You’ve Got Mail?

Life is full of tough decisions, such as deciding whether you want to go to the end of the drive to check if the mail has arrived. These questions are made even more arduous in the winter months, but [Catpin] has a solution. The Mail Box Alert uses an Electric Imp, a solar panel and a proximity sensor to let you know if you’ve got mail.

It’s a neat build, with the brains provided by that Electric Imp which handles most of the heavy lifting. This wakes up every five minutes and checks whether the status of a small proximity sensor has changed. If it has, it pings a website. The unit sits at the bottom of the postbox, so if your friendly neighborhood post person has put in any letters, it will have changed. The Imp is powered by a small battery, which is in turn charged by a solar panel. That means that it doesn’t require any power cables or other wiring, as long as it is in the range of WiFi. With the addition of a 15-hours overnight deep sleep, [Catpin] found that the whole thing could be run from a couple of 18650 LiPo batteries.

Perhaps the most interesting part of the writeup was discussing the problems that he found with the build, such as the fact that a LiPo battery won’t perform that well in a Wisconsin winter. So, this was replaced with a Lithium Iron Phosphate battery that should be a bit more tolerant of the chill. There is also a writeup on how to create the same project using an ESP8266 if required.

IREnE Goes Around

Timelapse rigs are awesome because you can spice up your videos with more interesting panning and tilting timelapse shots. So, why not build yourself one? That’s what [td0g] decided to do, and the result is IREnE, a rather nice homemade 3DOF rig that fits onto a standard tripod. 3DOF means that it has three degrees of freedom: the camera can be rotated on the tripod, moved linearly on an extending arm away from the tripod head and rotated around its own axis. In other words: it can pan past an object while rotating the camera to keep the object centered in the frame.

IREnE stands for Inverted Radial Extension Eggtimer, a play on the dual radial nature of the device and how photographers use egg timers for this sort of thing. It’s also a sneaky tribute to a foe of Sherlock Holmes. The rig is driven by three NEMA 17 motors and an ATMega328p, all powered by a Dewalt powertool battery and his own DeWatt power adapter. the rig also has a secondary function with minor modifications as a pancake printer.

Breakfast aside, there are a few caveats to this project. While a tripod is fine for stabilizing a camera on the top of it, offsetting the weight like this makes the tripod unstable. [td0g] did add a few welded stabilizer bars that brace it to more stable, but the whole thing should be used with some caution. The camera sits on a 1-inch square aluminium extruder that [td0g] claims is robust enough to hold his Canon D7, but I am not sure I would trust it with my expensive equipment.

This is the fifth high-quality build we have seen from [td0g]: we previously covered the excellent high-speed LED flash, great telescope mount, high-speed chronograph, and wood-burning ATX power supply hack.

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We Are Bowled Over By The BouLED

We’ve seen a lot of cubic LED creations recently, but this one takes it a bit further. The BouLED is a work-in-progress icosahedric LED display, a globe-like sphere made of 20 flat triangular LED-lit faces. When combined with sensors inside the display, it will be able to stabilize the image. In other words: you can pick it up and rotate it, but the image will stay steady. It is created as part of their degree work by [Matthias Rabault], [Lucas Lebailly] and [Hichem Ghandri] who are students at the Télécom Paris school.

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Robotic Laundry Line Reels You In

It may not be a laundry-folding robot, but this robotic launders line build by [Radical Brad Graham] is pretty neat. He has a 75-foot hanging laundry line from his house to a woodshed, and decided to roboticize it using some bits that were lying around. The result is a simple build that adds push-button control to pull the line back and forward, making it easier to hang everything out to dry. It’s a simple build, but [Brad] did a great job of documenting what he did and why, from mounting the posts that support the line to wiring up the control buttons.

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OpenLeg – The Open Source Robot Leg

There’s an old saying about standing on the shoulders of giants, but how about doing so with an open source leg? Well, your robots might do so at least, thanks to OpenLeg, a new open source project for building robot legs. Created by [Joey Byrnes], this started out as a senior project for a course at the University of Illinois. The idea is to create a robot leg that others can use to build four-legged robots that can amble around the neighborhood, much like those built by Boston Dynamics. Continue reading “OpenLeg – The Open Source Robot Leg”

Simple Bluetooth Car Audio From A Pi Zero

When [Sami Pietikäinen] realized that the Bluetooth built into his car didn’t support audio, he didn’t junk it and buy a Tesla. Instead, he decided to remedy the problem by building a small Bluetooth device that plugged into the Aux socket. To do this, he used a Raspberry Pi Zero with a pHAT DAC (Digital to Audio Converter). That’s perhaps using a sledgehammer to crack a walnut, but sometimes you work with what you have. The interesting part is to be found in what he did next: he used Yocto to optimize the device down to make it as simple and straightforward as possible.

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Expensive Sony Lens Repair Reveals Shims & Shifts

The photographic hire company Lensrentals had a $2k Sony FE 135mm f1.8 GM camera lens returned with a problem: it was having issues focusing. So, they decided to do the obvious thing and take it apart. It’s a fascinating insight into some of the engineering that goes into a high-end camera lens.

That is perhaps a rather scary thing to do, because this is a very new lens that doesn’t even have a service manual yet. That’s akin to rechipping a Ferrari when you’ve never even opened the hood before.

One of the interesting things inside is the presence of a number of shims that adjust the placement between the groups of lens elements. It seems that however good their manufacturing tolerances are, sometimes you just have to put a shim or two in there to align things.

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