The Rise Of The Rural Hacker

September 7, 2015 by 56 Comments

On the far side of the Boso peninsula lies Kamogawa. This isn’t the Japan of LEDs, Otaku and maid cafes, or that of wage slave salarymen collapsing from exhaustion. This is the Japan of rice farmers and fields, fresh fish and wild boar, electron microscopes and gigabit fiber, SMD assembly and 500Mhz 5 Gigasample oscilloscopes.

The world has changed. In the 20th century the life of a rural hacker was a constant hunt for technological innovation. We scratched around for whatever we could find. A (usually national) periodical would give its monthly injection of technological curios. And knowledge was locked tight within expensive textbooks, which even if you could afford them might take weeks to arrive.

So, as had been the case for the preceding 1000 years, innovation clustered around technological hubs, San Francisco, Cambridge, and Tokyo among others. And Hackers flocked to these centers where innovation flourished while Hackers exchanged knowledge and tools.

But then the world of the rural Hacker began to expand. The technological hubs that so many rural hackers had migrated to began to connect the world. Young Hackers could learn to program (as I learned C) from textfiles posted on BBSs and exchange knowledge linking national communities. Shortly after that the Internet came bringing its Eternal September. Hackers across the world, regardless of location could communicate.

On the flip-side tech centers were changing too. Venture capital, rather than bootstrapping became the norm. With the influx of cash the demand for skilled Hackers rose, increasing wages and further focusing tech talent around these hubs. But rents and expenses rose too. And Hackers became locked into their expensive lifestyles; eyes firmly focused on the promised million dollar payoff and the eternal dream of an “exit”.

For some though, the freedom to Hack is more important than that million dollar exit and so a new model is emerging. Groups of Hackers in rural communities with low cost lifestyles and access to the world’s best technical talent and equipment that would put the best startups to shame.

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Using LTSpice To Measure Total Harmonic Distortion

September 7, 2015 by 7 Comments

Audiophiles spend a lot of time and effort worrying about audio specs like Total Harmonic Distortion (THD). Makes sense, because THD affects the quality of audio reproduction. However, THD can also affect interference from radio signals and even losses in power transfer systems. A simplified definition is the THD is the ratio of the sum of the power of all harmonic frequencies to the power of the fundamental frequency.

If a circuit produced a perfect sine wave, there would be no harmonics. There are many ways to measure THD in practice, but [Michael Jackson] has an interesting video showing how he easily visualizes THD using LTSpice. Assuming you already have the system in question in LTSpice (or you could use another simulation tool, if you prefer) it is fairly straightforward.

Continue reading “Using LTSpice To Measure Total Harmonic Distortion” →

LED Matrix Failure And Vindication

September 7, 2015 by 12 Comments

If necessity is the mother of invention, what’s failure the mother of? Improvement? Anyway, [prpplague]’s second version of his roll-up 70×30 RGB LED display looks a lot better and more reliable than the first, and that’s precisely due to “failing”.

Sometimes you design the hardware around the software, and sometimes vice-versa. It’s all about the balance of pain. [prpplague] initially wired the strips together in a consistently left-to-right raster arrangement to make the coding easier, but this means long wires on the backside of the fabric returning from the right side back to the start again at the left. These long wires snagged on stuff, and pulled the solder connections apart.

600px-Dotstar-adapter-solder3The fix? Alternate rows of left-to-right with right-to-left to minimize wiring and make nice, robust connectors for the ends, and a much more elegant implementation at the expense of more complicated software to drive the device. (Alternating rows have to be flipped horizontally, so this means custom driver routines.)

The second gremlin was that the interfacing board that [prpplague] was using didn’t have enough current sourcing capability on the SPI lines, and he discovered that he couldn’t communicate reliably with the strings if the first pixel was more than 24″ of wire away from the board. Once the signal got to the first pixel, though, everything was fine. [prpplague] figured out that the RGB LEDs themselves had more drive capability than the SPI source.

The solution? Add a single pixel at the front of the chain to buffer the SPI lines and serve as a bonus status indicator. Cute.

We’d hardly call these “fails”, but rather “learning experiences”. Anyway, here’s two design “mistakes” that we won’t make when making a roll-up flexible pixel display. Thanks [prpplague].

Hackaday Prize Semifinalist: Conserving Water And Eliminating Daydreaming

September 6, 2015 by 4 Comments

[mulcmu], we suppose, frequently wastes a lot of water while daydreaming in the shower. While daydreaming in the shower one day, we suppose again, he came up with the idea of keeping on task while in the shower. Thus was born the shower metronome, [mulcmu]’s entry for The Hackaday Prize.

The goal of the shower metronome is two-fold. First, it reduces the amount of water used in the shower. Secondly, it keeps the user on time for work. The shower metronome does this with a small audio beep provided by a small microcontroller attached to the shower frame or shower curtain.

The guts of the device are an MSP430 microcontroller, a few coin cell batteries, and a hall effect sensor that turns the device on, just like a magnetic door or window alarm. The microcontroller choice is perfect for the application; the MSP430 is extremely low power, and the device only draws 1uA in low power mode. This means the shower metronome will last a while when used only a few minutes a day.

The 2015 Hackaday Prize is sponsored by:

Better Batteries For Electronic Gadgets

September 6, 2015 by 46 Comments

We’re not using 9 Volt batteries to power our projects anymore; the world of hobby electronics has moved on to cheap LiPo batteries for most of our mobile power storage. LiPos aren’t the best solution, evidenced by hundreds of YouTube videos of exploding batteries, and more than a few puffy cells in our junk drawer. The solution? LiFePO4, or lithium iron phosphate cells. They’re a safer chemistry, they have low self discharge, and have more recharge than other chemistry of lithium cells.

LiFePO4 cells aren’t easy to deal with if you’re working with breadboard electronics, though. Most of that is because there aren’t many breakout boards for these cells. [Patrick] is working on changing that with his LiFePO4werd USB charger.

The concept is simple: use an off-the-shelf part for LiFePO4 batteries – in this case an MCP73123 – and make a board that charges the batteries with a USB port. It’s exactly the same idea as the many USB LiPo chargers out there, only this one uses a better battery chemistry.

[Patrick] is using a 550mAh battery for this project, but there’s no reason why it couldn’t be upgraded to a 18650-sized cell with more than 2000mAh stuffed inside. Add a boost converter to the circuit, and he’ll have the perfect power source for every portable electronics project imaginable.

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Hackaday Links: September 6, 2015

September 6, 2015 by 10 Comments

The MeArm is a cool little robot arm that can be controlled with just about any microcontroller. There’s a new version of it up on Thingiverse.

Here’s something to get kids interested in robotics: the GoBox is a robot kit with multiple ‘missions’ delivered monthly. The robot is based on the Raspberry Pi and Scratch – the Apple II and BASIC of today, I guess.

What happens when a popular electronics YouTuber completely debunks a product? Hundreds of dislikes appear on the YouTube videos he made. Hundreds of dislikes from Vietnam appeared on [Dave Jones]’ videos debunking the Batterizer. In fact, more people from Vietnam disliked the video than viewed it. Yes, weird YouTube dislike farms like this exist, and if you can do it on the Internet, you can also pay people to do it on the Internet.

The ESP8266 is slowly becoming a board that’s as easy to use as an Arduino. Now there’s a board that turns it into an Arduino.

The Vintage Computer Festival Midwest was last week,  and [chris537a] shot a video of all the cool stuff. [vikram4819] put an album up on imgur. Yes, someone was selling a Sparcbook for $300. I’m holding out for a PowerPC ThinkPad, though…

Washington DC area hackers, don’t forget to RSVP for the Hackaday Meetup on Saturday. Bring a hack to show off and spend the evening socializing with the Hackaday community. Check out the announcement post for more info.