To capture images of bullets “interacting” with various objects, photographic hacker Tyler Gerritsen created an impressive chronograph rig, able to measure the speed of a bullet launched from a rifle at 1000 meters per second. While the concept of measuring time from one sensor to another isn’t new, implementation at this speed required some interesting tricks.
To accomplish this feat, Gerritsen designed his own sensor array using photodiodes in a reverse-biased setup, and even calibrated the clock speed of the Arduino Uno for control in order to account for any variation. Finally, the time between triggering a flash and light actually appearing had to be compensated for in the code, a different value for each type of equipment.
Water is essential to life on earth, and making sure our rivers and lakes are free from pollution is therefore quite important. For environmental monitoring, students from Bergen County Academics Magnet High School have come up with the Intelli-Buoy system that can track water turbidity, pH, oxygen, and temperature levels for analysis. It can also keep tabs on wind speed and rain stats for possible correlation.
The floating device uses a pair of Arduino Unos with an SD card shield mounted on each in order to record these statistics over several days, and it’s designed with two external USB ports for easy access.
Be sure to check out this orange PVC sensor assembly the video seen here.
What’s the best way to dispose of the dust that is produced when cutting with power tools? YouTuber Bob Claggett’s answer is to automate the process entirely, using a series of PVC sewer pipes to transport air to a central vacuum system, along with an Arduino Uno for control.
Airflow is regulated via a blast gate for each power tool, which is opened and shut using a hobby-style servo and custom linkage system. The powerful dust collector is controlled with the help of a relay.
Cleverly, a voltage sensor is employed for each power tool needing dust collection, allowing the Arduino to turn on the system and decide which gate to open without any human interaction.
When you see a mechanical clock, you know on some level that it took a vast amount of expertise and craftsmanship to get working, but you might also assume that this could all be swapped out very easily with modern electronics. While this might be the case with a clock that only tells time, as David Henshaw shows with his project, once you add in extra features like a moon phase, date indicator, and chimes, things get complicated quickly.
Henshaw began by purchasing an 1847 vintage clock from England without the movement—the parts that actually it tell time. He then replaced the mechanical assembly normally found inside with stepper motors, sensors, an Arduino Uno, and a variety of other wires and bits.
You can see the retrofitted grandfather clock in action below, while the build process (which took the better part of a year) and Arduino code he used are outlined on his website.
Alejandro Clavijo, together with his father Jerónimo, spent two years building the first official fan-made model of the R4-P17 Star Wars droid. For those not familiar with this family of droids, R4-P17 was the robot companion to the young Obi-Wan Kenobi.
The replica is made of aluminum and wood, and runs on four Arduino boards. Impressively, the project has also been approved by Lucasfilm, the studio behind the saga, allowing Clavijo to bring it to official Star Wars events all over the world.
When not recreating Star Wars characters, Clavijo spends his days working as an engineer and has designed controls for “clean rooms” using Arduino Uno. You can see his design–made with CATIA–on Thingiverse.
As outlined in this Circuit Digest write-up, with the right hardware, you can now control your computer using hand gestures. While interesting, this kind of technology can be a little expensive. But if you’d like to augment your notebook or laptop via simple gesture capabilities without breaking the bank, B. Aswinth Raj has your answer in the form of an Arduino Uno and two ultrasonic sensors.
His system places the two sensors at the top of a screen, which are read by the Uno. This data is then passed on to a Python program running on the host computer that allows for actions such as play/pause, fast-forward, and volume control while watching videos.
Given the nature of the setup, there’s no reason why more sensors or programming couldn’t be added for further control, perhaps as shortcut “keys” for your favorite design software package! You can read more about the project here, and see a demo of it below.