Author: Elliot Williams

1472 Articles

We’re Fans Of Dave’s Fans

August 13, 2016 by 73 Comments

Hackaday.io contributor extraordinaire [davedarko] gets hot in the summer. We all do. But what separates him from the casual hacker is that he beat the heat by ordering four 120 mm case fans. He then 3D printed a minimalistic tower frame for the fans, and tied them all together with a ULN2004 and an ESP8266. The whole thing is controlled over the network via MQTT. That’s dedication to staying cool.

We really like the aesthetics of this design. A fan made up of fans! But from personal experience, we also know that these large case fans can push a lot of air fairly quietly. That’s important if you’re going to stand something like this up on your desk. While we’re not sure that a desk fan really needs networked individual PWM speed control, we can see the temptation.

Now that they’re individually controlled, nothing stops [davedarko] from turning this into a musical instrument, or even using the fans to transmit data. The only thing we wouldn’t do, despite the temptation to stick our fingers in the blades, is to complicate the design visually. Maybe that would finally teach the cat not to walk around on our desk.

Hacker Builds New Single Board Computer Out Of Old Single Board Computer

August 13, 2016 by 11 Comments

[Ncrmnt] had a busted tablet PC with an Allwinner A23 SoC inside. He combined two of our favorite past-times, Linux hacking and 3D printing, to make a rather sweet little single-board-computer out of it, giving the tablet a second life.

Step one was to make sure that the thing works. Normally, you’d hook up a wired serial terminal and start hacking. [Ncrmnt] took it one step further and wired in a HC-05 Bluetooth serial module, so he can pull up the debug terminal wirelessly. The rest of the hackery was just crafting a bootable SD card and poking around in the Android system that was still resident in the flash memory of the system.

Once the board was proven workable, [Ncrmnt] designed and printed a sweet custom case using Solvespace, a constraint-based 3D CAD modeler that was new to us until recently. The case (after three prints) was a perfect fit for the irregularly shaped system board, a 3.7 V LiIon battery, and a speaker. He then added some nice mounting tabs. All in all, this is a nice-looking and functional mini-computer made out of stuff that was destined for the trash. It’s fast, it’s open-source, and it’s powerful. Best of all, it’s not in the dumpster.

There are pictures and more details on his blog, as well as [Ncrmnt]’s TV-stick to computer conversion that we’ve covered before.

Fun Audio Waveform Generator Is More Than The Sum Of Its Parts

August 10, 2016 by 22 Comments

[Joekutz] wanted to re-build an audio-rate function generator project that he found over on Instructables. By itself, the project is very simple: it’s an 8-bit resistor-ladder DAC, a nice enclosure, and the rest is firmware.

[Joekutz] decided this wasn’t enough. He needed an LCD display, a speaker, and one-hertz precision. The LCD display alone is an insane hack. He reverse-engineers a calculator simply to use the display. But instead of mapping each key on the calculator and typing each number in directly, he only taps the four 1, +, =, and clear keys. He can then enter arbitrary numbers by typing in the right number of ones and adding them up. 345 = 111 + 111 + 111 + 11 + 1. In his video, embedded below, he describes this as a “rather stupid” idea. We think it’s hilarious.

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Bluetooth HID Gamepad And HC-05 Serial Hack

August 10, 2016 by 20 Comments

“Which came first, the chicken or the egg?” Don’t bother us with stupid questions, they both co-evolved into the forms that we now serve up in tasty sandwiches or omelets, respectively. “Which came first, the HC-05 serial-flash-hack, or the wireless Bluetooth Gamepad?” Our guess is that [mitxela] wanted to play around with the dirt-cheap Bluetooth modules, and that building the wireless controller was an afterthought. But for that, it’s a well-done afterthought! (Video below the break.)

It all starts with the HC-05 Bluetooth module, which is meant to transfer serial data, but which can be converted into a general-purpose device costing ten times as much with a simple Flash ROM replacement. The usual way around this requires bit-banging over a parallel port, but hackers have worked out a way to do the same thing in bit-bang mode using a normal USB/Serial adapter. The first part of [mitxela]’s post describes this odyssey.

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Yak Shaving: Hacker Mode Vs Maker Mode

August 9, 2016 by 52 Comments

When I start up a new project, one that’s going to be worth writing up later on, I find it’s useful to get myself into the right mindset. I’m not a big planner like some people are — sometimes I like to let the project find its own way. But there’s also the real risk of getting lost in the details unless I rein myself in a little bit. I’m not alone in this tendency, of course. In the geek world, this is known as “yak shaving“.

The phrase comes obliquely from a Ren and Stimpy episode, and refers to common phenomenon where to get one thing done you have to first solve another problem. The second problem, of course, involves solving a third, and so on. So through this (potentially long) chain of dependencies, what looks like shaving a yak is obliquely working on cracking some actually relevant problem.
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[CNLohr], ESP8266, USB…

August 9, 2016 by 30 Comments

“Round up the usual suspects…”

[CNLohr] just can’t get enough of the ESP8266 these days — now he’s working on getting a version of V-USB software low-speed USB device emulation working on the thing. (GitHub link here, video also embedded below.) That’s not likely to be an afternoon project, and we should warn you that it’s still a project in progress, but he’s made some in-progress material available, and if you’re interested either in USB or the way the mind of [CNLohr] works, it’s worth a watch.

In this video, he leans heavily on the logic analyzer. He’s not a USB expert, and couldn’t find the right resources online to implement a USB driver, so he taught himself by looking at the signals coming across as he wiggled a mouse on his desk. Using the ever-popular Wireshark helped him out a lot with this task as well. Then it was time to dig into Xtensa assembly language, because timing was critical.

Speaking of timing, one of the first things that he did was write some profiling routines so that he could figure out how long everything was taking. And did we mention that [CNLohr] didn’t know Xtensa assembly? So he wrote routines in C, compiled them using the Xtensa GCC compiler, and backed out the assembly. The end result is a mix of the two: assembly when speed counts, and C when it’s more comfortable.

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Hackaday Prize Entry: Solar WiFi Rover Roves At Night

August 8, 2016 by 11 Comments

[TK] has a stretch goal for his RC car project — enabling it to recharge on solar power during the day and roam around under remote Internet control at night. It’s like a miniature, backyard version of NASA’s Curiosity rover.

Right now, he’s gotten a Raspberry Pi Zero and a camera on board, and has them controlling the robot over WiFi. He looks like he’s having a great time piloting it around his house. Check out the video down below for (crashy) remote-controlled operation.

We can’t wait to see if solar power is remotely possible (tee-hee!) as an option for this vehicle. The eventual plan to connect it via 3G cellular modem is still off in the future, and will probably demand more of the smarts of the Raspberry Pi than at present. But we love the idea of a long-running autonomous vehicle, so we’re pulling for you, [TK]!

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