Arduino Versus Logic: The Coil Gun War Continues

Looks like another shot has been fired in the simmering Coil Gun Control War. This time, [Great Scott] is taken to the discrete woodshed with a simplified and improved control circuit using a single CMOS chip and a few transistors. Where will it end? Won’t somebody think of the children?

The latest salvo is in response to [GreatScott]’s attempt to control a DIY coil gun with discrete logic, which in turn was a response to comments that he took the easy way out and used an Arduino in the original build. [Great Scott]’s second build was intended to justify the original design choice, and seemed to do a good job of explaining how much easier and better the build was with a microcontroller. Case closed, right?

Nope. Embedded designer [fede.tft] wasn’t sure the design was even close to optimized, so he got to work — on his vacation, no less!’ He trimmed the component count down to a single CMOS chip (a quad Schmitt trigger NAND), a couple of switching transistors, the MOSFETs that drive the coils, and a few passives. The NANDs are set up as flip-flops that are triggered and reset by the projectile sensors, which are implemented as hardwired AND gates. The total component count is actually less than the support components on the original Arduino build, and [fede.tft] goes so far as to offer ideas for an alternative that does away with the switching transistors.

Even though [fede.tft] admits that [GreatScott] has him beat since he actually built both his circuits, hats off to him for showing us what can likely be accomplished with just a few components. We’d like to see someone implement this design, and see just how simple it can get.

Filed under: Arduino Hacks, weapons hacks

DIY Voltmeter With Arduino and a Nokia 5110 Display

In this Instructable I am going to show you how to build a a Voltmeter with a big Nokia 5110 LCD display using Arduino. Building a Voltmeter is a great learning experience. When you finish building this project you will have a better understanding of how Voltmeters work, you will refresh your knowle...
By: educ8s

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Instructables 25 Aug 09:29

Robotized Trashcan

Hi. This project is about robo trashcan, that will open its cap if you pass your hand above it. The trashcan will open its cap for 10 seconds ifyou place your hand from 10 to 30 centimeters above the cap, and for 3 seconds if your hand will be at the distance from 30 to 70 centimeters. This mode is ...
By: AlexGyver

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Instructables 25 Aug 08:28

Rainy Day Fun by Calculating Pi

If you need a truly random event generator, just wait till your next rainstorm. Whether any given spot on the ground is hit by a drop at a particular time is anyone’s guess, and such randomness is key to this simple rig that estimates the value of pi using raindrop sensors.

You may recall [AlphaPhoenix]’s recent electroshock Settlers of Catan expeditor. The idea with this less shocking build is to estimate the value of pi using the ratio of the area of a square sensor to a circular one. Simple piezo transducers serve as impact sensors that feed an Arduino and count the relative number of raindrops hitting the sensors. In the first video below, we see that as more data accumulates, the Arduino’s estimate of pi eventually converges on the well-known 3.14159 value. The second video has details of the math behind the method, plus a discussion of the real-world problems that cropped up during testing — turns out that waterproofing and grounding were both key to noise-free data from the sensor pads.

In the end, [AlphaPhoenix] isn’t proving anything new, but we like the method here and can see applications for it. What about using such sensors to detect individual popcorn kernels popping to demonstrate the Gaussian distribution? We also can’t help but think of other ways to measure raindrops; how about strain gauges that weigh the rainwater as it accumulates differentially in square and circular containers? Share your ideas in the comments below.

[via r/electronics]

Filed under: Arduino Hacks, misc hacks
Hack a Day 25 Aug 03:01

Arduino: Stepper Motor Example Sketch Fixed

Like most of the example sketches you get with the Arduino IDE the Stepper Motor example which rotates the stepper motor 1 full turn clockwise and then 1 full turn counter-clockwise does not work. It was last updated 7 years ago and a lot has changed since then.In this Instructable I show you the pr...
By: CommunityWorkshops

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Instructables 25 Aug 00:41

Car Tracking Device

There is always a need to protect your belongings specially your car, put your things are safe in some place, on the other hand your car is left in the streets. Consequently, this project will help you to track your car and know its location by only calling a specific number ( actually your car numb...
By: Moniem_17

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Instructables 24 Aug 22:11

Raspberry Echo Pi

Describe your collection here... null null null null null An Echo Device using the C.H.I.P. $9 Computer AlexaPi + IFTTT Voice Control through Echo (Demo Video) Home Automation with Amazon Echo voice control Control any remote from a Raspberry Pi (and Amazon Ech...
By: Scoshi

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Instructables 24 Aug 21:34

Teenage student creates a wearable system to reduce concussions

For a high school science fair project, Berto Garcia came up with an idea to help reduce concussions among football players. Now a student at Texas Tech University, he holds a provisional patent for the award-winning, life-changing project.

The helmet-and-shoulder pads system consists of an Arduino connected to four sensors around the front and inside of the helmet, which is programmed to stabilize immediately after impact. When the stabilizers are not activated, players have full movement. But when a wearer suffers a hit above a certain threshold, the board activates the stabilizers, locking the helmet into place and stiffening up to reduce the whiplash motion of the neck. It doesn’t stop the impact of the initial hit, but it keeps the head from rattling around inside the helmet after the collision.

The sensors are also able to measure the amount of force with which athletes are hit and, using a radio, can wirelessly transmit that data to trainers on the sideline. Knowing that could help healthcare professionals diagnose concussions more accurately. Given recent events around concussions and traumatic brain injuries, Garcia’s idea can certainly play an imperative role in the future of sports.

Read all about the Texas Tech undergrad’s project here.


Twoway Switching

This instructable is for beginners & it is collection of different logic circuit diagrams.In this instructables I will show you how to use Two way switches for controlling output manually &from microcontroller.This is requirement of many projects.This is concept is use for switching stair case Bulbs...
By: Saurabh Gangamwar47

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Instructables 24 Aug 20:16

Auto Turtle/fish Feeder

I'm always too lazy to feed my turtle or i forgot it, so i decide to make this simple feeder. What you need: Some arduinoServoWiresEmpty box from feedKnivePiece of plexiglassLighter Preparing parts You need to make hole with knive and lighter. It must be sufficiently large so granules may fal...
By: DanielR34

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Instructables 24 Aug 18:04