Automatic Naptime With BabyBjorn Bouncing Servo

Any parent with a baby and deep pockets– or friends with deep pockets– will probably sing the praises of the BabyBjorn rocking sling chair. A simple spring-loaded sling seat allows you to rock a child to sleep like magic– but you do have to rock the child. In the tradition of fathers everywhere since the stone age, [Ceyhun Karataş] saw that as something to tinker around, creating his Automatic BabyBjorn Bouncer/Rocker with a servo, an Arduino, and some 3D printed parts.

You still can’t leave your child unattended with this hack, [Ceyhun] takes pains to point out, but it will free a hand so you can keep junior happy while tinkering up other toys for him or her. Music players are a popular staple, for example.

You should have plenty of time for such projects, because it won’t take long for you to replicate [Ceyhun]’s invention– it’s only as complicated as it needs to be, which is not very. The servo, a Futaba S3003 which is mounted to the bottom of the rocker in a 3D printed case, reels the baby in with a string tied to the bouncing seat portion.  The BabyBjorn’s built-in spring bounces junior back up. As stated, Arduino Nano controls the servo, with two potentiometers in the build allowing you to control the speed and amplitude of the bounce independently to get the perfect naptime ratio. Everything you need to get started — aside from the hardware and the child– is available at the link above. You can see it in action in the video below, which in spite what you may fear from the Turkish thumbnail, does have authentic English audio, not AI auto-dubbing.

If you’ve got the baby but not the bouncy chair, have a gander at this mechatronic crib that does something similar on a much larger budget.

Thanks to [Ceyhun] for overcoming the new-parent sleep deprivation to document this project and send in a tip.

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Snooping Flume Water Monitor Data On The Wire

[Stephen] had an interesting piece of hardware at home—namely, a Flume water monitor. It’s a smart device which reports usage data to Flume’s servers, and the water utility in turn. He’d previously determined how the device worked mechanically to monitor water flow, but he had a greater goal—figuring out how to sniff the reported data as it passed through his network on its way to Flume servers.

The Flume rig has a sensor installed in the water line, which communicates to a bridge device that then hooks up to the Internet. [Stephen] had an early win, figuring out how to trick the bridge unit of the Flume water sensor into sending data in plaintext. This was as simple as corrupting the public key in the device’s flash. However, this wasn’t a perfect solution—as the corrupt key stopped the device from authenticating with Flume’s servers. Further diving into the LibHydrogen encryption implementation, however, revealed that the device was apparently authenticating without using session keys, relying only on a static device secret key which can be harvested from the onboard flash. This allowed [Stephen] to build a tool to sit in between the bridge and the Flume servers, forwarding traffic seamlessly while decrypting and saving it locally at the same time.

With this setup, [Stephen] was able to locally log water flow and status data from the sensor. It does come with a caveat, that the man-in-the-middle setup could block the hardware from receiving firmware updates in future. It’s also worth checking out [Stephen’s] earlier work on demystifying the Flume hardware, too. The relay tool is available on GitHub for the curious.

We love seeing hackers figure out how to interface utility meters and similar devices, in legal and appropriate manners, of course. If you’re tinkering in this realm yourself, feel free to let us know on the tipsline!

Bridging Older Tasmota Hardware Into Apple Home

The Tasmota firmware is a popular choice for flashing to a range of Espressif microcontrollers to turn them into smart home devices. If you have such devices in your house, you might wish they were easier to integrate with the Apple Home platform. As it turns out, though, there’s a convenient app for that.

[Christof Müller] built an app called Tasmoshelf for just this purpose. Its primary claim to fame is that it can easily help port a Tasmota-based setup into the Apple Home universe. It can achieve this without requiring a Home Assistant server or MQTT broker or any other workarounds. This is thanks to the fact that Apple Home is compatible with Matter technology, as are ESP32 devices running Tasmota 13 firmware or newer. They can natively jump on an Apple Home setup, and even act as a bridge for older ESP8266 devices that can’t speak Matter themselves. The device is able to run network scans to automatically discover devices and advise whether they can hook up directly to Apple Home, or whether a bridge is needed.

If you’re running Tasmota devices and want to easily integrate them, you might find Tasmoshelf a useful addition to your smart home setup. Just note that it does require a one-off purchase if you intend to use it beyond three devices, a limit which some might find somewhat restrictive.

We’ve looked at Tasmota in detail before; it’s a great way to whip up a smart home to suit your own desires. Meanwhile, if you’re whipping up your own nifty integrations, don’t hesitate to let us know on the tipsline.

Titanic-esqe Telegraph Keeps Relationship Afloat

When people say the key to a happy, long-lasting marriage is communication, they generally mean the verbal kind: talking things out with your spouse, sharing your feelings, and all that lot. [Rich] AKA [Thumblegudget] took it another way, and built a engine-room telegraph for intramarital communication.

Now, this is less crazy than it sounds. Like the ship’s telegraph, which matched the position of an indicator on the bridge and in the engine room, [Rich]’ telegraph pairs an indicator in his office with one in the living areas of the house. He sets himself to “busy” and the arrow on the matching unit in the basement moves to that position. This naturally goes both ways, which allows his wife to point the needle to remind [Rich] that it may be time for hugs, dinner, or — most essentially for a brit — tea.

In operation each unit has a gimbal motor paired to a rotation sensor and an ESP32-S3 driving it. Thanks to that rotation sensor, the gimbal motor is programmed to lock itself into the positions on the wheel when you poke it, and the ESP32 wirelessly synchronizes the two units. A moving arrow might not be enough to get [Rich] to come down to dinner, so just like the ship’s telegraph you may remember from Titanic, [Rich]’s comes equipped with a bell to draw attention to itself.

Given [Rich]’s wife participated in the video and isn’t filing for divorce, it seems he may be onto something. Perhaps good communication doesn’t need to involve cumbersome human speech at all; maybe all a marriage needs is a telegraph like this and some paddles to send more complicated messages via Morse code.

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The countertop in its natrual habitat: a van.

Cotton-Fiberglass Composite Makes Lightweight RV Countertops

You’ve seen fiber-reinforced-plastic before, no doubt, but perhaps never quite like in this video by [Whitburn Studio]: it’s still got the usual resin, but instead of glass or carbon fibers, he’s using printed Japanese cotton to create strong, lightweight and good looking parts for the interior of his RV– specifically the countertops.

The technique is very similar to the sort of moldless composite work Burt Rutan pioneered in aircraft use. The fiber-reinforced plastic is formed around a positive ‘buck’ that remains inside the final part, adding stiffness and some backing. Unlike Rutan’s designs, which used pure Styrofoam inside, [Whitburn] is using a sandwhich of two layers of thin ply (3.6 mm) with XPS foam in between. Adding plywood means you don’t need many layers of fiber– again, that’s a decorative cotton, here– to get a surface that won’t dent into the styrofoam when you drop a coffee cup on it.

Indeed, with the plywood providing much of the strength, he’s only using a single layer of cotton and a second of fiberglass– though the glass fibers are really there to protect the pretty print from oopsies while sanding, rather than for their mechanical properties, by the sounds of it. Everything is held together with clear epoxy resin, which also fills the weave of the fabrics. Multiple coats of that are required to get the smooth, shiny surface he shows off at the end, but all that sanding and buffing really pays off. That’s also where you have to be really careful to avoid oopsies– go through the cotton and you have to start over.

Aside from the aesthetics, since this is going in a vehicle the weight is an important consideration– the bigger of the two counters he makes, pictured here, weighs in at only 2.4 kg or 5.2 lb including the cutout covering the sink. That’s pretty good all things considered– a lot lighter than a cement countertop, or even one made of DIY resin tiles.

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An Automated Water Tank Controller

[Jumpor] lives in a part of India where the water infrastructure is a little frustrating to use. Water gets delivered to underground tanks outside of homes, and must then be regularly pumped into rooftop tanks prior to use inside the building. Typically, this pumping is handled manually—by switching on a pump and running it until water comes out of an overflow pipe to indicate the rooftop tank is full. [Jumpor] decided to improve this wasteful and time consuming process with a little automation project.

The build is based around an ESP32 microcontroller. It’s hooked up to an ultrasonic sensor which can measure the water level inside the rooftop water tank. When the sensor detects the level descending below a set point, the microcontroller fires a relay to trigger the lift pump to fill up the tank. Once the sensor detects the tank is full, the pump is shut off, saving liters of water compared to waiting for water to pour out of the overflow as an indicator of the same.

It’s a simple enough project, but [Jumpor] was sure to include the important practical considerations. Since the rig was being installed in a rental, it was desirable to not make any permanent modifications to the water system. Thus, a fresh cap for the water tank was modified to host the electronics and level sensor, such that the original could be replaced at a later date. Due consideration was also paid to things like avoiding crossing the minimum detection threshold of the sensor, which could lead to accidental overflows if not managed correctly.

The aim of this project was to ease the day to day burden of maintaining a basic utility. That’s the sort of project we love to see around these parts.

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A Complex Way To Push A Button

We’ve likely all looked at a simple problem in our lives and thought that it would be an easy fix, only to realize that the project is enormously more complicated than we first realized. Whether that’s starting a home improvement project, doing a quick repair to a bicycle or car, or trying to install an obscure piece of software on a Linux machine, the amount of time we budget for these tasks often ends up woefully underestimated. []’s night light needs to have its brightness set every night, and it seems easy enough to get a microcontroller to automate that, right?

Well, upon opening the small device, the first issue is that there is no labeling on any of the parts, so simply adding a jumper on to existing microcontroller pins without damaging anything wouldn’t easily be possible. Adding a secondary microcontroller is the next logical step, but the power supply in the night light is extremely underpowered so using even the smallest Raspberry Pi or off-the-shelf Arduino was out of the question too. [Oscar] instead chose an ATtiny85, which solves the power requirement issue, but these are a bit more of a challenge to program without a USB device. From there, it needs a transistor wired in to the circuit to actually push the button for him, plus a few support resistors, so [Oscar] actually had a PCB custom-built to hold all of these components.

Even after all of that, the space within the night light enclosure made installing the PCB a challenge, but in the end he has a device which, when his home automation system powers on the plug for the nightlight, automatically boots up and pushes the switch the required number of times and then puts itself to sleep. We’d call that a success even after the colossal effort getting this inexpensive, small light working the way he wanted. There are some other low-powered solutions for problems like these too, as long as being battery-powered isn’t a dealbreaker.