What Is It, R2? Have Something To Share?

October 27, 2017 by James Hobson 5 Comments

Sometimes great projects keep evolving. [Bithead942] built himself an R2-D2 to accompany him when he goes a-trooping — but something didn’t feel quite right. Turns out, R2 was missing its signature beeping banter, so he made it more contextually responsive by implementing a few voice commands.

[Bithead942]’s main costume is that of an X-Wing pilot, and the replica helmet works perfectly; it already has a fake microphone — easily replaced with a working model — and the perfect niche to stash the electronics in the ‘mohawk.’

Even though the helmet has the perfect hiding spot for a circuit, space is still at a premium. Services like Alexa tend to be pretty accurate, but require WiFi access — not a guarantee on the convention floor. Instead, [bithead942] found that the EasyVR Shield 3.0 voice recognition board provided a suitable stand-in. It needs a bit of training to work properly(cue the montage!), but in the end it compares fresh audio commands to the ‘training’ files it has stored, and if there’s a match, triggers a corresponding serial port. It’s not perfect, but it most certainly works!

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This Power Strip Is A Fire Starter

October 27, 2017 by Adam Fabio 111 Comments

A few weeks ago I needed a power strip in my home office. The outlet in question is located behind a filing cabinet so it would need a low profile plug. I jumped on Amazon to buy a surge suppressor strip. That’s when I noticed strips with rotating plugs. I’ve always had some apprehensions about plugs like that, though I could never quite put my finger on why. Looking at the reviews on this particular plug, I found some scary issues. Photos of melted plugs, melted outlets, and cries of “fire hazard”. So I did what any crazy hacker would do – bought two power strips. One with a fixed right angle plug to use in my office, and one with a rotating plug to tear down.

Surge suppressors, power strips, outlet strips, they have many names. Underwriter’s Laboratories (UL) calls them “Relocatable power taps”. They all have several outlets, most have a circuit breaker of some sort inside, and some have circuits for surge suppression. These are some of the most common devices to find in the modern home. Many of our houses were designed and built before surround sound, cable boxes, computers, modems, cell phone chargers, tablet chargers, and all our other modern conveniences. There weren’t as many electrical loads, so the houses didn’t have many outlets. Power strips solve this problem.

After a couple of days, I had my strips in hand. I expected the plug to rotate once – maybe 270 degrees. That would indicate there were wires connecting the rotating head to rest of the plug. Not so – this plug would spin round and round all day long.

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DIY Barometer: It’s For Your Health!

October 27, 2017 by James Hobson 13 Comments

[Taciuc Marius] and his colleague noticed that days with low atmospheric pressure plus caffeine in their system meant a spike in blood pressure. Considering how this might impact his cardiovascular health, he decided to make a relative pressure barometer out of a jar to help him decide whether he should really have another cup of coffee.

Aside from a 3D printer, you’ll need to assemble a small jar with a lid, some screws, lock washers, nuts, and a flexible membrane — a piece of a rubber glove or balloon will do nicely. [Marius] details the build process on his project page, advising others to print the parts at 0.2 resolution — potentially even upping the extrusion multiplier to 1.1 — to prevent gaps in the print that would compromise the airtight seal needed for the barometer to work properly.

Additionally, thick glue or epoxy is recommended for the rest of the assembly process — it doesn’t have to be pretty, but it does need to be sealed! The final product can be easily tested by simply holding the jar.

While this barometer helps one make healthy choices, not all are created equal. This one tells you flat out how you should consider getting to work, while others have been tricked into behaving like touch sensors.

How To Bend PVC The Nice Way

October 27, 2017 by Lewin Day 32 Comments

PVC pipe is a valuable material to the backyard hacker. It’s cheap, readily available, and comes in a range of different sizes. However, what do you do if you need to bend it? The typical approach would be to grab a heat gun or blowtorch, warm it up, and go from there. These methods can get messy however, with kinks and melted surfaces spoiling the final result. Now [Linn] has released a video with a method that delivers impressively neat results.

A bending jig can help create repeatable results.

The method is simple, using that classic hacker staple — duct tape. The end of the pipe is taped off, and the pipe filled with sand. With the correct amount measured out, the sand is heated on a cooktop, then poured back into the pipe. After giving the heat some time to soften the plastic, the pipe can then be manipulated into the desired shape.

[Linn] does a great job of explaining the process in a clear and concise manner, and shares tips on how to use a bending jig to guide the final shape. Results are best with smaller pipes that are easier to heat through, but larger sections can be manipulated with patience.

We can’t wait to see what [Linn] builds with this new technique. The possibilities could be further expanded by combining with these PVC fittings designed just for building stuff.

[Thanks to George for the tip!]