Get Quarantine Fit With This Smart Pull-up Bar

May 4, 2020 by Tom Nardi 16 Comments

Most gyms are closed right now due to social distancing rules, which is what we’re using as our latest excuse to justify our sloth-like lifestyle. But apparently some people miss working out enough that they’re putting together impromptu home gyms. [Michael Pick] has even outfitted his DIY pull-up station with an Arduino to keep track of his exercise while on lockdown. You may not like it, but this is what peak performance looks like.

In the video after the break, [Michael] explains the design and construction of the bar itself which technically could be thought of as its own project. Obviously the Arduino counter isn’t strictly necessary, so if you just wanted to know how to put some scraps of wood and suitably beefy rod together in such a way that it won’t rip off the wall when you put your weight on it, this video is for you.

Towards the end of the video, he gets into an explanation of the electronic side of the project. Inside the 3D printed enclosure is an Arduino Pro Mini, a HC-SR04 ultrasonic sensor, and a 1602 serial LCD. Once the gadget has been mounted in the proper position and activated, it will count how many pull-ups [Michael] has done on the screen.

While we historically haven’t seen a whole lot in the way of homebrew exercise equipment, the current COVID-19 situation does seem to be getting the adrenaline flowing for some of you. We recently covered some DIY dumbbells made from hardware store finds that would be an excellent first project for any hackers who’ve recently been ejected from the Matrix and are trying to use their muscles for the first time.

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Any Remote Can Be A Universal Remote

May 1, 2020 by Jenny List 23 Comments

Everyone has a stack of old infra-red remote controllers lying around, for devices that have long since shuffled off this mortal coil. Containing little more than an application-specific encoder chip, keyboard, and IR LED, they’re of little use unless you happen to have another device that uses the same encoding scheme. For [RiYa] though they represent an opportunity, to be repurposed into controllers for other devices. How? Hijack the bitstream with an ATtiny13 microcontroller, re-encode it, and send it out afresh into the ether from the LED. It’s a gloriously simple solution which we can’t help applauding, and has the potential to cheaply replace all those universal remotes.

The ATtiny itself along with a buffer to drive the LED is mounted on a small breakout board and concealed within the shell of the remote. We don’t learn much about the power supply arrangement, but we’d expect the ATtiny to be on its most power-sipping behaviour as anything which would shorten the battery life of a remote would be unlikely to be popular with a couch potato forced to change AA cells every few weeks. There’s a plan for a learning mode to make it more like a commercial universal remote, but for now the translation is hard coded.

Of course, should you lack a handy old remote to play with, you can always try a smartphone.

Roll Your Own Automation With ESPHome

April 20, 2020 by Donald Papp 17 Comments

There are several different paths to a smart home, and [Marcus] eventually settled on using ESPHome and ESP8266/ESP32 based devices to create a complete DIY smart home solution which covers his garage door, sprinklers, LED strips, light bulbs, and outlets. There’s even an experimental (and very economical) ESP32-CAM based camera, shown here.

In fact, [Marcus]’s write-up could double as a sort of reference design. If you’re curious about ESPHome, be sure to read what he has to say because he explains exactly how he configured each device and any challenges he encountered in the process.

Beyond the software guidance, the post is also a great resource on how to flash a new firmware onto several different smart devices. [Marcus] provides nicely labeled images of the boards that show where you need to connect your programmer, which just might save you some trouble down the line. Though he did manage to set fire to one of the bulbs, so keep an eye out for that.

Tasmota is another open source option for controlling ESP8266-based devices, and if you’d like to explore that direction don’t forget that flashing Sonoff devices with Tasmota firmware recently got much, much easier.

A Gambler’s Bottle Opener

April 9, 2020 by Moritz v. Sivers 12 Comments

People can certainly become creative when it comes to completing simple tasks like that of removing a bottle cap. Woodworker [Matt Thompson] has come up with a next-level bottle opener that not only does the job but also functions as a game of chance. (Video, embedded below.)

The process usually starts with a spin of his chore wheel that will surprisingly often advise you to drink a beer. While the bottle cap is removed by a standard wall-mounted opener, the fun starts when the cap falls through a wooden labyrinth of various mechanisms reminiscent of a Rube Goldberg machine. Finally, the cap goes through an arrangement of nails, known as a Galton Board which is also found in some pinball and historic gaming machines, before landing in one of two containers marked “winner” and “try again”. The former will trigger the rotating wheel of a self-built peanut dispenser to provide the thirsty person with some tasty snacks. While we would love to see a making-of video with more technical details of this project, we still appreciate the exquisite woodworking and fine craftsmanship that went into building it.

By the way, if you are ever in need of an Arduino board that can also serve as a bottle opener then have a look at HaDuino.

[Thanks to Emanuel for pointing out the proper name of the Galton Board]

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R/C Toilet Paper Roll Is The Hero We Deserve

April 4, 2020 by Tom Nardi 11 Comments

For reasons that most rational consumers can’t fathom, a not inconsiderable segment of the population believes the key to their continued survival during a pandemic unprecedented in modern times is to stockpile toilet paper. This leaves those of us not compelled to act based on the whims of our bowels looking at bare racks in the paper product aisle more often than not.

Which makes it the perfect time for [Ariel Yahni] to develop his remote controlled toilet paper roll. With this gadget deployed, you just might have a chance at drawing the Karens away from all the rolled gold long enough to grab yourself a pack. Even if it doesn’t distract the other ~~competitors~~ shoppers, you can at least enjoy the looks on their faces as it scurries by.

The project starts with, of all things, popsicle sticks. These are used to make a reinforced platform to which the two motors, radio receiver, speed controller, and battery are mounted. With some clever packing, [Ariel] is able to (tightly) fit it inside of a cardboard tube with just the bottoms of the two wheels protruding through cutouts. A careful wrapping with toilet paper is then used to give it the look of a partially used roll, including a trailing “tail” that flutters in its wake.

In the video after the break, you can see [Ariel] take his roll of motorized TP through a local mall for a test drive. We’re sorry to say that nobody appears to make a wild dive for it during the test. But that could be because the video was recorded back in December before people had resorted to fighting over toiletries. It also explains why he was able to get into a mall in the first place.

Just think, if we had embraced the high-tech toilets of the future back when we had a chance, we could have avoided this whole thing. As far as dystopias go, this one is shaping up to be pretty weird.

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DIY ESP32 Alarm System Leverages 433 MHz Sensors

April 2, 2020 by Tom Nardi 14 Comments

There’s a huge market for 433 MHz alarm system hardware out there, from PIR motion detectors to door and window sensors. If you want to put them to work, all you need is a receiver, a network-enabled microcontroller, and some code. In his latest video, [Aaron Christophel] shows how easy it can be.

In essence, you connect a common 433 MHz receiver module to an ESP32 or ESP8266 microcontroller, and have it wait until a specific device squawks out. From there, the code on the ESP can fire off using whatever API works for your purposes. In this case [Aaron] is using the Telegram API to send out messages that will pop up with a notification on his phone when a door or window is opened. But you could just as easily use something like MQTT, or if you want to go old-school, have it toggle a relay hooked up to a loud siren.

Even if you aren’t looking to make your own makeshift alarm system, the code and video after the break are a great example to follow if you want to get started with 433 MHz hardware. Specifically, [Aaron] walks the viewer through the process of scanning for new 433 MHz devices and adding their unique IDs to the list the code will listen out for. If you ever wondered how quickly you could get up and running with this stuff, now you’ve got your answer.

In the past we’ve seen the Raspberry Pi fill in as an RF to WiFi gateway for these type of sensors, as well as projects that pulled them all together into a complete home automation system on the cheap.

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Accurate Dispensing Of Toilet Paper Will Get Us Through The Crisis

April 1, 2020 by Jenny List 51 Comments

As we enter our second week of official COVID-19-related lockdown where this is being written, it’s evident that there are some resources we will have to conserve to help get us through all this. Instead of just using all of something because we can nip out to the store and buy more, we have to look at what we’ve got and treat it as though it will have to get us through the next three months. It’s not always certain that on our infrequent trips to the supermarket they’ll have stocks of what we want.

This is the very last of the toilet paper in my local supermarket, on the 8th of March.

A particular shortage has been of toilet paper. The news was full of footage showing people fighting for the last twelve-pack, and since early last month there has been none to be had for love nor money. To conserve stocks and save us from the desperate measures of having to cut the Daily Mail into squares and hang them on the wall, a technical solution is required. To this end I’ve created a computerised toilet roll dispenser which carefully controls the quantity of the precious sanitary product, in the hope of curbing its consumption to see us through the crisis.

In the midst of a full lockdown it’s difficult to secure immediate delivery of our usual maker essentials, so rather than send off for the controller boards I might have liked it has been necessary to make do with what I had. In the end I selected an older single board computer I had in a box under my bench. The Sinclair ZX81 has a single-core Z80 processor running at 3.25 MHz, dual-channel memory, a Ferranti GPU, and plenty of expansion possibilities from its black plastic case. I chose it because I could repurpose its thermal printer peripheral as a toilet paper printer, and because it has an easily wiped and hygienic membrane keyboard rather than a conventional one that could harbour germs.

Hardware wise I found I was fairly easily able to adapt a standard roll of Cushelle to the ZX printer, and was soon dispensing sheets with the following BASIC code.

10 REM TOILET PAPER PRINTER
20 FOR T=0 TO 44
30 LPRINT ""
40 NEXT T
50 LPRINT "---------- TEAR HERE -----------"

For now it’s working on the bench, but it will soon be mounted with a small portable TV as a monitor on the wall next to the toilet. Dispensing toilet paper will be as simple as typing RUN and hitting the ZX’s NEW LINE key, before watching as a sheet of toilet paper emerges magically from the printer. It’s the little hacks like this one that will be so useful in getting us through the crisis. After all, this Sinclair always has a square to spare.