Tag Archives: uno

1961 rotary phone gets a 2018 cellular upgrade

via Arduino Blog

While it’s hard to beat today’s mobile devices functionality-wise, if you need a phone built like a tank and designed for voice communication and voice communication only, you can’t go wrong with the Western Electric Model 500 rotary telephone. As maker “bicapitate” shows on Imgur, these models include a generous amount of space inside, enough room in fact for an Arduino Uno along with a tiny Adafruit FONA module for cellular capabilities.

While project details are slim, it appears that the Uno takes pulses from the rotary input, then makes calls via the FONA. A DC motor drives the bell to indicate a call is being made, and the original headset, possibly modified with a new speaker and mic, is used for audio. It now also includes a LiPo battery, allowing you to use this wherever convenient—while still slamming the headset down with authority!

PID temperature control with Arduino

via Arduino Blog

If you want to keep something at a certain temperature, say a block of aluminum, you’ll need a thermocouple and some sort of heating element. While you could turn a heater on and off abruptly in a sequence appropriately known as “bang-bang,” a more refined method can be used called PID, or proportional-integral-derivative control. This takes into account how much the temperature is outside of a threshold, and also how it’s changing over time.

As shown in this example by Electronoobs, PID control can be accomplished using an Arduino Uno, along with a type K thermocouple and a MAX6675 module for sensing. The Arduino sketch reads the data and sends the proper amount power to a heating element via a MOSFET in order to maintain the desired temperature without excessive oscillations.

What I want, is the aluminum block below to have let’s say, exactly 100 degrees. I’ll control the real temperature using a K type thermocouple. To read the data I’ll use the MAX6675 breakout module and control the PID algorithm with and Arduino. Finally, to apply power we will make a small circuit using a MOSFET or maybe a TRIAC in case of high AC voltages. This will be a close loop. The thermocouple measures the real values, the Arduino creates the signal applied to the MOSFET and this transistor will control the power of a heating element inside of the aluminum block and once again the thermocouple will measure the value, that’s why it’s a close loop.

Be sure to check it out for an introduction to this powerful control scheme!

MP3 player “reads” CDs like a vintage Victrola

via Arduino Blog

Digital music—which gives us access to a virtually unlimited amount of media at our fingertips—is an amazing innovation. On the other hand, if you get nostalgic for something a bit more tangible, this “Victrola for the 21st century” may just fill that gap.

The device, by maker “castvee8,” plays digital music with the help of an Arduino Uno. Instead of simply emitting the tunes, however, the speaker is augmented with 3D-printed parts to make a horn assembly, and pushed over a CD spinning on a turntable using a worm drive. This creates the illusion that it’s playing digital music in a strange mashup of ‘90s tech and vintage vinyl record players.

My goal was make a music player with a mechanism that simulated a phonograph design but actually was just for aesthetics, and use modern digital media for the actual music. The combination of nostalgia with the modern components like an LCD screen, microcontroller and SD song storage would round this out as a unique build.

The main features of the build are a large cone type speaker supported on a moving axis that scans it across the cd simulating a tonearm pickup, an LCD module that gives instructions such as “press to play” and “select song” with pushbuttons that match, an LED analog level indicator and volume control, a rotating table to turn the cd as if it were being played, and of course the electronics to make it all work. At the end of the song the axis returns home so everything is reset for the next song to be played.

Check it out in the short clip below!

A 3D-printed personal weather station

via Arduino Blog

If you need to know the forecast, generally you can look outside, listen to a weather report, or take advantage of the wide range of online services available. For something local to your dwelling place, however, this 3D-printed weather measurement device gives a great way to see what’s going on.

The system features a 3D-printed rain gauge, anemometer, and weather vane, along with a barometer and temperature sensor. Information from these sensors is piped to an Arduino Uno and displayed on a 4×20 character LCD.

While meant as a demonstration for an arts/science exhibition and would need to be calibrated for real world use, it is a perfect starting point if you’d like to build your own personal station!

The thrust bearings should be a tight fit and not require glue. The 5mm brass tube for the axles though will benefit from some cyanoacrylate on the ABS to hold them in place. Rough the tube up a bit with sandpaper or a file to help adhesion. The temperature and barometric pressure does not need calibrating. However rainfall (it is fairly close) and wind speed will need calibration. As long as the magnet in the wind direction sensor is close enough to trigger two adjacent reed switches when half way between the two reeds, it will allow 8 reed switches to reliably indicate 16 directions.

The reed switches in the direction indicator are vertical and are not trimmed, just the top end curled over to allow easy soldering to the common earth wire ring. Extra spacing maybe required, eg a small ring of heat shrink tubing to keep the moving parts of the anemometer and wind speed separated and seated on the bearings in the stationary base. This was too fine to print.

All the magnets N-S poles should be aligned along the line of the reed switch. The magnet lines of force between N-S have the best switching effect, not one of the poles, N or S, on its own. This also helps eliminate bounce, or multiple triggering.

More details on the project can be found on Thingiverse.

Build a light painting device with Arduino and LEDs

via Arduino Blog

Graffiti with spray paint is generally impolite and illegal, but as hacker “Reven” shows in his write-up, you can get a very similar effect with long exposure photography and carefully-timed LEDs.

Instead of blindly moving a light point about to make this effect, he built his own handheld light painter using an Arduino Uno and a custom enclosure—shared on Thingiverse—to hold everything.

The project’s Arduino sketch can be found here, and adds a 16×2 LCD display to a light painting device conceived of by Phil Burgess for Adafruit, which enables to control the brightness of the LED strip as well as select and load various images from a micro SD card.

This has been done before, many, many times; and even commercially. But I wanted to build my own, both to learn in the process and because commercial options were out of my budget. I chose adafruit’s implementation as a starting point, because it worked on the hardware I already had and they have provided detailed instructions. I also wanted some additional features: I wanted to add a display and a menu system to be able to choose the image to display and adjust the settings (like brightness or speed). I also wanted to be able to turn off the brightness balancing that adafruit’s sketch did, because frame or animation painting wasn’t something I really needed. And most importantly, I adjusted the project to the materials I had at hand.

With this fantastic build in hand, Reven can now produce beautiful light graffiti wherever it’s needed!

Designing a fake dynamic price tag

via Arduino Blog

Wile we know on some level that prices adjust to market conditions, with Amazon now owning Whole Foods, one could perhaps see a day when this happens electronically and instantaneously.

To get a preview of what this might look like, maker “msbirfday” decided to create a random price generator based on an Arduino Uno and a 16×2 LED display. This was then disguised as an official price tag, and set up in a store to observe how shoppers reacted.

The unit blends in nicely, and while employees might get annoyed at the device, it’s certainly an ingenious prank.

Amazon’s recent acquisition of Whole Foods Market made us wonder: what’s stopping dynamic pricing from stepping into the physical world of retail? What if the prices in a supermarket were just as flexible as those online?

Check out how it was made here, and see it in action in the video below!