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An Open Hardware Laser Engraver For Everyone

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Right now, you can get a diode laser engraver on eBay for around $100 USD. That sounds like a deal, but it’ll probably use some arcane proprietary software, won’t be terribly accurate, and the laser itself will almost certainly be fully exposed. Of course there’s no shortage of DIY builds which improve upon this situation greatly, but unfortunately the documentation and instructions to replicate them yourself often leave a lot to be desired.

To get a safe and accurate laser platform into the hands of hackers everywhere, we need more well documented open source designs that are actually built with community in mind. Projects like the Engravinator from [Adam Haile]. This isn’t a one-off design with documentation thrown together after the fact, it’s a fully open hardware engraver with a concise assembly guide that’s built from 3D printed parts and readily available components. You’re free to source and print the parts yourself or, eventually, purchase everything as a kit.

Pen-equipped Engravinator

The microwave-sized Engravinator is built from standard 2020 aluminum extrusion, and offers a workable area of 130mm x 130mm. There’s a hatch on the front of the enclosure for objects that are small enough to fit inside the machine, but the open bottom and handles on the top also allow the user to place the Engravinator directly onto the work surface. [Adam] says this feature can be especially useful if you’re looking to burn a design into a tabletop or other large object.

Outside of the aluminum extrusion and miscellaneous hardware that make up the frame, most of the other parts are 3D printed. Released under the CERN Open Hardware License v1.2 and distributed as both STL and STEP files, the printable parts for the Engravinator are ripe for modification should you be so inclined. The same goes for the DXF files for the enclosure panels, which will need to be cut out of orange acrylic with a CNC or (ironically) a laser.

Movement is provided by two NEMA 17 steppers and a GT2 belt arrangement, and [Adam] has even put together a custom control board he calls the Platypus using TMC2100 drivers; though you could always swap that out for a basic RAMPS board if you’re going down the DIY route. You can use any PWM-controlled diode laser with the common 16x40mm M3 bolt pattern, of which there’s no shortage of options on eBay.

[Adam] estimates the total cost of an Engravinator, assuming you start from absolutely nothing, is between $300 and $400 USD. But naturally that price will vary significantly on how much of the hardware you can find by rummaging through your parts bins or even by salvaging from something else. If you’ve got an outdated 3D printer collecting dust, you could pull a good deal of the hardware required from there.


We had a chance to see the Engravinator in action at the recent 2019 East Coast RepRap Festival, and definitely came away impressed. It’s a solid machine and the results on display all looked incredibly crisp. Our favorite feature (which appears to be optional) was the small camera mounted at the top of the enclosure that allowed the user to superimpose the image to be burned over the view of the workpiece to check alignment before burning.

Some will likely argue that the all-up cost of the Engravinator is still a bit too high for wide adoption, especially considering you can get a K40 for around the same price. But if you’d rather stick with a diode laser and don’t feel like taking your chances with the questionable hardware currently on the market, we think this is a project to keep an eye on.



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RF Modulation: Crash Course For Hackers

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When you’re looking to add some wireless functionality to a project, there are no shortage of options. You really don’t need to know much of the technical details to make use of the more well-documented modules, especially if you just need to get something working quickly. On the other hand, maybe you’ve gotten to the point where you want to know how these things actually work, or maybe you’re curious about that cheap RF module on AliExpress. Especially in the frequency bands below 1 GHz, you might find yourself interfacing with a module at really low level, where you might be tuning modulation parameters. The following overview should give you enough of an understanding about the basics of RF modulation to select the appropriate hardware for your next project.

Three of the most common digital modulation schemes you’ll see in specifications are Frequency Shift Keying (FSK), Amplitude Shift Keying (ASK), and LoRa (Long Range). To wrap my mechanically inclined brain around some concepts, I found that thinking of RF modulation in terms of pitches produced by a musical instrument made it more intuitive.

And lots of pretty graphs don’t hurt either. Signals from two different RF dev boards were captured and turned into waterfall and FFT plots using a $20 RTL-SDR dongle. Although not needed for wireless experimentation, the RTL-SDR is an extremely handy debugging tool, even to just check if a module is actually transmitting.

Amplitude Shift Keying

As the name suggests, with Amplitude Shift Keying the amplitude is shifted between two levels, like playing a single note (frequency) on a piano loudly or softly, to represent binary data. ASK modulation’s main advantage lies in its simplicity, which allows for very cheap hardware. It is also very bandwidth-efficient since it only outputs on a narrow frequency band. However, ASK modulation is badly affected by interference, which limits its effective range. A simplified form of ASK modulation is On-Off Shift Keying (OOK), where the transmitter is simply switched on (1) and off (0). This has a power saving advantage since no power is emitted for a 0 symbol. ASK is often used in cheap RF remote controls for consumer devices and automatic garage doors. RF modules that support more complex modulation schemes often can also do ASK and OOK modulation.

ASK (Left) and OOK (RIGHT), both transmitting at the same power level. Note how much less accumulative power is output by the OOK signal

Frequency Shift Keying

In Frequency Shift Keying the transmitted signal shifts between two different frequencies to represent binary data, like two different notes from a piano. This would technically be 2-FSK modulation. Four different frequencies can also be used (4-FSK) to represent 01, 11, 10 and 00. FSK uses more bandwidth, but is less susceptible to interference than ASK, allowing for a much longer effective range up to multiple kilometres. On real hardware, the rapid frequency changes can cause the desired frequency to be “overshot”, creating interference. To solve this, a common variation on FSK is Gaussian FSK, where the shifts between frequencies are smoothed to help reduce the effective bandwidth of the signal. Bluetooth Low Energy uses GFSK modulation.

2-FSK (Left) and 2-GFSK (Right). On GFSK the intermediate frequencies are visible from the “smooth” shift.

LoRa

LoRa modulation, with the sweeping “chirps” clearly distinguishable

The current darling for long range applications is LoRa, which most Hackaday readers would have heard of many times. LoRa is a form of “chirp spread spectrum” modulation. The “chirp” signal sweeps smoothly across specific frequency range: usually 125 kHz, 250 kHz or 500 kHz wide. How long the sweep takes to complete is determined by the “spreading factor” (SF). The SF is between 7 and 12, which is equal to the number of bits encoded in each chirp. A higher spreading factor reduces the data rate, and increases power consumption, but also makes it easier for the receiver to distinguish the signal from background noise, and helps with longer-range transmissions. Data is encoded by shifting the start frequency of the sweep. When the sweep reaches the end of the top frequency, it “rolls over” and start again from the bottom frequency.

LoRa modulation allows for good receiver sensitivity and interference immunity, but it comes at the cost of bandwidth efficiency. Another disadvantage is the higher cost of hardware, partly due to the patent on LoRa modulation. All manufacturers of LoRa RF chips must pay license fees to the patent holder, Semtech.

Closing Transmission

When working with RF, it’s always a good idea to know what your local regulations are with regard to allowed frequencies and output power. You don’t want authorities knocking on your door for jamming everyone in the neighbourhood’s key fobs. If you stay within the ISM bands, usually 868/915 MHz and 2.4GHz, licensing isn’t required. However, you can always get your ham radio license, and access more of the frequency spectrum, at much higher power output to even achieve intercontinental communications.

The modulation schemes above are only some many in existence, each with advantages and disadvantages. You’ll probably end up with a few choices in your parts inventory, so don’t be afraid to play around with them for different use cases. And be sure to pull out an SDR dongle and have a look!



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The next-gen Xbox’s secret weapon against the PS5 might’ve just leaked

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Both Sony and Microsoft are going to launch new consoles this holiday season, but it’s the latter might be doing things differently in 2020. Rather than launching just one console model, as Sony is expected to do with the PlayStation 5, Microsoft will reportedly release two new Xbox versions, one that will compete directly against the PS5 and one that will be slightly cheaper and less powerful. So far, Microsoft has only announced the Xbox Series X product name, but a more affordable Xbox Series S might also be in the works, according to recent leaks.

Previous reports referred to the two next-generation Xbox models by their supposed code names, Anaconda and Lockhart, but Microsoft never really acknowledged them. Now, a brand new leak seems to suggest that the Xbox Series S might be real, as someone has been testing an AMD processor that could power the cheaper version of Microsoft’s new console.

A detailed analysis of the mysterious AMD APU was posted over on Reddit, showing the chip’s benchmark scores in 3DMark 11 and Time Spy relative to known AMD chipsets. The APU includes a 4.0GHz octa-core processor and an unknown graphics processing unit, and it’s paired with 16GB of GDDRX memory shared between RAM (12GB) and VRAM (4GB) in these benchmarks.

From what can be gleaned from public benchmark scores and a private Time Spy scores, WinFuture says the unnamed AMD APU might deliver a graphics performance that would sit between 7.0 teraflops and 7.9 teraflops, which would be significantly higher than the rumored 4 teraflops performance of the cheaper 2020 Xbox model. This is just speculation though, as Microsoft is yet to reveal the actual specs of the new Xbox consoles.

Sony is widely expected to hold its PlayStation 5 event in February, but it’s unclear when Microsoft will reveal more details about the new Xbox models. A detailed PS5 leak said a few weeks ago that the affordable Xbox will be $100 cheaper than the $499.99 PS5, which, in turn, will be $100 less expensive than the Xbox Series X. Those claims are unverified as well, but once Sony unveils the PS5, we’ll be in a better position to tell whether the leaker had accurate information on hand.



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China doesn’t need a Huawei ‘backdoor’ to launch a cyber-attack against the UK, experts warn

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The Chinese firm Huawei is set to play a role in building part of the UK’s 5G network infrastructure (Image: Getty)

China has better ways of hitting the UK with a cyber attack than trying to exploit a ‘backdoor’ in Huawei equipment, UK experts have concluded.

As the Government gave the green light for the controversial Chinese tech firm to play a limited role in the UK’s 5G network, the National Cyber Security Centre (NCSC) said the risk of its involvement was ‘manageable’.

Huawei is already subject to oversight arrangements which ensure that any ’embedded malicious functionality could be detected should it exist’, the analysis said.

The US has warned allies not to allow the Chinese firm to play a part in their 5G networks, arguing that it is a security risk due to its close links to the Beijing government, something denied by Huawei.

The firm’s activities in the UK have been overseen by arrangements including the Huawei Cyber Security Evaluation Centre (HCSEC) – nicknamed the Cell.

The NCSC said: ‘Due to the UK’s mitigation strategy, which includes HCSEC as an essential component, our assessment is that the risk of trojan functionality in Huawei equipment remains manageable.

‘Placing “backdoors” in any Huawei equipment supplied into the UK is not the lowest risk, easiest to perform or most effective means for the Chinese state to perform a major cyber attack on UK telecoms networks today.’

The NCSC did raise concerns about any single supplier of equipment being allowed to play a dominant role in the network.

SIPA USA via PA Images A Huawei logo is seen on top of an office building in Bucharest, Romania on May 1, 2019. (Photo by Jaap Arriens/Sipa USA)

(Image: PA)

The guidance issued by NCSC excludes ‘high-risk vendors’ such as Huawei from ‘core’ parts of the network, and sensitive locations including nuclear sites and military bases.

They will also be limited to a minority presence of no more than 35% in the periphery of the network, known as the access network, elements which connect devices and equipment to mobile phone masts.

The NCSC stressed that it was ‘important to avoid the situation in which the UK becomes nationally dependent on a particular supplier’.

It added: ‘Without government intervention, the NCSC considers there to be a realistic likelihood that due to commercial factors, the UK would become “nationally dependent” on Huawei within three years.’

National dependence on a high-risk vendor would present a ‘significant national security risk’, the NCSC said.

NCSC technical director Dr Ian Levy said Huawei had always been treated as a high-risk vendor and the authorities have ‘worked to limit their use in the UK’.

‘We’ve never ‘trusted’ Huawei and the artefacts you can see (like the Huawei Cyber Security Evaluation Centre (HCSEC) and the oversight board reports) exist because we treat them differently to other vendors,’ he said.

‘We ask operators to use Huawei in a limited way so we can collectively manage the risk and NCSC put in place a wider mitigation strategy, of which HCSEC is the most visible part.’

Ciaran Martin, chief executive of the NCSC, said: ‘This package will ensure that the UK has a very strong, practical and technically sound framework for digital security in the years ahead.

‘The National Cyber Security Centre has issued advice to telecoms network operators to help with the industry roll-out of 5G and full-fibre networks in line with the Government’s objectives.

‘High-risk vendors have never been, and never will be, in our most sensitive networks.

‘Taken together these measures add up to a very strong framework for digital security.’



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