There’s a Raspberry Pi to fetch the time, the weather, and the Spotify. Old flip clocks invariably tuned in FM radio, so [iz2k] used an RTL-SDR dongle and a software decoder for the deed. This clock even has a big snooze bar, which functions like a night light when there is no alarm actively going off. The three groups of painstakingly-printed flaps are controlled with stepper motors and an IR transmitter/receiver pair to do the counting.
For the interface, [iz2k] kept things nice and simple. The big-knobbed rotary encoder handles volume up/down/mute, and the little one on the front switches between FM radio, Spotify, and silence. Moving either knob generates feedback by flashing LEDs that sit underneath the display. Take a few seconds to flip past the break and check out the short demo.
Like most of us, I sometimes indulge in buying a part for its potential or anticipated utility rather than for a specific project or purpose. That’s exactly how I ended up with the WSX100 Wi-Fi Stepper, a single board device intended to be one of the fastest and easiest ways to get a stepper motor integrated into a project. Mine came from their Crowd Supply campaign, which raised money for production and continues to accept orders.
What’s It For?
The WSX100 Wi-Fi Stepper Driver (with motor), by Good Robotics
The main reason the Wi-Fi Stepper exists is to make getting a stepper motor up and running fast and simple, in a way that doesn’t paint a design into a corner. The device can certainly be used outside of prototyping, but I think one of its best features is the ability to help quickly turn an idea into something physical. When prototyping, it’s always better to spend less time on basic bits like driving motors.
In a way, stepper motors are a bit like RGB LEDs or LCD displays were before integrated drivers and easy interfaces became common for them. Steppers require work (and suitable power supplies) to get up and running, and that effort can be a barrier to getting an idea off the ground. With the Wi-Fi Stepper, a motor can be fired up and given positional commands (or set to a speed and direction) in no time at all. By sending commands over WiFi, there isn’t even the need to wire up any control logic.
At a recent swap meet, [digitalrice] found what appeared to be a like-new QIDI X-Plus 3D printer. It wasn’t clear what was wrong with it, but considering it retails for $900 USD, he figured the asking price of $150 was worth the gamble. As you might expect, the printer ended up being broken. But armed with experience and a supply of spare parts, he was able to get this orphaned machine back up and running.
The first and most obvious problem was that the printer’s Z axis didn’t work properly. When the printer tried to home the axis, one of the motors made a terrible noise and the coupler appeared to be spinning backwards. From his experience with other printers, [digitalrice] knew that the coupler can slip on the shaft, but that didn’t appear to be the case here. Removing the stepper motor and testing it in isolation from the rest of the machine, he was able to determine it needed replacing.
Improving the printer’s filament path.
Unfortunately, the spare steppers he had weren’t actually the right size. Rather than waiting around for the proper one to come in the mail, he took an angle grinder to the stepper’s shaft and cut off the 5 mm needed to make it fit, followed by a few passes with a file to smooth out any burrs. We’re not sure we’d recommend this method of adjustment under normal circumstances, but we can’t argue with the results.
The replaced Z motor got the printer moving, but [digitalrice] wasn’t out of the woods yet. At this point, he noticed that the hotend was hopelessly clogged. Again relying on his previous experience, he was able to disassemble the extruder assembly and free the blob of misshapen PLA, leading to test prints which looked very good.
But success was short lived. After swapping to a different filament, he found it had clogged again. While clearing this second jam, he realized that the printer’s hotend seemed to have a design flaw. The PTFE tube, which is used to guide the filament down into the hotend, didn’t extend far enough out. Right where the tube ended, the filament was getting soft and jamming up the works. With a spare piece of PTFE tube and some manual reshaping, he was able to fashion a new lining which would prevent the filament from softening in this key area; resulting in a more reliable hotend than the printer had originally.
It’s great to see this printer repaired to working condition, especially since it looks like [digitalrice] was able to fix a core design flaw. But a broken 3D printer can also serve as the base for a number of other interesting projects, should you find yourself in a similar situation. For example, replacing the extruder assembly with a digital microscope can yield some very impressive results.
Tofu is a fairly common food in East and Southeast Asian cuisines, but it has also been making its way around vegetarian circles as a meat substitute. While it may be a more environmentally friendly source of protein than meat, it does have the unfortunate side effect of being fairly tedious to cook. To reach the right consistency, tofu requires hours of pressing to drain excess water, which tends to be tedious for most amateur cooks.
A team of students at HackMIT developed a contraption that incrementally presses tofu for you, using signals sent over WiFi to initialize the device. Several 3D-printed components extend an existing food container, along with a stepper motor, motor shield, Adafruit Feather HUZZAH, and a screen.
The motor steps at a rate of 30rpm once a signal is sent from a mobile application, causing four connected threaded rods to begin rotating. The tofu tray travels upwards to press against its lid, draining out excess water. A central gear box containers complementary cutouts that allow the tofu platform to travel vertically when shafts are rotated, pushed by nuts below the platform. The students also included a screen indicating time remaining, as well as a notification sent to the user once the tofu is finished being pressed.
It’s certainly a useful solution that will hopefully increase the popularity of tofu-based recipes!
We often like to say that if something is worth doing, then it’s worth overdoing.This automatic cat feeder built by [krizzli] is a perfect example of the principle. It packs in far more sensors and functions than its simple and sleek outward appearance might suggest, to the point that we think this build might just set the standard for future projects.
The defining feature of the project is a load cell located under the bowl, which allows the device to accurately measure out how much feed is being dispensed by weight. This allows the feeder to do things such as detect jams or send an alert once it runs out of food, as well as easily adjust how much is dispensed according to the animal’s dietary needs. To prevent any curious paws from getting into the machine while it’s doling out the food, the lid will automatically open and close during the filling process, complete with optical sensors to confirm that it moved as expected.
All of the major components of the feeder were printed out on a Prusa i3 MK3S, and [krizzli] says that the feed hopper can be scaled vertically if necessary. Though at the current size, it’s already packing around a week’s worth of food. Of course, this does depend on the particular feline you’re dealing with.
In terms of electronics, the feeder’s primary control comes from an ESP8266 (specifically, the Wemos D1 Mini), though [krizzli] also has a Arduino Pro Mini onboard so there’s a few more GPIO pins to play with. The food is dispensed with a NEMA 17, and a 28-BYJ48 stepper is in charge of moving the lid. A small OLED on the side of the feeder gives some basic information like the time until the next feeding and the dispensed weight, but there’s also a simple API that lets you talk to the device over the network. Being online also means the feeder can pull the time from NTP, so kitty’s mealtime will always be on the dot.
Over the years we’ve seen an incredible array of automatic cat feeders, some of which featuring the sort of in-depth metrics possible when you’ve got on onboard scale. But we can’t help but be impressed with how normal this build looks. If nothing else, of all the feeders we’ve seen, this one is probably the most likely to get cloned and sold commercially. They say it’s the most sincere form of flattery.
As soon as [pashiran] laid eyes on his first hand-cranked music box, he knew he was in love. Then, he started punching the holes for his first ditty. As the repetitive stress of punching heated up his arm, his love cooled a bit. Annealed by the ups and downs of this experience, he decided to design a machine that can punch the holes automatically.
Soon, [pashiran] found his people — a community of music boxers that transform MIDI files to DXF format, which creates coordinates for CAD software. In [pashiran]’s music puncher, an Arduino MEGA takes a DXF file and bubble-sorts the jumble of x-coordinates. The MEGA conducts a trio of two stepper motors and DC motor. One stepper pushes the paper through on the x-axis, and the other moves the puncher head back and forth across the paper scroll as the y-axis. The DC motor moves the punch up and down.
Now, paired with [Martin] of [Wintergatan]’s method for chaining music box paper together, [pashiran] can write a prog-rock-length opus without fear of repetitive stress injury. And since he’s published the STL and INO files, now you can, too. Watch it punch and play 250 notes worth of “See My Vest” “Be Our Guest” after the break.
You probably wouldn’t expect to see somebody making astronomical observations during a cloudy day in the center of a dense urban area, but that’s exactly what was happening at the recent 2019 Philadelphia Mini Maker Faire. Professor James Aguirre of the University of Pennsylvania was there demonstrating the particularly compact Mini Radio Telescope (MRT) project built around an old DirecTV satellite dish and a smattering of low-cost components, giving visitors a view of the sky in a way most had never seen before.
Thanks to the project’s extensive online documentation, anyone with a spare satellite dish and a couple hundred dollars in support hardware can build their very own personal radio telescope that’s capable of observing objects in the sky no matter what the time of day or weather conditions are. Even if you’re not interested in peering into deep space from the comfort of your own home, the MRT offers a framework for building an automatic pan-and-tilt directional antenna platform that could be used for picking up signals from orbiting satellites.
With the slow collapse of satellite television in the United States these dishes are often free for the taking, and a fairly common sight on the sidewalk come garbage day. Perhaps there’s even one (or three) sitting on your own roof as you read this, waiting for a new lease on life in the Netflix Era.
Whether it’s to satisfy your own curiosity or because you want to follow in Professor Aguirre’s footsteps and use it as a tool for STEM outreach, projects like MRT make it easier than ever to build a functional DIY radio telescope.
