Hams See Dark Side Of The Moon Without Pink Floyd

October 15, 2018 by Al Williams 36 Comments

Ham radio operators bouncing signals off the moon have become old hat. But a ham radio transmitter on the Chinese Longjiang-2 satellite is orbiting the moon and has sent back pictures of the Earth and the dark side of the moon. The transceiver’s main purpose is to allow hams to downlink telemetry and relay messages via lunar orbit.

While the photo was received by the Dwingeloo radio telescope, reports are that other hams also picked up the signal. The entire affair has drawn in hams around the world. Some of the communications use a modulation scheme devised by [Joe Taylor, K1JT] who also happens to be a recipient of a Nobel prize for his work with pulsars. The Dwingeloo telescope has several ham radio operators including [PA3FXB] and [PE1CHQ].

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Laser Noob: Getting Started With The K40 Laser

September 27, 2018 by Adam Fabio 77 Comments

Why spend thousands on a laser cutter/engraver when you can spend as little as $350 shipped to your door? Sure it’s not as nice as those fancy domestic machines, but the plucky K40 is the little laser that can. Just head on down to Al’s Laser Emporium and pick one up. Yes, it sounds like a used car dealership ad, but how far is it from the truth? Read on to find out!

Laser cutting and engraving machines have been around for decades. Much like 3D printers, they were originally impossibly expensive for someone working at home. The closest you could get to a hobbyist laser was Epilog laser, which would still cost somewhere between $10,000 and $20,000 for a small laser system. A few companies made a go with the Epilog and did quite well – notably Adafruit used to offer laptop laser engraving services.

Over the last decade or so things have changed. China got involved, and suddenly there were cheap lasers on the market. Currently, there are several low-cost laser models available in various power levels. The most popular is the smallest – a 40-watt model, dubbed the K40. There are numerous manufacturers and there have been many versions over the years. They all look about the same though: A blue sheet metal box with the laser tube mounted along the back. The cutting compartment is on the left and the electronics are on the right. Earlier versions came with Moshidraw software and a parallel interface.

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Using An FPGA To Navigate China’s Railroads

September 23, 2018 by Bryan Cockfield 19 Comments

If you’re headed over to mainland China as a tourist, it’s possible to get to most of the country by rail. China is huge though, about the same size as the United States and more than twice the size of the European Union. Traveling that much area isn’t particularly easy. There are over 300 train terminals in China, and finding the quickest route somewhere is not obvious at all. This is an engineering challenge waiting to be solve, and luckily some of the students at Cornell Engineering have taken a stab at efficiently navigating China’s rail system using an FPGA.

The FPGA runs an algorithm for finding the shortest route between two points, called Dijkstra’s algorithm. With so many nodes this can get cumbersome for a computer to calculate, but the parallel processing of a dedicated FPGA speeds up the process significantly. The FPGA also includes something called a “hard processor system“, or HPS. This is not a soft-core, but dedicated computing hardware in the form of an ARM Cortex-A9. Testing showed that utilizing both the HPS and the FPGA can speed up the computation by up to ten times over a microcontroller alone.

This project goes into extreme detail on the methodology and the background of the math and coding involved, and is definitely worth a read if you’re interested in FPGAs or traveling salesman-esque problems. FPGAs aren’t the only dedicated hardware you can use to solve these kinds of problems though, if you have a big enough backpack while you’re traveling around China you could also use a different kind of computer.

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Load Bank Teardowns Show Danger

July 2, 2018 by Al Williams 16 Comments

[Syonyk] has been acquiring some large load banks to test power supplies and battery packs. These devices consist of a big current sink, a measurement device, and a fan. He picked up two similar-looking boards from the usual Chinese sources, both rated for 150W, both for about $30. Upon closer examination, though, he found that one was really a bargain and the other was likely to blow up.

The loads are rated for 60V and as you can see from the photos, appear virtually identical at a glance. They offer a configurable cut-off voltage and even use 4-wire measurement to avoid problems with voltage drop through the power cables.

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Bunnie Weighs In On Tariffs

June 20, 2018 by Adam Fabio 150 Comments

[Bunnie] has penned his thoughts on the new 25% tariffs coming to many goods shipped from China to the US. Living and working both in the US and China, [Bunnie] has a unique view of manufacturing and trade between the two countries. The creator of Novena and Chumby, he’s also written the definitive guide on Shenzen electronics.

All the marked items are included in the new tariffs

The new US tariffs come into effect on July 6th. We covered the issue last week, but Bunnie has gone in-depth and really illustrates how these taxes will have a terrible impact on the maker community. Components like LEDs, resistors, capacitors, and PCBs will be taxed at the new higher rate. On the flip side, Tariffs on many finished consumer goods such as cell phone will remain unchanged.

As [Bunnie] illustrates, this hurts small companies buying components. Startups buying subassemblies from China will be hit as well. Educators buying parts kits for their classes also face the tax hike. Who won’t be impacted? Companies building finished goods. If the last screw of your device is installed in China, there is no tax. If it is installed in the USA, then you’ll pay 25% more on your Bill of Materials (BOM). This incentivizes moving assembly offshore.

What will be the end result of all these changes? [Bunnie] takes a note from Brazil’s history with a look at a PC ISA network card. With DIP chips and all through-hole discrete components, it looks like a typical 80’s design. As it turns out the card was made in 1992. Brazil had similar protectionist tariffs on high-tech goods back in the 1980’s. As a result, they lagged behind the rest of the world in technology. [Bunnie] hopes these new tariffs don’t cause the same thing to happen to America.

[Thanks to [Robert] and [Christian] for sending this in]

Making Electronics Just Got 25% More Expensive In The US

June 15, 2018 by Brian Benchoff 312 Comments

As reported by the BBC, the United States is set to impose a 25% tariff on over 800 categories of Chinese goods. The tariffs are due to come into effect in three weeks, on July 6th. Thousands of different products are covered under this new tariff, and by every account, electronic designers will be hit hard. Your BOM cost just increased by 25%.

The reason for this tariff is laid out in a report (PDF) from the Office of the United States Trade Representative. In short, this tariff is retaliation for the Chinese government subsidizing businesses to steal market share and as punishment for stealing IP. As for what products will now receive the 25% tariff, a partial list is available here (PDF). The most interesting product, by far, is nuclear reactors. This is a very specific list; one line item is, ‘multiphase AC motors, with an output exceeding 746 Watts but not exceeding 750 Watts’.

Of importance to Hackaday readers is the list of electronic components covered by the new tariff. Tantalum capacitors are covered, as are ceramic caps. Metal oxide resistors are covered. LEDs, integrated circuits including processors, controllers, and memories, and printed circuit assemblies are covered under this tariff. In short, nearly every bit that goes into anything electronic is covered.

This will hurt all electronics manufacturers in the United States. For a quick example, I’m working on a project using half a million LEDs. I bought these LEDs (120 reels) two months ago for a few thousand dollars. This was a fantastic buy; half a million of the cheapest LEDs I could find on Mouser would cost seventeen thousand dollars. Sourcing from China saved thousands, and if I were to do this again, I may be hit with a 25% tariff. Of course; the price on the parts from Mouser will also go up — Kingbright LEDs are also made in China. Right now, I have $3000 worth of ESP-12e modules sitting on my desk. If I bought these three weeks from now, these reels of WiFi modules would cost $3750.

There are stories of a few low-volume manufacturers based in the United States getting around customs and import duties. One of these stories involves the inexplicable use of the boxes Beats headphones come in. But (proper) electronics manufacturing isn’t usually done by simply throwing money at random people in China or committing customs fraud. These tariffs will hit US-based electronics manufacturers hard, and the margins on electronics may not be high enough to absorb a 25% increase in the cost of materials.

Electronics made in America just got 25% more expensive to produce.

It’s Raining Chinese Space Stations: Tiangong-1

March 29, 2018 by Steven Dufresne 50 Comments

China’s first space station, Tiangong-1, is expected to do an uncontrolled re-entry on April 1st, +/- 4 days, though the error bars vary depending on the source. And no, it’s not the grandest of all April fools jokes. Tiangong means “heavenly palace”, and this portion of the palace is just one step of a larger, permanent installation.

But before detailing just who’ll have to duck when the time comes, as well as how to find it in the night sky while you still can, let’s catch up on China’s space station program and Tiangong-1 in particular.

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