Posts with «arduino» label

Core Memory: Why We Used 60-Year-Old Tech in an Arduino Shield

About ten years ago, we designed and made an Arduino shield implementing “core memory,” a technology that was sixty years old even then. Our shield stored 32 individual 1s or 0s using magnetic fields going either clockwise or anticlockwise around 32 tiny doughnuts of magnetisable ‘ferrite’ material. This kind of memory, invented in the 1950s, […]

The post Core Memory: Why We Used 60-Year-Old Tech in an Arduino Shield appeared first on Make: DIY Projects and Ideas for Makers.

Quit Hunching Over Your Screen With A Little Robotic Help

[Norbert Zare] has identified a problem many of us suffer from – chronically bad posture. Its very common to see computer users hunched forwards over a screen, which eventually will lead to back problems. He mentions that most posture correction devices are pretty boring, so the obvious solution to [Norbert] was to build a simple robot to give you a friendly nudge into the correct position.

This simple Arduino-based build uses the ubiquitous MPU-6050 which provides 3-axis acceleration and 3-axis gyro data all processed on-chip, so it can measure where you’re going, which way you are orientated and how fast you are rotating. This is communicated via the I2C bus, so hooking into an Arduino or Raspberry Pi is a simple affair. There are plenty of Open Source libraries to work with this very common device, which helps reduce the learning curve for those unfamiliar with programming a fairly complex device.

At the moment, he is mounting the sensor on his body, and hard-wiring it, so there’s already some scope for improvement there. The operating premise is simple, if the body angle is more than 55 degrees off vertical, move the servos and shove the body back in to the correct position.

The project GitHub has the code needed, and the project page over on Hackaday.io shows the wiring diagram.

We have seen quite a few projects on this subject over the years, like this one that sends you mobile notifications, an ultrasonic rangefinder-based device, and one that even uses a webcam to keep an eye on you. This one has the silliness-factor, and we like that round these parts. Keep an eye on [Norbert] we’re sure there more good stuff to come!

Hack a Day 21 Oct 00:00

Flickering Jack o’ Lantern Is An Easy Beginner Build

The Jack o’ Lantern is a fun Halloween tradition, though one that does come with a few risks. It’s pretty easy to slice off a bit of finger when carving a stiff pumpkin, and candles draw more enmity from fire crews than most household items. For the electronics beginner looking for a learning project, [Oyvind’s] build might be a nice safe bet.

The build starts with a 3D-printed pumpkin figurine with a suitably spooky face, though [Oyvind] notes there’s nothing stopping this project from being executed with a real orange gourd instead. Inside, an Arduino is hooked up to a trio of orange LEDs. They’re attached to PWM pins and each is given a random brightness value at regular intervals to create a pleasant flickering effect.

It’s a very simple project, but it’s also the kind of thing that’s perfect for introducing new people into the world of electronics. There’s little to get wrong, and mistakes aren’t costly, making it an ideal project for beginners. From there, the sky really is the limit! Video after the break.

The Quadrivium EnsembleBot Is A Labour Of Love

The Quadrivium EnsembleBot project is a mashup between old school musical instruments and the modern MIDI controlled world. Built by a small team over several years, these hand crafted instruments look and sound really nice.

The electronics side of things is taken care of with a pile of Arduinos and off-the-shelf modules, but that doesn’t mean the design isn’t well thought through, if a little more complicated than it could be in places. Control is taken care of with a PC sending commands over the USB to an Arduino 2560. This first Arduino is referred to as the Master Controller and has the immediate job of driving the percussive instruments as well as other instruments that are struck with simple solenoids. All these inductive loads are switched via opto-isolators to keep any noise generated by switching away from the microcontroller. A chain of four sixteen-channel GPIO expander modules are hung off the I2C bus to give even more opto-isolated outputs, as even the Arduino 2560 doesn’t quite have enough GPIO pins available. The are a number of instruments that have more complex control requirements, and these are connected to dedicated slave Arduinos via an SPI-to-CAN module. These are in various states of development, which we’ll be keeping our beady eyes on.

One of the more complex instruments is the PipeDream61 which is their second attempt to build a robotic pipe organ. This is powered by a Teensy, as they considered the Arduino to be a little too tight on resources. This organ has a temperature controller using an ATTiny85, in order to further relieve the main controller of such a burden and simplify the development a little.

Another interesting instrument is Robro, which is a robotic resophonic guitar which as they say is still work in progress despite how long they have been trying to get it to work. There’s clearly a fair bit of control complexity here, which is why it is taking so much fiddling (heh!) to get it work.

This project is by no means unique, lately we’ve covered controlling a church organ with MIDI, as well as a neat Arduino Orchestra, but the EnsembleBot is just so much more.

Thanks [gjerman] for the tip!

Hack a Day 19 Oct 16:30

Laser Pointer and Arduino Make a Minimalistic Shooting Game

Video games are great and all, but sometimes you just want the thrill of manipulating actual objects in addition to watching action on a screen. This must have been the reason why Nintendo’s Duck Hunt became so popular despite the simplicity of its gameplay. Prolific hacker [mircemk] similarly made a computer-plus-physical game called “Laser Shooter“, which somehow reminds us of the good old NES game.

The game is based on an Arduino Nano, to which five LEDs as well as five photoresistors (LDRs) are connected. When the game is started, the LEDs light up at random and the player has a limited time to “shoot” the corresponding LDR with a laser pointer. This time limit is decreased as the game progresses, and the game is over once the player fails to hit the target on time. The “Game Over” message is accompanied by a sad tune, but luckily no giggling dog.

Complete schematics and code are available for anyone willing to try their hand at replicating or improving this game. And no, you can’t simply sweep your laser across the five LDRs all the time, because you lose if you shoot at the wrong target. For more laser pointer-based games, try this Laser Command clone or this laser tag badge system.

It’s A Hack: Air Scrubber Controlled Using The Room Lighting

Some products just seem to be designed to be annoying. [hardmar] discovered the air filtration system installed in his son’s basement woodshop was orientated for the best airflow, but rather poorly positioned to actually turning the thing on and off. For some reason the unit has its single line-of-sight IR receiver on one side, which when mounted in some positions, forces the user to be the completely wrong position to use the supplied remote.

We find it a little unhelpful sometimes that devices specifically designed to be mounted with varying orientations don’t come fitted with IR receivers in different locations to ensure good controllability. It would get annoying really fast to have to contort oneself into some specific position just to turn something on, and some people just might not bother at all.

Proper control of dust is paramount for continued good health, and essential in any workspace or shared area. When you work wood, it produces a lot of dust. It cannot be avoided and gets into everything, your lungs included. PPE is not enough.  Even in your own shop you still really should manage dust production as best you can. Options are varied from centralised extraction, per machine solutions, and often augmented with air scrubbers mounted on the ceiling to grab those fine particulates.

Instead of solving the IR placement issue, [hardmar] wanted to have the unit tied to the lighting system so that it would power on as soon as someone turned on the appropriate light and would then stay on for a fixed amount of time after the user left in order to continue scrubbing the air some more. His simple hack was to first record and analyse the IR protocol used by the remote, and program an Arduino to be able to send it on/off commands. Next, he hooked up a phototransistor aimed at the light, in order to provide the necessary ‘user present’ trigger to tell the Arduino when to activate the scrubber. Super simple and effective. We love this non-invasive approach of adapting off-the-shelf equipment to our specific requirements, without even showing it a screwdriver.

As [hardmar] admits, the hack is not elegantly implemented, it’s just enough to make it work, and that’s just fine, sometimes you just have a job to do and no more.

Tiny TV Tells the Temperature Tale

Once upon a time, we would run home from the bus stop to watch Gargoyles and Brady Bunch reruns on the family TV, a late-1970s console Magnavox number that sat on the floor and was about 50% more cabinet than CRT. The old TV, a streamlined white Zenith at least ten years older, had been relegated to the man cave in the basement. It looked so mod compared to the “new” TV, but that’s not the aesthetic my folks were after. They wanted their electronics to double as furniture.

This little TV is a happy medium between the two styles, and for us, it’s all about those feet. But instead of cartoons, it switches between showing the current weather and the top news headlines. Inside that classy oak cabinet is an LCD, an ESP32, and an SD card module. The TV uses OpenWeatherMap and pulls the corresponding weather image from the SD card based on time of day — light images for day, and dark images for night.

We love that it shows the SMPTE color bars, aka the standard American TV test pattern as it switches between weather and news. After showing the top headlines, it automatically switches back to the weather channel. Be sure to check out the short demo video after the break.

Do you like your tiny televisions in strange places? Here’s one you can use to trim your tree this year.

Using Arduinos To Drive Undocumented Displays

For those of us old enough to remember the VCR (and the difficulty of programming one), the ubiquitous vacuum fluorescent display, or VFD, is burned into our memories, mostly because of their brightness and contrast when compared to the superficially-similar LCD. These displays are incredibly common even apart from VCRs, though, and it’s easy to find them for next to no cost, but figuring out how to drive one if you just pulled it out of a 30-year-old VCR is going to take some effort. In this build, [mircemk] shows us how he drives unknown VFD displays using an Arduino in order to build his own weather forecasting station.

For this demonstration [mircemk] decided to turn a VFD into a weather forecasting station. First of all, though, he had to get the VFD up and running. For this unit, which came from a point-of-sale (POS) terminal, simply connecting power to the device turned on a demo mode for the display which let him know some information about it. From there, and with the knowledge that most POS terminals use RS232 to communicate, he was able to zero in on the Rx and Tx pins on the on-board microcontroller and interface them with an Arduino. From there it’s a short step to being able to output whatever he wanted to this display.

For this project, [mircemk] wanted the display to output information about weather, but rather than simply pull data from some weather API he is actually using a sensor suite connected to the Arduino to measure things like barometric pressure in order to make a 12-hour forecast. The design is inspired by old Zambretti weather forecasters which used analog wheels to input local weather data. It’s an interesting build not only for the VFD implementation but also for attempting to forecast the weather directly with just a tiny sensor set instead of downloading a forecast to display. To do any better with your own forecasts, you’d likely need your own weather station.

Giant Working NERF Gun Runs on Tiny Arduino

Well, here it is: a shoe-in for the new world’s largest NERF gun. (Video, embedded below.) The Guinness people haven’t shown up yet to award [Michael Pick], but at 12.5 feet, this baby is over twice as long as the current record holder, which belongs to former NASA mechanical engineer Mark Rober and his now-puny six-foot six-shooter.

We have to wonder if it is technically bigger than the six-shooter, because they seem to be roughly the same scale, except that [Michael] chose a much bigger model to start from. The main body is made from wood, and there are a ton of 3D-printed details that make it look fantastically accurate. The whole thing weighs over 200 pounds and takes at least two people to move it around. We especially love the DIY darts that [Michael] came up with, which are made from a PVC tube inside a section of pool noodle, topped off with a 3D printed piece for that distinctive orange cap.

Propelling those darts at around 50 MPH is a 3,000 PSI air tank connected to an Arduino Pro Mini that controls the trigger and the air valves. While [Michael] hasn’t run the thing quite that high, it does plenty of damage in the neighborhood of 40-80 PSI. As you’ll see in the video after the break, this is quite the ranged weapon. Watch it blow a hole clean through a sheet of drywall and much more.

Want to build something with a bit more stealth? Make it death from above with a NERF quadcopter.

TICO Robot Plays Tic-Tac-Toe by Drawing on a Tiny Whiteboard

Tic-tac-toe (or “Noughts and Crosses”) is a game simple enough to implement in any computer system: indeed it’s often used in beginner’s programming courses. A more challenging project, and arguably more interesting and useful, is to make some kind of hardware that can play it in real life. [mircemk] built a simple yet elegant machine that can play tic-tac-toe against a human player in a way that looks quite similar to the way humans play against one another: by drawing.

The robot’s design and programming were developed at PlayRobotics, who named the project TICO. The mechanical parts are available as STL files, to be printed by any 3D printer, and a comprehensive manual explains how to assemble and program the whole thing. Since it’s all open source, anyone can build it from scratch and modify it to their liking. The pictures show the original design by PlayRobotics, while the video (embedded after the break) shows [mircemk]’s version, which includes a wooden frame that gives it a bit more presence.


The electronic components are an Arduino with an OLED screen and a buzzer, plus three servos to operate the mechanical parts. Lacking a 3D printer, [mircemk] cut the plastic parts from a 3 mm sheet of PVC, which seems to have worked surprisingly well. The game board consists of a small whiteboard on which the robot and the human can draw their O’s and X’s.

The mechanical structure of the robot looks a bit like a tiny human using both arms to draw with an enormous marker. When starting a game, the robot clears the whiteboard using a little eraser, then draws the standard 3×3 grid and makes its first move. The human then draws their move and uses a remote control to tell the robot what they did (no machine vision here), after which the game continues until there is either a winner or the game results in a draw.

Although it looks like the program’s playing strategy may need some fine-tuning, the mechanical part is well-designed and the arms’ motions are quick and steady. We love the celebratory “cheering” at the end of a game, which TICO does whether it won or not.

The robot’s basic design is inspired by the Plotclock, which uses a similar setup to draw the time. We’ve seen other tic-tac-toe ‘bots before, as well as some clever electronic implementations of the game.

Hack a Day 28 Sep 00:00