Author: Jenny List

3310 Articles

Review: What On Earth Is An Electromagnetic Radiation Tester And Why Would I Need One?

April 7, 2021 by 75 Comments

One of the joys of an itinerant existence comes in periodically being reunited with the fruits of various orders that were sent to hackerspaces or friends somewhere along the way. These anonymous parcels from afar hold an assortment of wonders, with the added element of anticipation that comes from forgetting exactly what had been ordered.

So it is with today’s subject, a Mustool MT525 electromagnetic radiation tester. At a cost not far above £10 ($13.70), this was an impulse purchase driven by curiosity; these devices claim to measure both magnetic and electric fields, but what do they really measure? My interest in these matters lies in the direction of radio, but I have never examined such an instrument. Time to subject it to the Hackaday treatment.

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AN ESP32 Walkie-Talkie, For Those Spy Radio Moments

April 7, 2021 by 29 Comments

One of the most thrilling childhood toys for the adventurous 1970s or 1980s kid was probably the toy walkie-talkie. It didn’t matter that they were a very simple AM low-end-VHF radio with a range of about 500m and a Morse key of debatable utility, you could talk clandestinely with your friends, and be a more convincing spy, or commando, or whatever was the game of the moment. It’s a memory conjured up for grown-ups by [Chris G] with his ESP32 walkie-talkie, which replaces a shaky 49MHz connection with one a bit more robust through the magic of WiFi.

The hardware is a collection of modules on a custom PCB, aside from the ESP32 there’s an I2S microphone and I2S audio amplifier, which along with battery and speaker are housed in a neat 3D printed case. I2S is used for simplicity, but there is no reason why analogue components couldn’t be used with a few code changes. Connection is made via UDP over a WiFi network, or should there be no network via ESP-NOW. We’re not sure the range will be brilliant with those little on-board chip antennas, but with the wide range of 2.4GHz antennas to be had it’s likely a better result could easily be achieved if the stock item disappoints.

We like this project, and it’s one that’s especially pleasing to see given that we saw the potential a few years ago in a less successful walkie-talkie using the ESP8266.

Bring A Hack Is Back This Thursday!

April 6, 2021 by 4 Comments

As the pandemic edges further into its second year, the tedium of life under lockdown is taking its toll. We may be fighting the spread of infection by staying home and having our meetings over video conferencing software, but it’s hellishly boring! What we wouldn’t do for our hackerspaces to be open, and for the chance to hang out and chew the fat about our lockdown projects!

Here at Hackaday we can bring some needed relief in the form of the Hackaday Remote: Bring-A-Hack held via Zoom on Thursday, April 8th, at 1pm Pacific time. We know you’ve been working hard over the last year, and since you’ve been denied the chance to share those projects in person, we know you just can’t wait to sign up. Last year’s Remoticon showed us the value of community get-togethers online, with both the team soldering challenge rounds and the bring-a-hack being particular event highlights, so it’s time for a fresh dose to keep up our spirits.

It doesn’t matter how large or small your project is, if it interests you other readers will also want to see it. Be prepared to tell the world how you made it, what problems you solved, and a bit about yourself, and then step back, take a bow, and be showered with virtual roses from the adoring masses. There’s a sign-up link if you have a project to show off Looks like we’re full up for planned presenations, but still come and bring your hacks for showing in conversation groups. Don’t hold back if you’re worried it’s not impressive enough, a certain Hackaday scribe has submitted an OpenSCAD library she’s working on.

Spacing Out: StarShip Explodes (Again), Passenger Space Flight, Space Bugs, Astronaut Bone, And Martian Water

April 5, 2021 by 24 Comments

This time I promise I only have a couple of stories from Elon Musk’s company. SpaceX’s latest Starship test launch ended in another explosion, proving that space hardware remains hard to get right. We’ll keep watching as they keep launching, and it can’t be long until they’ve ironed out all the problems. Meanwhile there’s brighter news from the company’s Crew Dragon, a modified version of the capsule with the forward docking ring replaced by a transparent dome is planned for launch in September with the company’s first flight carrying civilian passengers. It’s doubtless unwelcome news for Virgin Galactic, whose suborbital passenger flights are edging closer to reality with the unveiling of their first SpaceShip III craft. Finally, a Falcon 9 upper stage broke up on re-entry over the northwestern USA, giving observers on the ground a spactacular show.

Spectacular view of the Falcon 9 debris. Via Lu Jerz

Meanwhile up there in orbit there have been found on the ISS some strains of bacteria previously unknown to scientists on Earth, but it’s not yet time to panic about Mutant Bugs From Space. It seems these bacteria are of a type that is essential in the growing of plants, so it’s likely they originally hitched a ride up with one of the several plant-growing experiments that have taken place over the station’s lifetime. Staying on the ISS, astronauts visiting the station have been at the centre of a recently published study looking at loss of bone density over long periods in space. The bone experts found that bone density could still be lost despite the astronauts’ in-flight exercise programs, and concluded that exercise regimes pre-flight should be taken into account for future in-orbit exercise planning.

Further away from Earth, the ESA Mars Express satellite has been used for a multi-year study of water loss to space from the Martian atmosphere. The ESA scientists identified the seasonal mechanism that leads to the planet’s upper atmosphere having an excess of water and in particular the effect of the periodic planet-wide dust storms on accelerating water loss, but failed to account for the water that they estimate Mars must have lost over its history. From a study of water-created surface features they can estimate how much liquid the planet once had, yet the atmospheric losses fail to account for it all. Has it disappeared underground? More studies are required before we’ll have an answer.

The exciting news over the coming days will no doubt be the Ingenuity Martian helicopter, which we have seen slowly unfolding itself prior to unloading from the belly of the Perseverence rover. If all goes according to plan the little craft will be set down before the rover trundles off to a safe distance, and the historic flight will take place on April 8th. We’ll be on the edges of our seats, and no doubt you will be, too.

A Magnetic Field Strength Meter Using An Arduino

April 4, 2021 by 7 Comments

We’re used to Hall effect devices as proximity sensors in mechanical systems, used to provide detection of something that has a magnet attached to it. However it’s easy to forget that the devices that provide a magnet-or-not digital output are only part of the story, and linear Hall effect devices provide a handy way to measure a static magnetic field. It’s something [mircemk] demonstrates, with an Arduino-powered magnetic field strength meter that uses a UGN 3503U Hall effect device.

The circuit is extremely simple, comprising the sensor, an Arduino Nano, and an OLED display. This device is handy because its voltage output has a known relationship to the gauss level the sensor is experiencing, so while the accuracy of its calibration isn’t verified it can at least give a believable reading derived from the Arduino’s ADC.

The whole is wrapped up in an attractive case that looks as though it has been made from PCB material, with the sensor protruding on what seems to be the shell of a plastic ballpoint pen. It makes a handy instrument that provides a useful function for not a lot of money, so what’s not to like! Take a look at the video below the break for the full story.

Surprisingly such projects are few and far between here at Hackaday, however it’s not the first magnetic field measurement we’ve seen.

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Hiding Behind The Silkscreen: The Carolinacon 2021 Badge Has A Secret

April 4, 2021 by 7 Comments

The pandemic may have taken away many of our real-world events, but as they’ve gone online their badge teams have often carried on regardless. One of these comes from Carolinacon, and it’s decided to eschew the bleeding edge of electronic wizardry and instead push slightly at the boundaries of PCB art. It contains a hidden message in a copper layer behind a band of white silkscreen, which is revealed by a set of LEDs on the reverse of the board shining through the translucent FR4.

Electronics-wise it’s a pretty simple design, sporting only an ATtiny microcontroller and a photoresistor alongside the LEDs, and with the secret message being triggered when the badge is placed in the dark. The conference’s pig logo is eye-catching, but it has no pretences towards being a dev board or similar. The technique of LEDs behind copper and silkscreen is an interesting one though, and something that we think could bear more investigation in future designs. It’s pleasing to see that there are still new avenues to be taken in the world of PCB-based art.

This isn’t the first time this event has had an eye-catching badge, we’ve covered one of their previous offerings.

Reverse Engineering Silicon, One Transistor At A Time

April 3, 2021 by 10 Comments

Many of will have marveled at the feats of reverse engineering achieved by decapping integrated circuits and decoding their secrets by examining the raw silicon die. Few of us will have a go for ourselves, but that doesn’t stop the process being a fascinating one. Fortunately [Ryan Cornateanu] is on hand with a step-by-step description of his journey into the art of decapping, as he takes on what might seem an unlikely subject in the form of the CH340 USB to serial chip you’ll find on an Arduino Nano board.

Starting with hot sulphuric acid is probably not everyone’s idea of a day at the bench, but having used it to strip the epoxy from the CH340, he’s able to take a look under the microscope. This is no ordinary microscope but a metallurgists instrument designed to light the top of the sample from one side with polarised light. This allows him to identify an area of mask ROM and zoom in on the transistors that make each individual bit.

At this point the chemistry moves into the downright scary as he reaches for the hydrofluoric acid and has to use a PTFE container because HF is notorious for its voracious reactivity. This allows him to take away the interconnects and look at the transistor layer. He can then with a bit of computer vision processing help extract a bit layer map, which with some experimentation and guesswork can be manipulated into a firmware dump. Even then it’s not done, because he takes us into the world of disassembly of what is an unknown architecture. Definitely worth a read for the armchair chip enthusiast.

If you’re thirsty for more, of course we have to direct you towards the work of [Ken Shirriff].