Homemade Wall Stops Roomba And Other Vacuum Tricks

September 20, 2019 by Al Williams 19 Comments

If you have a Roomba, you know they are handy. However, they do have a habit of getting into places you’d rather they avoid. You can get virtual walls which are just little IR beacons, but it is certainly possible to roll your own. That’s what [MKme] did and it was surprisingly simple, although it could be the springboard to something more complicated. You can see a video about the build below.

As Arduino projects go, this could hardly be more simple. An IR LED, a resistor and a handfull of code that calls into an IR remote library. If that’s all you wanted, the Arduino is a bit overkill, although it is certainly easy enough and cheap.

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Your Next Robot Needs Googly Eyes, And Other Lessons From Disney

September 17, 2019 by Al Williams 11 Comments

There are so many important design decisions behind a robot: battery, means of locomotion, and position sensing, to name a few. But at a library in Helsinki, one of the most surprising design features for a librarian’s assistant robot was googly eyes. A company called Futurice built a robot for the Oodi library and found that googly eyes were a very important component.

The eyes are not to help the robot see, because of course they aren’t functional — at least not in that way. However without the eyes, robot designers found that people had trouble relating to the service robot. In addition, the robot needed emotions that it could show using the eyes and various sounds along with motion. This was inspired, apparently, by Disney’s rules for animation. In particular, the eyes would fit the rule of “exaggeration.” The robot could look bored when it had no task, excited when it was helping people, and unhappy when people were not being cooperative.

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Speed Up Filming With This Jawdropping 8-Axis Camera Crane

September 17, 2019 by Lewin Day 30 Comments

These days, it can feel like a project doesn’t exist unless you’ve posted a video on the Internet about it. [mingul] was in the process of producing his own videos, but found having to repeatedly move and set up the camera tiring. Naturally, a completely overkill eight-axis motion control robot was the solution. Video embedded below the break.

The scale of the build is something to behold. With 4.5 m travel on the X-axis, 6.5 m on the Y, and 2.1 m on the Z, it’s capable of traversing the full length of [mingul]’s workshop. Tilt, pan, and roll axes all feature 540 degrees of rotation, and there’s motors to control zoom and focus on the camera, too. Through software like Dragonframe, it’s possible to program complicated camera moves, and techniques like the classic dolly zoom are a cinch with such a versatile rig. It’s also possible to control the movement in real-time with a wireless Xbox controller.

[mingul] reports the build took a full three months of CNC machining, 3D printing and assembly. It’s a big step above a simple motorized camera slider, but we all have to start somewhere.

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DJ Xiaomi Spins Beats And Brushes At The Same Time

September 13, 2019 by Tom Nardi 5 Comments

Direct from the “Just Because I Can” department, this blog post by [Eddie Zhang] shows us how easy it is to get the Xiaomi robotic vacuum cleaner working as what might be the world’s most unnecessary Spotify Connect speaker. Will your home be the next to play host to an impromptu performance by DJ Xiaomi? Judging by the audio quality demonstrated in the video after the break, we doubt it. But this trick does give us a fascinating look at the current state of vacuum hacking.

For the first phase of this hack, [Eddie] makes use of Dustcloud, an ongoing project to document and reverse engineer various Xiaomi smart home gadgets. Using the information provided there you can get root-level SSH access to your vacuum cleaner and install your own software. There’s a sentence you never thought you’d read, right?

With the vacuum rooted, [Eddie] then installs a Spotify Connect client intended for the Raspberry Pi. As they’re both ARM devices, the software will run on the Xiaomi bot well enough, but the Linux environment needs a little tweaking. Namely, you need to manually create an Upstart .conf file for the service, as the vacuum doesn’t have systemd installed. There goes another one of those unexpected sentences.

We’re certainly no stranger to robotic vacuum hacking, though historically the iRobot Roomba has been the target platform for such mischief. Other players entering the field can only mean good things for those of us who get a kick out of seeing home appliances pushed outside of their comfort zones.

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Handheld LoRa Joystick For Long-Range Bots

September 11, 2019 by Tom Nardi 11 Comments

Wanting a simple tool to aid in the development of LoRa controlled robotic projects, [Jay Doscher] put together this very slick one-handed controller based on the 900 MHz Adafruit Feather M0. With a single trigger and a miniature analog joystick it’s a fairly simple input device, but should be just enough to test basic functionality of whatever moving gadget you might find yourself working on.

Wiring for this project is about as simple as you’d expect, with the trigger and joystick hanging off the Feather’s digital ports. The CircuitPython code is also very straightforward, though [Jay] says in the future he might expand on this a bit to support LoRaWAN. The controller was designed as a barebones diagnostic tool, but the hardware and software in its current form offers an excellent opportunity to layer additional functionality on a known good base.

Everything is held inside a very well designed 3D printed enclosure which [Jay] ran off on his ELEGOO Mars, one of the new breed of low-cost resin 3D printers. The machine might be pretty cheap, but the results speak for themselves. While resin printing certainly has its downsides, it’s hard not to be impressed by the finish quality of this enclosure.

While LoRa is generally used for transmitting small bits of information over long distances, such as from remote sensors, this isn’t the first time we’ve seen it used for direct control of a moving object. If you’re not up to speed on LoRa, check out this excellent talk from [Reinier van der Lee] that goes over the basics of the technology and how he used it to build a community sensor network.

One-Motor Domino Laying Machine Works For Tips

September 9, 2019 by Donald Papp 21 Comments

[Gzumwalt] did things a little differently with his Pink and Green Domino Machine II, a 3D printed device that drops dominoes in a neat row ready for toppling over. Unlike his earlier version, this one holds dominoes laying flat in a hopper that’s accessible from the top for easy loading. The previous unit had an elegance to it, but it was more limited with respect to how many dominoes it could hold at a time. This new version solves that problem while also showing off a slick mechanism that gracefully slides a domino from the bottom of the hopper, then gently positions it standing on end before opening a rear door to let it out as it moves to the next position. One of the interesting things [gzumwalt] discovered when designing this device was that there isn’t really a “standard” size of domino. That’s one of the reasons the demo uses 3D printed blocks.

Pulling this off with a single small DC motor is a remarkable achievement; the mechanism even stably ejects a positioned domino from the rear without halting its forward motion in the process. An animation of how the mechanism works is embedded below, be sure to check it out!

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Mechpen: SCARA Drawbot For The Big Picture

September 4, 2019 by Ted Yapo 8 Comments

It’s not uncommon to find us doodling on paper as an aid to thinking, for recreation, or simply because we’re bored. But, this kind of manual labor is so last century. It’s 2019, and we should have robots to fill our notebooks with cross-hatched illustrations. Well, [Alex Weber] is way ahead of us on this account: the outstanding SCARA drawbot he created can be unleashed to draw all manner of things at his command.

The robot, named Mechpen, and pronounced “McPen”, is of a SCARA (Selective Compliance Assembly Robot Arm) design, with two parallel axes controlling the x-y movement of the arm. Robot design is always a series of trade-offs; in this case, [Alex] has sacrificed some accuracy to achieve a long reach. Two NEMA 23 stepper motors reside in the base, along with all the electronics. This makes the base a heavy 15 kg, which is good as it helps stabilize the arm during movement. The arm uses a mix of off-the-shelf and custom hardware, most of which is dotted with holes drilled to reduce the mass of the moving parts. Two 700 mm sections of the arm made from carbon fiber tubes give the drawbot a 140 cm reach — long enough to fill an A0 paper with its beautiful mechanical doodling.

The brains behind the arm are two-tiered. An Einsy RAMBo board, designed for 3D printers, controls the stepper motors. Above that, a Raspberry Pi runs Octoprint to control the ‘bot. This choice turned out to be very convenient for working around a mechanical issue: the elbow flexes too far in the Z-axis. The difference in pen height between the elbow at 90 vs 180 degrees was 20-25 mm; too much to fix with just a spring-loaded pen. The solution: use a bed-leveling algorithm designed for 3D printers. A VL6180X distance sensor measures the distance to the paper over a number of grid points, then the software moves the servo up and down accordingly while drawing to keep the pen on the paper.

Some custom-written software converts SVG graphic files to gcode suitable for printing, allows selection of different stroke and fill types, and separation of different colors into individual gcode files to be plotted with different pens.

Definitely check out the video of Mechpen in action, after the break.

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