hardware

1833 Articles

Waiting For China To Re-Open, From Huaqiangbei

February 20, 2016 by 24 Comments

The Chinese New Year is something we keep in mind at least half of the year, and probably still don’t plan for properly. In case you’re new to the situation: The Chinese New Year celebration empties out Shenzhen of its more than 12 million residents for the better part of a month. It’s the one time of year that manufacturing sector workers (and everyone that supports that ecosystem) travels home to visit family.

For those involved in manufacturing goods in Shenzhen, this part of the year leaves us cut off from one of our vices and we count the days until our tracking numbers and order confirmations start to show signs of life. It’s an inconvenience of an entirely different nature if you are one of the lonely few that stays in the city during the holiday. [Ian] over at Dangerous Prototypes wrote a blog post from his office in Huaqiangbei which is a sub-district of Shenzhen, China to share the experience with us.

Shenzhen is uniquely a migrant-worker city, and when emptied of the factory employees there are not enough people to patronize local services like markets and restaurants so they also shut down. But an empty city offers its own interesting entertainment like wicked fireworks sessions. As always, [Ian] does a great job of sharing this peculiar part of Shenzhen culture. He also kindly points out some of the offensive offers that come through the inter-webs from desperate customers who have poorly planned around the holiday.

Bench Testing A Switch Mode Drop In Replacement For The LM7805

February 15, 2016 by 50 Comments

Throwing a 5V regulator like the LM7805 at our projects can become habit forming, after all they’re dirt cheap and the circuit is about as basic as they come with only two external components, an input and output cap. As this is a good enough solution to most of our 5V circuits we can come into some issues if we aren’t paying attention. Linear regulators can only dissipate so much power in the form of heat before they need a heat sink and/or active cooling. Even if they can produce a cleaner output, in an embedded system, large power losses to heat are less than ideal to say the least.

[Daniel] needed an efficient solution to use in the place of an LM7805, after looking at the drop-in replacement switching solutions available on Adafruit’s website, he headed to DigiKey for a similar and less expensive part. [Daniel] collected some data and found the regulator to be 92% efficient with a 12V input, which is not quite the claimed 97% but a good solution nonetheless.

Switching voltage regulators are nothing new, so don’t even act like we just jumped on this switch-mode bandwagon! But it pays to give a little thought to your power supply. And while you’re in the mood, have an extremely thorough look inside the LM7805.

Nerf Turret Controlled By Slack

February 15, 2016 by 11 Comments

What happens when you give a former Navy weapons engineer some development boards and ask him to build “something cool”? What happens when you give a kid finger paints? [Seb] obviously built an IoT Nerf Turret Gun controlled via a team communication app.

The weapon was a Nerf Stampede which was hacked so it could be fired electronically. The safety switch was bypassed and a relay provided the firing signal. The electronics stack consists of an Intel Galileo, a motor shield and a relay shield. The turret assembly was built using off the shelf structural parts from Actobotics. Stepper motors provide motion to the turret. The fun begins with how the software is implemented. An iBeacon network detects where people sit at in the office. So when you type in the name of your target in a messaging app, it knows where they’re sitting, aims at them, and pops a nerf dart at them.

The lessons learned are what makes such projects worth their while. For example, USB is a standard. And the standard says that USB cables be not more than 1.8 m long. [Seb] was reminded of this when his electronics worked on his workbench, but refused to work when placed in-situ and connected via a 3m long cable – the serial link just wouldn’t work.

Mounting the gun such that it was nicely balanced was another challenge. Eventually, he had to use a couple of AA cells taped to the front of the gun to get it right. This could be useful though, since he plans to replace the dead weights with a sighting camera. One last hack was to zip tie heat sinks to the motor drivers, and he had a good reason to do that. Read more about it in his blog. And check out the video as someone takes aim and shoots a target via SLACK, the team messaging application.

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Open Sesame, From A Galaxy Far, Far Away.

February 14, 2016 by 15 Comments

[TVMiller]’s description of his project is epic enough to deserve a literal copy-paste (something our readers often praise us about). In his own words,  “Having discovered several spare Midichlorians in my liquor cabinet, I trained and applied them to opening a large cumbersome gate. The FORCE motion travels through my inner what-nots and is translated by the Pebble Classic accelerometer toggling a command sent to the (Particle) Cloud (City) which returns to the Particle Photon triggering a TIP120 to fire a button on an existing RF transceiver. May the ridiculous hand gestures be with you, always.” Thus was born the Gate Jedi , and you’ll need exactly 47 Midichlorians, and some other trivial parts, to build one.

The Pebble watch hooks up to his android smart phone. A Pebble (android) app sends the accelerometer data to the Particle (previously called Spark) cloud service. From there, the data is pushed to the Photon IoT board which runs a few lines of code. Output from the Photon turns on a TIP120 power transistor, which in turn triggers the existing RF trans receiver that opens the Gate.

This looks way cooler than the Light Sabre hacks. Check out the video of him summoning the Force. And if you’d like to do more, try integrating gesture controls with this Pebble Watch hack that turns it into a home automation controller.

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Brushed DC Servo Drive

February 13, 2016 by 37 Comments

Brushless DC motors, and their associated drive electronics, tend to be expensive and complicated. [Ottoragam] was looking for a cheaper alternative and built this Brushed DC motor servo controller and the results look pretty promising. Check out the video after the break.

He needed a low cost, closed loop drive for his home-brew CNC. The servo drive is able to supply a brushed DC motor with up to 7 A continuous current at up to 36 V which works out to about 250 W or 1/3 HP. It does closed loop control with feedback from a quadrature encoder. The drive accepts simple STEP and DIRECTION signals making it easy to interface with micro controllers and use it as a replacement for stepper motors in positioning applications. All of the control is handled by an ATmega328P. It takes the input signals and encoder data, does PID control, and drives the motor via the DRV8701 full bridge MOSFET driver. There’s also some error detection for motor over-current and driver under-voltage. Four IRFH7545 MOSFETs in H-bridge configuration form the output power stage.

This is still work in progress, and [Ottoragam] has a few features pending in his wish list. The important ones include adding a serial interface to make it easy to adjust the PID parameters and creating a GUI to make the adjustment easier. The project is Open Source and all source files available at his Github repository. The board is mostly surface mount, but the passives are all 0805, so it ought to be easy to assemble. The QFN footprint for the micro controller could be the only tricky one. [Ottoragam] would love to have some beta testers for his boards, and maybe some helpful comments to improve his design.

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Learn How A Radial Engine Works Or Gawk At Amazing Wood Model

February 4, 2016 by 19 Comments

[Ian Jimmerson] has constructed a detailed model of a radial engine out of wood and MDF for an undisclosed reason. Rather than just delivering the wooden engine to wherever wood engines go, [Ian] decided to take the time to film himself disassembling and reassembling his engine, explaining in detail how it works as he goes. He starts by teaching about the cylinder numbering and the different possible cylinder configurations. It only gets better after that, and it’s worth watching the full 20 minutes of video. You’ll leave with a definite understanding of how radial engines work, and maybe build something neat with the knowledge.

Our only complaint is the lack of build photos or construction techniques. It’s a real feat to build something with this many moving parts that can run off an electric drill. Was a CNC involved, or was he one of those hardcore guys who manage to get precision parts with manual methods? Part 1 and 2 after the break.

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ESP8266 Killer?

January 30, 2016 by 47 Comments

We’ve seen rumors floating around the Twittersphere about a new integrated microprocessor and WiFi SOC: the NL6621 from Nufront. Details are still scarce, but that doesn’t seem to be because the chip is vaporware: you could buy modules on Taobao.com and eBay right now for between two-and-a-half and three bucks, and Nufront’s website says they’ve produced a million modules since 2013.

The NL6621 WiFi SOC is powered by a 160 MHz ARM Cortex-M3 with 448 KB of RAM, and everything else is integrated in the SOC. The module has 32 GPIOs, SPI, I2C, I2S digital audio, and most of the peripherals that you’d expect. They say they have a completely open source SDK, but we can’t find a link to it anywhere. An English-language forum has sprung up in anticipation of the next new thing, and they say that they’ve contacted Nufront about the SDK, so that’s probably as good a place as any to lurk around if you’re interested. With an ARM core, it shouldn’t be long before someone gets GCC working on these things anyway.

It’s also worth noting that we’ve announced ESP8266 killers before, and it hasn’t come to pass. The mixture of community and official support that (eventually) came out of Espressif seems to be the main factor determining the ESP8266’s success, and we don’t see that yet with the NL6621. So take the question mark in the title seriously, but if this turns out to be the next big thing, remember where you heard it first, ok?

Thanks [David Hunt] for the tip!