chip from scratch. For now, it exists as logic running on a Zynq-7000 FPGA on a Arty-Z7-20 devboard. There’s an ARM CPU helping out with setup and memory tasks for now, but the Python code is executed entirely in dedicated hardware.

The headline feature of PyXL is speed. A comparison video demonstrates this with a measurement of GPIO latency. In this test, the PyXL runs at 100 MHz, achieving a round-trip latency of 480 nanoseconds. This is compared to MicroPython running on a PyBoard at 168 MHz, which achieves a much slower 15,000 nanoseconds by comparison. The project site claims PyXL can be 30x faster than MicroPython based on this result, or 50x faster when normalized for the clock speed differences.

Python has never been the most real-time of languages, but efforts like this attempt to push it this way. The aim is that it may finally be possible to write performance-critical code in Python from the outset. We’ve taken a look at Python in the embedded world before, too, albeit in very different contexts.

Continue reading “Hardware Built For Executing Python (Not Pythons)”

UK CanSat Competition, Space Ex, Lancing College, Critical Design Review

Lancing College Shares Critical Design Review For UK CanSat Entry

A group of students from Lancing College in the UK have sent in their Critical Design Review (CDR) for their entry in the UK CanSat project.

Per the competition guidelines the UK CanSat project challenges students aged 14 to 19 years of age to build a satellite which can relay telemetry data about atmospheric conditions such as could help with space exploration. The students’ primary mission is to collect temperature and pressure readings, and these students picked their secondary mission to be collection of GPS data, for use on planets where GPS infrastructure is available, such as on Earth. This CDR follows their Preliminary Design Review (PDR).

The six students in the group bring a range of relevant skills. Their satellite transmits six metrics every second: temperature, pressure, altitude reading 1, altitude reading 2, latitude, and longitude. The main processor is an Arduino Nano Every, a BMP388 sensor provides the first three metrics, and a BE880 GPS module provides the following three metrics. The RFM69HCW module provides radio transmission and reception using LoRa.

The students present their plan and progress in a Gantt chart, catalog their inventory of relevant skills, assess risks, prepare mechanical and electrical designs, breadboard the satellite circuitry and receiver wiring, design a PCB in KiCad, and develop flow charts for the software. The use of Blender for data visualization was a nice hack, as was using ChatGPT to generate an example data file for testing purposes. Mechanical details such as parachute design and composition are worked out along with a shiny finish for high visibility. The students conduct various tests to ensure the suitability of their design and then conduct an outreach program to advertise their achievements to their school community and the internet at large.

We here at Hackaday would like to wish these talented students every success with their submission and we hope you had good luck on launch day, March 4th!

The backbone of this project is the LoRa technology and if you’re interested in that we’ve covered that here at Hackaday many times before, such as in this rain gauge and these soil moisture sensors.