The proliferation of breakout boards that the DIY electronics movement has allowed has been staggering. Buy a few different boards, wire them together to a microcontroller or credit-card computer (both on their own breakout board) and write a bit of code, and you can create some really interesting things. Take Reddit user [Lord_of_Bone]’s Nerf Gun ammo counter and range finder, for example, a great example of having a great idea and looking around for the ways to implement it.
For the range finder, [Lord_of_Bone] looked to an ultrasonic rangefinder. For the ammo counter, [Lord_of_Bone] chose a proximity sensor. To run everything, the Raspberry Pi Zero was used and the visuals were supplied by a Rainbow Hat. The range finder is self-explanatory. The proximity sensor is located at the end of the gun’s muzzle and when it detects a Nerf dart passing by it reduces the ammo count by one. Blu-tack is used to hold everything in place, but [Lord_of_Bone] plans to use Sugru when he’s past the prototype stage.
The one problem [Lord_of_Bone] has with the build is that there’s no way to tell how many Nerf bullets are in the magazine. Currently the wielder must push a button when reloading to reset the count to a preset amount. We’re sure that [Lord_of_Bone] would appreciate any suggestions the Hack-A-Day crowd could offer.
[Lord_of_Bone] gives a full bill of materials, Python code, a lot of pictures and step-by-step instructions so that you, too, can determine how far away your target is, and whether or not you have enough ammo to hit them. We have quite a few Nerf mods on the site, and [Lord_of_Bone] could take a look at this article about how to keep track of your Nerf ammo, and here’s a different method of determining if a Nerf dart has been fired (and measuring its speed.)
[via Reddit] Continue reading “Nerf Gun Ammo Counter and Range Finder”
The wood router is a versatile power tool which can be picked up at a low price. Nicer router setups are mounted underneath a table, with the cutting head poking through. This makes it easier and safer to work with the tool.
[Paul] combined his interest in electronics and woodworking by making a router table with automated controls [translation]. The neat part of this build is the automated height control, which ensures accurate cutting depth.
The router is mounted to a threaded rod, which allows it to be moved up and down by a motor. A low cost L298 motor driver provides the power to the motor, which is controlled by an Arduino Uno. A VCNL4020 based sensor board is used to measure distance and accurately set the router height. This tiny proximity sensor looks like a nifty chip, providing distance measurements up to 200 mm and an ambient light sensor in one package.
The routing table has an LCD display and buttons, allowing the user to dial in their desired height. The entire thing was built using recycled bits and well under $100 in new parts.
A team of students from Cornell University are looking into alternative ways of creating a security system that can be locked or unlocked by using physical gestures in an enclosed space.
It is the final year project for [Ankur], [Darshan] and [Saisrinivasan] in their MEng of Electrical and Computer Engineering. The system prototype is capable of recording a gesture and then comparing the gesture with future gestures to lock or unlock the system. Consider it like a secret handshake to get into the office!
To analyze the gesture they are using four SparkFun proximity sensors setup in a linear array to sense the distance a hand is moved. An ATMega1284P is used to convert the analog sensor signal to digital for further processing. The project is extremely well documented, as it appears to be the final report for the project.
A short video after the break shows off the prototype and gives a good explanation of how the system works.
Continue reading “Gesture Based Security Lock”
This pair of musical keyboard hacks both use light to detect inputs. The pair of tips came in on the same day, which sparks talk of consipiracy theory here at Hackaday. Something in the weather must influence what types of projects people take on because we frequently see trends like this one. Video of both projects is embedded after the jump.
On the left is a light-sensitive keyboard which [Kaziem] is showing off. In this image he’s rolling a marble around on the surface. As it passes over the Cadmium Sulfide sensors (which are arranged in the pattern of white and black keys from a piano keyboard) the instrument plays pitches based on the changing light levels. [Thanks Michael via Make]
To the right is [Lex’s] proximity sensor keyboard. It uses a half-dozen Infrared proximity sensor which pick up reflected light. He calls it a ‘quantised theremin’ and after seeing it in action we understand why. The overclocked Raspberry Pi playing the tones reacts differently based on distance from the keyboard itself, and hand alignment with the different sensors.
Continue reading “Pair of musical hacks use sensor arrays as keyboards”
[Dustin Andrews] built this add-on board which works as a proximity sensor. He wanted a standalone sensor for his Arduino projects which would use a single pin as a trigger. This lets him alert the Arduino when an object approaches the sensor without the need for polling or extra code on the Arduino side of things.
As you can see, a single chip on the board takes care of all the work. That’s an ATtiny13, they’re inexpensive and sometimes you can even salvage them from consumer electronics like this color changing light bulb. The microcontroller monitors the phototransistor which is wrapped in electrical tape to isolate it from the IR LED emitters on either side. This setup creates a reflective sensor. When an object nears the board, the infrared light from the emitters reflects off of it and onto the phototransistor. And since the Arduino works as an AVR programmer you don’t need special hardware to program the device.
[Achu Wilson] was watching TV when he saw an ad for Volkswagen’s latest Passat, which happens to come equipped with a park assist mode. This essentially allows the car to park itself with little to no user interaction. While these systems come as a pricey add-on option, he figured he could build something similar in his own home, albeit on a much smaller scale.
Digging through his parts bin he only came across a single infrared proximity sensor, so instead of building vehicle that could parallel park, he settled on constructing one that can situate itself in a traditional parking spot instead. The car is built from wood and a pair of DC motors [Achu] had on hand, both of which are controlled using an ATmega16.
As a proof of concept, it looks to work pretty well despite the fact that it only has a single fixed sensor navigate its surroundings. We imagine it would be a relatively easy task to adapt the system for parallel parking, among other things.
Continue reading to see [Achu’s] self-parking car in action.
Continue reading “Build your own miniature self parking car”
Finally [Michelle Annett] can talk about her super secret project she did at Autodesk Research.
Medusa, as [Michelle]’s project is called, is a Microsoft Surface that has been fitted with 138 proximity sensors. This allows the Surface to sense users walking up to it, and detect users hands and arms above the table top. Multiple users can be detected at the same time, and the left and right hands of two users can be mapped to specific users.
The proximity sensors [Michelle] used are inexpensive, so we’re wondering when someone with a crazy multitouch setup will add proximity sensors to their build. We’d like to play with Medusa, even if just for a virtual game of Settlers of Catan. It seems like the perfect setup…
[Michelle] built Medusa last January during her internship at Autodesk. Now that UIST 2011 is over, she can finally talk about it. There’s also a video demonstrating the possibilities of Medusa, check it out after the break.
Thanks [Fraser] for sending this one in.
Continue reading “Medusa: a proximity-aware tabletop”