Human brains evolved to pay extra attention to anything that resembles a face. (Scientific term: “facial pareidolia”) [Rongzhong Li] built a robot sensor array with multiple emitters and receivers augmenting a Raspberry Pi camera in the center. When he looked at his sensor array, he saw the face of a cat looking back at him. This started his years-long Petoi OpenCat project to build a feline-inspired body to go with the face.

While the name of the project signals [Rhongzhong]’s eventual intention, he has yet to release project details to the open-source community. But by reading his project page and scrutinizing his YouTube videos (a recent one is embedded below) we can decipher some details. Motion comes via hobby remote-control servos orchestrated by an Arduino. Higher-level functions such as awareness of environment and Alexa integration are handled by a Raspberry Pi 3.

The secret (for now) sauce are the mechanical parts that tie them all together. From impact-absorption spring integrated into the upper leg to how its wrists/ankles articulate. [Rongzhong] believes the current iteration is far too difficult to build and he wants to simplify construction before release. And while we don’t have much information on the software, the sensor array that started it all implies some level of sensor fusion capabilities.

We’ve seen lots of robotic pets, and for some reason there have been far more robotic dogs than cats. Inspiration can come from Boston Dynamics, from Dr. Who, or from… Halloween? We think the lack of cat representation is a missed opportunity for robotic pets. After all, if a robot cat’s voice recognition module fails and a command is ignored… that’s not a bug, it’s a feature of being a cat.

[via TheNextWeb]

Here at Hackaday we are big fans of the TV show, “How It’s Made”. It’s not much of a stretch to assume that, as somebody who is currently reading this site, you’ve probably seen it yourself. While it’s always interesting to see the behind the scenes process to create everyday products, one of the most fascinating aspects of the show is seeing how hard it is to make things. Seriously, it’s enough to make you wonder how companies are turning a profit on some of these products when you see just how much technology and manual work is required to produce them.

That’s precisely the feeling we got when browsing through this absolutely incredible overview of how [HDC3] makes his maple syrup. If that’s not a sentence you ever thought you’d see on Hackaday, you aren’t alone. But this isn’t a rusty old pail hanging off of a tap, this is a high-tech automated system that’s capable of draining 100’s of gallons of sap from whole groves of trees. We’ll never look at a bottle of syrup in the store the same away again.

It all starts with hundreds of tiny taps that are drilled into the trees and connected to a network of flexible hoses. The plumbing arrangement is so complex that, in certain, areas high tension support wires are necessary to hold up the weight of the hoses and their sweet contents. The main hose leads to an Arduino-powered collection station which maintains a 100 kPa (29 inHg) vacuum throughout the entire system.

The sap is temporarily held in a 250 gallon container, but at this point it’s still just that: sap. It needs to be refined into something suitable for putting on your pancakes. The first step of that process utilizes a reverse osmosis filtration system to pull the water out of the sap and increase its sugar concentration. [HDC3] says the filtration system is built from eBay scores and parts from the home improvement store, and it certainly looks the part of something that would be under a kitchen sink. This system is able to increase the sugar concentration of the sap from around 2% as it comes out of the trees to 8%. But it’s still a far way off from being ready to use.

Interestingly enough, the last steps of the process are about as old-school as they come. The semi-concentrated sap is placed in a long low metal pan, and heated over a wood fire to drive off more of the water. This process continues until the sap is roughly 60% sugar, at which point it is filtered and moved into the house to finish boiling on the stove.

All told, the syrup is boiled for eight hours to bring its sugar content up to 66%. Even with the improvements [HDC3] has made to the system, he reveals that all this hard work only results in slightly more than a half-gallon of final syrup. Talk about dedication.

It probably comes as no surprise that this is the first time Hackaday has ever run a story about producing maple syrup. However we’ve seen a number of automated beer brewing systems that seem to have been tackled with similar zeal. There’s probably a conclusion to be drawn there about the average hacker’s diet, but that’s a bit outside our wheelhouse.

[via /r/DIY]

Vadim Panov wanted a way to automatically restart a PC that was simple and cheap to make.

For this task, he turned to an Uno due to its wide availability; however, any Arduino board with at least one digital I/O pin and a USB-enabled serial port will work.

The device sends a “hello” string to the PC, to which it expects a “HELLO” back from the PC—running its own corresponding Java program—within 10 seconds. If it doesn’t receive this string, it assumes that the computer is frozen, and uses a reed relay to trigger the motherboard reset pin.

Panov’s idea could be used to monitor and reset cryptocurrency rigs, but could be adapted to other PC setups as needed.

Here’s how it works: the PC-side program tries to connect to every single serial port in your system within a period of 30 seconds (including the ports that appear during this process). To each port it’ll send the handshake string “hello” and monitor the input, expecting to receive uppercase “HELLO” back. When the handshake is finished, it’ll send ping strings once each five seconds.

The watchdog program on Arduino scans the input for “ping” strings. If no such string has been received within 10 second period, the watchdog will forcibly restart your PC.

Therefore, this scenario where you manually run it will be “one-off”, i.e. once the PC has been restarted, the watchdog will be stuck in the pre-handshake state. To make it work all the time, add the Java program to the startup list of your operating system of choice.

You can read more here and check it out in action below!

For a class assignment, Matt Robb along with teammates Kara and Andrew needed to make a project using an Arduino and various other components. What they came up with was a carnival-style game that uses a stepper motor to rotate three targets containing IR sensors out of a nicely-painted cardboard box.

An Arduino Uno provides control for the game. When hit with a signal from an IR remote, an LED on the target goes out, a buzzer beeps, and it momentarily stops spinning.

It looks like it was a lot of fun to build and play, so be sure to check it out in the video seen here!

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3/6/18- Just finished the front legs! Woohoo! I did several test runs on one of them, the most recent being documented in the video. But I screwed up the movement range in the test Arduino sketches, since the servos can no longer rotate fully. I hope I didn’t strain the servo too bad...

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Some dogs have no sense of self-preservation. Given the opportunity, they will eat until they’re sick. It’s up to us humans to both feed them and remember doing it so they aren’t accidentally overfed. In a busy household with young children, the tricky part is the remembering.

[Bryan]’s family feeds their dog Chloe once a day, in the mornings. She was a rescue who spent a few years scrounging for meals on the street, so some part of her is always interested in finding food, even if she just ate. Each morning, the flurry of activity throughout the house is compounded by Chloe’s repeated requests for food, so [Bryan] got his kids involved and built a simple circuit that lets everyone know—at a glance—whether Chloe was fed.

Chloe’s kibble is kept in a touch-top wastebasket that flips open at the press of a button. [Bryan]’s dog-fed detector uses a reed switch and an Arduino clone to detect when the lid is opened. When the reed switch goes, low, the Arduino lights up an LED. The light stays on for two hours and then shuts off automatically to get ready for the next day. You don’t have to beg for a demo video, because it’s waiting for you after the break.

Since Chloe devours a bowl of food in about two minutes flat, maybe the next project for [Bryan]’s family could teach her to slow down a bit.

When dealing with robotics and other electronics projects, it can be important to know how many revolutions a motor is making. From here, you can infer the distance that your device has traveled, or any number of other important variables.

If you’d like to get started with this type of sensing, this electronoobs tutorial will show you how to get things hooked up using an Arduino and a computer, along with an oscilloscope to verify measurements up to 10,000 RPM.

In his setup, an IR emitter/receiver bounces light off a spinning object. When light reflects back, it opens the circuit, causing the output to be grounded via a pulldown resistor, telling you that a revolution has been made. The 3D-printed device also features an OLED screen.

To emit infrared light we need a IR LED and to detect it a IR sensible transistor. Usually you could find those as a one unique module. To amplify the signal I’ve used the LM324 amplifier. You will also need a 100 ohm resistor and a 4.7k ohm one. To supply the system we will need a basic 9V battery and connector, an Arduino Nano, and an OLED screen. The case is 3D printed…

You can find more details on the build process here, as well as a demo of the tachometer below!

Tired of cleaning your house? A robotic vacuum may be the logical solution, but if you’re “theking3737” something off-the-shelf just isn’t quite cool enough. Created as part of a school project, he was responsible for the hardware design, while a fellow classmate took care of the programming.

The DIY device uses an array of what appear to be ultrasonic sensors for navigation, and an Arduino Mega as the brains. It also features an HC-05 Bluetooth module that enables it to be controlled via an Android phone or smartwatch. All the electronics are housed inside a 3D-printed closure.

Impressively, the team had “never done anything like this before,” and the results look great—encouragement for anyone hesitant to start on a project because of inexperience!

What kind of TV do you have? An older 720p model, or the now standard 1080p? Perhaps you’ve made the leap to the next generation, and are rocking a 4K display in the living room. All those are are fine and dandy if you just want to watch the local sportball contest, but where’s the challenge in that? With all the technology and modular components we have access to anymore, nowadays all the real hackers are making their own TVs.

Of course, when [Nikolai] built his very own LED TV, he did have to make a few concessions. For one thing, there’s no tuner on this model. Oh, and there’s the small issue of only having a 16×16 resolution. It might not be your idea of the perfect display, but it’s just perfect for his newborn son.

That’s right, [Nikolai] got his entry for the “Hacker Parent of the Year” award in early, and built an LED display for his son that he’s calling “BabyTV”.

Rather than the shows, trash, advertisements that they play on the kid channels, this TV only shows animated characters from retro games. We’ll concede that this project might be an elaborate Clockwork Orange style attempt at hypnotizing his son to instill an appreciation for classic gaming. But we’ll allow it.

To make his BabyTV go, [Nikolai] used a 16×16 WS2812B LED panel and an Arduino Nano. Two rotary encoders are used to allow adjusting brightness and change the character currently being shown on the screen. As a particularly clever hack, the Arduino has an IR sensor attached and is constantly watching for any signals. If an IR signal is detected, the BabyTV switches to the next image. So if Junior has a standard IR remote in his hands, any button he presses will cause the display to change to the next “channel”.

Historically speaking we haven’t seen much stuff for children here at Hackaday, but 2018 seems to be changing that. Recent projects like the incredible scratch built mini excavator and gorgeous AT-ST high chair would seem to indicate we’re currently witnessing a generation of hackers become parents. Don’t panic folks, but we might be getting old.

It is getting difficult to find a desktop or laptop computer with only a single CPU. Even a typical ARM-based computer now probably has multiple cores. Of course, there’s nothing to stop you from using multiple microcontrollers — like the Arduino — together. To make the process neater, [Dimitris Platis] put together Moltoduino, essentially an Arduino on a shield made to plug into another Arduino. And, yes, they will stack. You can see a video about the open source boards, below.

The key is how the board brings the pins out to connections that are easy to jumper between boards. There are several obvious use cases, but one that [Dimitris] is particularly interested in is hardware-in-the-loop testing. The idea is that you can use a simulated I/O device in one computer to exchange fake data with the software under test.

For example, you might be working on a sous vide cooker that reads a temperature and controls a heater. A second computer could stand in for the temperature sensor and heater. You could log outputs and also control the inputs. This is really nice when you want to set up repeatable test cases.

Of course, you don’t have to stack the boards to make that work. In fact, you don’t have to use another Arduino. A PC or some other controller could be the surrogate test device. But having it all in a stack is handy. There are several examples of doing testing using simulated hardware on the project’s GitHub page. The test subjects are a robot car and an ultrasonic device.

One neat feature is that each board has a switch to enable the master Arduino to ISP program it. So while you might not need to stack boards to use any of the proposed techniques, it does make for a nice and compact package.

Usually, when we see a cluster it uses Raspberry Pis. Or, sometimes, PCs.