Multiple OLEDs? Save Pins By Sharing the I2C Clock

Inexpensive OLED displays with I2C interfaces abound, but there is a catch: they tend to be stuck on I2C address 0x3C. Some have a jumper or solder pads to select an alternate (usually 0x3D), but they lack any other method. Since an I2C bus expects every device to have a …read more

Continue reading Multiple OLEDs? Save Pins By Sharing the I2C Clock→

Get Twelve Charlieplexed PWM Outputs From an ATtiny85

Most of us are aware that charlieplexing can drive a large number of LEDs from a relatively small number of I/O pins, but [David Johnson-Davies] demonstrates adding another dimension to that method to create individually controlled PWM outputs as well. His ATtiny85 has twelve LEDs, each with individually-set brightness levels, …read more

Continue reading Get Twelve Charlieplexed PWM Outputs From an ATtiny85→

Downloadable 3D Cockpits Enhance FPV Racing

First Person View (or First Person Video) in RC refers to piloting a remote-controlled vehicle or aircraft via a video link, and while serious racers will mount the camera in whatever way offers the best advantage, it’s always fun to mount the camera where a miniature pilot’s head would be, and therefore obtain a more immersive view of the action. [SupermotoXL] is clearly a fan of this approach, and shared downloadable designs for 3D printed cockpit kits for a few models of RC cars, including a more generic assembly for use with other vehicles. The models provide a dash, steering …read more

Continue reading Downloadable 3D Cockpits Enhance FPV Racing→

Calling World Cup Goals Before They Happen, By Polling a Betting Site

[Ben] made an interesting discovery during the FIFA World Cup in 2018, and used it to grant himself the power to call goals before they happened. Well, before they happened on live TV or live streaming, anyway. It was possible because of the broadcast delay on “live” broadcasts, combined with the sports betting industry’s need for timely and detailed game state tracking.

He discovered that a company named Running Ball provides fairly detailed game statistics in digital form, which are generated from inside the stadium as events occur. An obvious consumer of this data are sports betting services, and [Ben] …read more

Continue reading Calling World Cup Goals Before They Happen, By Polling a Betting Site→

Palm-Sized Gatling Gun Has 32 Mini Elastics With Your Name On Them

One thing 3D printers excel at is being able to easily create objects that would be daunting by other methods, something that also allows for rapid design iteration. That’s apparent in [Canino]’s palm-sized, gatling-style, motorized 32-elastic launcher.

The cannon has a rotary barrel driven by a small motor, and a clever sear design uses the rotation of the barrels like a worm gear. The rotating barrel has a spiral formation of hooks which anchor the stretched elastic bands. A small ramp rides that spiral gap, lifting ends of stretched bands one at a time as the assembly turns. This movement …read more

Continue reading Palm-Sized Gatling Gun Has 32 Mini Elastics With Your Name On Them→

Three-Conductor Pivot for E-Textiles is Better Than Wires

Pivots for e-textiles can seem like a trivial problem. After all, wires and fabrics bend and flex just fine. However, things that are worn on a body can have trickier needs. Snap connectors are the usual way to get both an electrical connection and a pivot point, but they provide only a single conductor. When [KOBAKANT] had a need for a pivoting connection with three electrical conductors, they came up with a design that did exactly that by using a flexible circuit board integrated to a single button snap.

This interesting design is part of a solution to a specific …read more

Continue reading Three-Conductor Pivot for E-Textiles is Better Than Wires→

How To Make Bisected Pine Cones Look Great, Step-by-Step

[Black Beard Projects] sealed some pine cones in colored resin, then cut them in half and polished them up. The results look great, but what’s really good about this project is that it clearly demonstrates the necessary steps and techniques from beginning to end. He even employs some homemade equipment, to boot.

Briefly, the process is to first bake the pine cones to remove any moisture. Then they get coated in a heat-activated resin for stabilizing, which is a process that infuses and pre-seals the pine cones for better casting results. The prepped pine cones go into molds, clear resin …read more

Continue reading How To Make Bisected Pine Cones Look Great, Step-by-Step→

Kinematic Mount For 3D Printer Bed Shows Practical Design

[Mark Rehorst] has been busy designing and building 3D printers, and Son of Megamax — one of his earlier builds — needed a bed heater replacement. He took the opportunity to add a Kelvin-type kinematic mount as well. The kinematic mount and base efficiently constrain the bed in a controlled way while allowing for thermal expansion, providing a stable platform that also allows for removal and repeatable re-positioning.

After a short discussion regarding the heater replacement, [Mark] explains the design and manufacture of his kinematic mount. Of particular note are the practical considerations of the design; [Mark] aimed to use …read more

Continue reading Kinematic Mount For 3D Printer Bed Shows Practical Design→

How To Time Drone Races Without Transponders

Drone racing is nifty as heck, and a need all races share is a way to track lap times. One way to do it is to use transponders attached to each racer, and use a receiver unit of some kind to clock them as they pass by. People have rolled their own transponder designs with some success, but the next step is ditching add-on transponders entirely, and that’s exactly what the Delta 5 Race Timer project does.

The open-sourced design has a clever approach. In drone racing, each aircraft is remotely piloted over a wireless video link. Since every drone …read more

Continue reading How To Time Drone Races Without Transponders→

Supportless Overhangs: Just Reorient Gravity by 90 Degrees

The 3D print by [critsrandom] in the image above may not look like much at first glance, until one realizes that the 90 degree overhang has no supports whatsoever. Never mind the messy bottom surface, and never mind that the part shown might avoid the problem entirely with some simple supports or a different print orientation; the fact that it printed at all is incredible.

[critsrandom] shared the method in a post on Reddit, and it consists simply of laying the 3D printer on its side. When the print head reaches the overhang, the fact that it is printing sideways …read more

Continue reading Supportless Overhangs: Just Reorient Gravity by 90 Degrees→