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Ho Chi Mihn City is the hub for sourcing the materials and tools driving the growing Vietnamese economy. Whether you’re building new, or keeping existing equipment running, the supply chains and service companies aren’t yet in place and the markets of HCMC are the go-to for parts and equipment. Let’s get a little taste of what I saw in my tour of the markets.
Continue reading “Hacker Abroad: Vietnam’s Electronics And Hardware Markets”
A few years ago, I was out at the W6TRW swap meet at the parking lot of Northrop Grumman in Redondo Beach, California. Tucked away between TVs shaped like polar bears and an infinite variety of cell phone chargers and wall warts was a small wooden box. There was a latch, a wooden handle, and on the side a DB-25 port. There was a switch for half duplex and full duplex. I knew what this was. This was a modem. A wooden modem. Specifically, a Livermore Data Systems acoustically coupled modem from 1965 or thereabouts.
The probability of knowing what an acoustically coupled modem looks like is inversely proportional to knowing what Fortnite is, so for anyone reading this who has no idea what I’m talking about, I’ll spell it out. Before there was WiFi and Ethernet and cable modems and fiber everywhere, you connected to the Internet and BBSes via phone lines. A modem turns digital data, in this case a serial connection, into analog data or sound. Oh yeah, we had phone lines, too. The phone lines and the phones in your house were owned by AT&T. Yes, you rented a phone from the phone company.
90s kids might remember plugging in a US Robotics modem into your computer, then plugging an RJ-11 jack into the modem. When this wooden modem was built, that would have been illegal. Starting with the communications act of 1934, it was illegal to attach anything to the phone in your house. This changed in 1956 with Hush-A-Phone Corp v. United States, which ruled you could mechanically attach something to a phone’s headset. (In Hush-A-Phone’s case, it was a small box that fit over a candlestick phone to give you more privacy.)
The right to attach something to AT&T’s equipment changed again in 1968 with Carterphone decision that allowed anyone to connect something electronically to AT&T’s network. This opened the door for plugging an RJ-11 phone jack directly into your computer, but it wasn’t until 1978 that the tariffs, specifications, and certifications were worked out. The acoustically coupled modem was the solution to sending data through the phone lines from 1956 until 1978. It was a hack of the legal system.
This leaves an ancient modem like the one sitting on my desk in an odd position in history. It was designed, marketed and sold before the Carterphone decision, and thus could not connect directly to AT&T’s network. It was engineered before many of the integrated chips we take for granted were rendered in silicon. The first version of this modem was introduced only a year or so after the Bell 103 modem, the first commercially available modem, and is an excellent example of what can be done with thirteen or so transistors. It’s time for the teardown, so let’s dig in.
After a youth spent playing with Amigas and getting into all sorts of trouble on the school computer network, I’ve always had a soft spot in my heart for hardware from the 80s and 90s. This extends beyond computers themselves, and goes so far as to include modems, photocopiers, and even the much-maligned dot matrix printer.
My partner in hacking [Cosmos2000] recently found himself with a wonderful Commodore MPS 1230 printer. Its parallel interface was very appropriate in its day, however parallel ports are as scarce as SID chips. Thankfully, these two interfaces are easy to work with and simple in function. Work on a device to marry these two disparate worlds began.
While I was gallivanting around the Eastern coast of Australia, [Cosmos2000] was hard at work. After some research, it was determined that it would be relatively simple to have an Arduino convert incoming serial data into a parallel output to the printer. After some testing was performed on an Arduino Uno, a bespoke device was built – in a gloriously plastic project box, no less.
An ATMEGA328 acts as the brains of the operation, with a MAX232 attached for level conversion from TTL to RS232 voltage levels. Serial data are received on the hardware TX/RX lines. Eight digital outputs act as the parallel interface. When a byte is received over serial, the individual bits are set on the individual digital lines connected to the printer’s parallel port. At this point, the strobe line is pulled low, indicating to the attached device that it may read the port. After two microseconds, it returns high, ready for the next byte to be set on the output lines. This is how parallel interfaces operate without a clock signal, using the strobe to indicate when data may be read.
At this point, [Cosmos2000] reached out – asking if I had a name for the new build.
“Hm. Paralleloslam?”
“Done. Cheers!”
Continue reading “Arduino Converts Serial To Parallel: The Paralleloslam”
One of the unfortunate things about Hackaday’s globe-spanning empire is that you often don’t get to meet the people you work with in person. Since I was in China and it’s right next door, I really wanted to pop over to Vietnam and meet Sean Boyce, who has been writing for Hackaday for a couple of years, yet we’ve never met. I suggested we could make this happen if we put together a meetup or unconference. Sean was immediately confident that the Ho Chi Minh City hardware hackers would turn out in force and boy was he right! On Sunday night we had a full house for the first ever Hackaday Vietnam Meetup.
Continue reading “Hacker Abroad: Vietnam’s Hardware Hackers”
We humans are good at a lot of things, but making holes in the ground has to be among our greatest achievements. We’ve gone from grubbing roots with a stick to feeding billions with immense plows pulled by powerful tractors, and from carving simple roads across the land to drilling tunnels under the English Channel. Everywhere we go, we move dirt and rock out of the way, remodeling the planet to suit our needs.
Other worlds are subject to our propensity for digging holes too, and in the 50-odd years that we’ve been visiting or sending robots as our proxies, we’ve made our marks on quite a few celestial bodies. So far, all our digging has been in the name of science, either to explore the physical and chemical properties of these far-flung worlds in situ, or to actually package up a little bit of the heavens for analysis back home. One day we’ll no doubt be digging for different reasons, but until then, here’s a look at the holes we’ve dug and how we dug them.
Continue reading “Extraterrestrial Excavation: Digging Holes On Other Worlds”
As near as we can tell, the popular WS2812 individually addressable RGB LED was released to the world sometime around the last half of 2013. This wasn’t long ago, or maybe it was an eternity; the ESP8266, the WiFi microcontroller we all know and love was only released a year or so later. If you call these things “Neopixels”, there’s a good reason: Adafruit introduced the WS28212 to the maker community, with no small effort expended on software support, and branding.
The WS2812 is produced by WorldSemi, who made a name for themselves earlier with LED driver solutions, especially the WS2811, an SOIC chip that would turn a common anode RGB LED into one that’s serially controllable. When they stuffed the brains from the WS2811 into a small package with a few LEDs, they created what is probably the most common programmable LED lighting solution available today.
A lot has changed in the six years that the WS2812 has been on the market. The computer modding scene hasn’t heard the words ‘cold cathode’ in years. Christmas lights are much cooler, and anyone who wants to add blinky to their bling has an easy way to do that.
But in the years since the WS2812 came on the market, there are a lot of follow-up products that do the same thing better. You now have serially addressable LEDs that won’t bring down the rest of the string when they fail. You have RGBW LEDs. There are LEDs with a wider color gamut and more. This is a look at the current state of serially addressable RGB LEDs, and what the future might have in store.
Shenzhen, China is the home of the legendary electronics markets of Huaqiangbei. Friday was my first full day in the city, having spent the previous three days in Shanghai. We got a little bit of a late start as our flight didn’t arrive until after 1 am and we stayed at the first night at an airport hotel. We met up with Scotty Allen for an amazing meal followed by a very unique experience in the electronics markets, not just seeing the items, but meeting the booth owners who showed off some of their secrets.
The day was capped off by an absolutely packed meetup at X.factory, the collaborative creative space run by Seeed Studio. They lined up a half dozen hardware talks that were quite excellent, and there was a ton of hardware being demonstrated as the night progressed. They had to kick us out or we’d have stayed all night!
Continue reading “Hacker Abroad: Cellphone Repair In Huaqiangbei And A Huge Meetup At Seeed”
