The Design Process For A Tiny Robot Brain

October 20, 2024 by Bryan Cockfield 13 Comments

As things get smaller, we can fit more processing power into devices like robots to allow them to do more things or interact with their environment in new ways. If not, we can at least build them for less cost. But the design process can get exponentially more complicated when miniaturizing things. [Carl] wanted to build the smallest 9-axis robotic microcontroller with as many features as possible, and went through a number of design iterations to finally get to this extremely small robotics platform.

Although there are smaller wireless-enabled microcontrollers, [Carl] based this project around the popular ESP32 platform to allow it to be usable by a wider range of people. With that module taking up most of the top side of the PCB, he turned to the bottom to add the rest of the components for the platform. The first thing to add was a power management circuit, and after one iteration he settled on a circuit which can provide the board power from a battery or a USB cable, while also managing the battery’s charge. As for sensors, it has a light sensor and an optional 9-axis motion sensor, allowing for gesture sensing, proximity detection, and motion tracking.

Of course there were some compromises in this design to minimize the footprint, like placing the antenna near the USB-C charger and sacrificing some processing power compared to other development boards like the STM-32. But for the size and cost of components it’s hard to get so many features in such a small package. [Carl] is using it to build some pretty tiny robots so it suits his needs perfectly. In fact, it’s hard to find anything smaller that isn’t a bristlebot.

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AI Pet Door Rejects Dead Mice

January 9, 2024 by Kristina Panos 32 Comments

If you have pet with a little access door to the outside world, and that pet happens to be a cat, you’re likely on the receiving end of all kinds of lifeless little lagniappes. Don’t worry, it’s CES season out in Las Vegas and a company called Flappie has the solution — an AI-powered cat door that rejects dead mice and other would-be offerings.

It works about like you might expect — there’s a motion sensor and a night-vision camera on the exterior side of the door. Using Flappie’s “unique and proprietary” dataset, the door distinguishes between Tom and Jerry and keeps out unwanted guests with more than 90% accuracy. To do this, Flappie collected video of a lot of cats and prey in a variety of lighting conditions. There’s even a chip detection system that will reject all other cats.

Thankfully, it’s not all automation. The prey detection system can be turned off entirely, and there are manual switches on the inside for locking and unlocking the door at will. You don’t even have to hook it up to the Internet, it seems.

Americans will have to wait a while, as the company is rolling out the door in Switzerland and Germany first. No word on when the US launch will take place, but interested parties can expect to pay around $399.

Of course, this problem can be solved without AI as long as you’re willing to review the situation and unlock the door yourself.

Quivering Facehugger Is All Geared Up

December 30, 2023 by Donald Papp 4 Comments

[Jason Winfield] shared with us a video describing a project with a lot of personality: a mounted, lit, and quivering Alien facehugger triggered by motion. The end result is a delightful jump scare, and the Raspberry Pi that controls everything also captures people’s reactions.

It starts with a little twitch when motion is sensed, then launches into a perfectly unsettling quiver combined with light and sound. We particularly like the wave-like effect from the LED lighting, which calls to mind illumination from rotating hazard beacons.

The unit looks like a mounted and tastefully-lit static model, but is actually primed to sense motion.

One challenge was how to efficiently move the legs. Rather than use a motor for each limb, [Jason] settled on a single motor driving a rotating cam arrangement. You can see the results for yourself in the video below, but getting there was not simple.

The surplus motor [Jason] chose is thin and high-torque, but runs extremely fast. Since he wanted the legs to quiver creepily rather than vibrate, something needed to be done to mitigate this.

The solution is a planetary gear assembly that drives a rotating ring and cam arrangement coupled to the facehugger’s legs. There’s only one motor, but the effect is that each leg’s motion is independent of the others. The whole assembly is quite slim, and everything is contained within the frame.

Facehuggers and gear assemblies are not exactly an everyday combination, but believe it or not this isn’t the first time the two have joined forces. Check out the Aliens-themed cuckoo clock, complete with crew member torso and emerging chestburster!

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Motion-Activated Clock Only Lights Up On Command

December 16, 2022 by Lewin Day 8 Comments

While some of us can fall asleep anywhere from a noisy auditorium to a brightly lit train station, others are more fussy, requiring quiet and dark to nod off. [Craig Lindley] likes to minimize light when he’s trying to sleep, and decided to build himself a simple clock that wouldn’t disturb his rest.

The basic concept was to build a clock that would only display the time on command. In this case, that command would be a wave of a hand in front of the clock. The build is based around a Lilygo ESP32 T-Display unit, which combines the ESP32 with an LCD display and a battery management system. The ESP32’s WiFi connection provides accurate time via querying an NTP server. A passive infrared motion sensor is used to detect the motion of the user’s hand in front of the clock.

While all kinds of clocks and clock radios are available out there, few are motion activated. [Craig]’s work is a great demonstration of building your own solutions to your problems. We’ve seen some other neat motion-sensing convenience hacks before, too!

A Simon toy with a robot that slaps little hands against it

Silicone-Slapping Servos Solve Simon Says

December 6, 2022 by Robin Kearey 7 Comments

Most modern computer games have a clearly-defined end, but many classics like Pac-man and Duck Hunt can go on indefinitely, limited only by technical constraints such as memory size. One would think that the classic electronic memory game Simon should fall into that category too, but with most humans struggling even to reach level 20 it’s hard to be sure. [Michael Schubart] was determined to find out if there was in fact an end to the latest incarnation of Simon and built a robot to help him in his quest.

The Simon Air, as the newest version is known, uses motion sensors to detect hand movements, enabling no-touch gameplay. [Michael] therefore made a system with servo-actuated silicone hands that slap the motion sensors. The tone sequence generated by the game is detected by light-dependent resistors that sense which of the segments lights up; a Raspberry Pi keeps track of the sequence and replays it by driving the servos.

We won’t spoil the ending, but [Michael] did find an answer to his question. An earlier version of the game was already examined with the help of an Arduino, although it apparently wasn’t fast enough to drive the game to its limits. If you think Simon can be improved you can always roll your own, whether from scratch or by hacking an existing toy.

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ESP32-Cam Makes A Dandy Motion Detector

October 23, 2021 by Al Williams 7 Comments

Halloween is right around the corner and just about every Halloween project needs some kind of motion sensor. Historically, we’ve used IR and ultrasonic sensors but [Makers Mashup] decided to use an ESP32-Cam as a motion sensor in his latest animatronic creation. You can see a video of the device and how it works below.

The project is a skull that follows you around with a few degrees of motion on a stepper motor. There’s a 3D-printed enclosure to make the hardware assembly easy. The base software was borrowed from [Eloquent Arduino].

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Useless Box With Attitude Isn’t Entirely Useless

November 3, 2020 by Kristina Panos 3 Comments

What is it about useless machines that makes them so attractive to build? After all, they’re meant to be low-key enraging. At this point, the name of the game is more about giving that faceless enemy inside the machine a personality more than anything else. How about making it more of a bully with laughter and teasing? That’s the idea behind [alexpikkert]’s useless machine with attitude — every time you flip a switch, the creature of uselessness inside gets a little more annoyed.

In this case the creature is Arduino-based and features two sound boards that hold the giggles and other sounds. There are three servos total: one for each of the two switch-flipping fingers, and a third that flaps the box lid at you. This build is wide open, and [alexpikkert] even explains how to repurpose a key holder box for the enclosure. Check out the demo after the break.

We love a good useless machine around here, especially when they take a new tack. This one looks like any other useless machine, but what’s happening inside may surprise you.

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