Posts | Comments

Planet Arduino

You are stuck at home quarantined and you want to do some Arduino projects. The problem is you don’t have all the cool devices you want to use. Sure, you can order them, but the stores are slow shipping things that aren’t essential these days. If you want to get a headstart while you are waiting for the postman, check out Wokwi’s Playground. For example, you can write code to drive a virtual NeoPixel 16×16 matrix. There’s even example code to get you started.

There are quite a few other choices in the playground including Charlieplexed LEDs, a keypad, and an LCD. There are also challenges. For example, in the traffic light challenge, you are given code that uses a task scheduler library to implement a traffic light. You have to add a turn signal to the code.

In addition to LEDs in various configurations, the site has some serial bus components, an LCD, a keypad, and a NeoPixel strip. There are also a few tools including an EasyEDA to KiCad converter and a way to share sourcecode similar to Pastebin.

Of course, simulations only get you so far, but the site is a fun way to play with some different I/O devices. It would be very nice if you could compose for the different components together, but you could work your code in sections, if necessary. You can do similar things with TinkerCad circuits. If you want to install software, there’s a simulator for you, too.

Kaleb Clark really enjoys flight simulators, but when attempting to fly a helicopter, a normal keyboard or even a joystick isn’t quite optimal for controlling its vertical movement. Real helicopters use a lever assembly called a collective to adjust downward thrust, and he decided to build his own with an Arduino Micro and GPIO expander.

To read the main lever action, he’s using a gear and encoder setup, which allows him to lift and descent in a much more natural way than afforded normal computer controls. There’s also has a bunch of buttons attached that can be programmed for various actions as needed. 

Game interface is taken care of by the Micro’s ATmega32U4 chip, giving it HID functionality as an auxiliary input device.

Timepieces are cool no matter how simplistic or granular they are. Sometimes its nice not to know exactly what time it is down to the second, and most of the really beautiful clocks are simple as can be. If you didn’t know this was a clock, it would still be fascinating to watch the bearings race around the face.

This clock takes design cues from the Story clock, a visual revolution in counting down time which uses magnetic levitation to move a single bearing around the face exactly once over a duration of any length as set by the user. As a clock, it’s not very useful, so there’s a digital readout that still doesn’t justify the $800 price tag.

[tomatoskins] designed a DIY version that’s far more elegant. It has two ball bearings that move around the surface against hidden magnets — an hour ball and a minute ball. Inside there’s a pair of 3D-printed ring gears that are each driven by a stepper motor and controlled with an Arduino Nano and a real-time clock module. The body is made of plywood reclaimed from a bed frame, and [tomatoskins] added a walnut veneer for timeless class.

In addition to the code, STLs, and CAD files that birthed the STLs, [tomatoskins] has a juicy 3D-printing tip to offer. The gears had to be printed in interlocked pieces, but these seams can be sealed with a solution of acetone and plastic from supports and failed prints.

If you dig minimalism but think this clock is a bit too vague to read, here’s a huge digital clock made from small analog clocks.

After picking up a free arcade machine, YouTuber “Another Maker” has naturally been considering what to do with it. One of the more interesting components included is the 1/5/10/20 U.S. dollar bill acceptor, which he outlines in the video below.

The cash reader is powered by a 12V supply, and “emulates” quarter inputs to the machine by sending multiple signals for each bill. Meaning, a dollar would be output as four quarters, five times that for a five dollar bill, and so on. This functionality is shown at the end of the clip on an Arduino Mega with an LCD keypad shield. The machine also has a 5V input, which can activated by an Arduino to make it flash LEDs and reject all bills when “business is closed.”

The code that enables it to read the device can be found on GitHub. And in case you’re wondering what Another Maker ended up building…

Combating COVID-19 Conference: A Collaborative Arduino Community Initiative will take place today, April 2nd starting at 5pm CEST.

The online event will be streamed via Zoom. From 5:00 to 5:30pm, there will be only one streaming channel (LINK HERE). After that, we’ll break out into two different rooms (LINK TO ZOOM ROOM 1, LINK TO ZOOM ROOM 2).

There are different ways to participate: presenting an Arduino-based solution to tackle COVID-19 (the call for projects is now closed), supporting other community projects, providing expert advice, or asking the Arduino team for some support.

This conference schedule is as follows:

5:00 – 5:30pm CEST – Plenary Introductory Session – LINK TO ZOOM ROOM 1

  • David Cuartielles, “The Arduino Community Response to the COVID-19 Outbreak.”
  • Robert Read (https://www.pubinv.org/), “Open Source Hardware for the Emergency”

5:30 – 7:00pm CEST – Session 1: Arduino-Based Ventilators and Medical Devices

7:00 – 8:30pm CEST – Session 2: Legal and Technological Challenges

There are different channels to join the discussion with the Arduino team and community:


Giovanni Carrera has created a capable power monitor, dubbed the ArduINA226, using an Arduino Nano and an INA226 IC. 

This chip measures the current and voltage, and calculates power, which is then read by the Arduino board and sent to an LCD display. The unit also features a micro SD card for storage and later analysis, letting you track stats such as energy consumption over time.

Nearly any sort of Arduino board can be used for this setup, but the Nano was chosen as it makes things nice and compact and has an included USB adapter. The electronics are mounted on a PCB and housed in a professional-looking enclosure. 

A full schematic for the ArduINA226 is available in Carrera’s project write-up, along with code if you’d like to make your own.

We’ve all seen, and occasionally wrestled with, bill acceptors like the one [Another Maker] recently liberated from an arcade machine. But have you ever had one apart to see how it works? If not, the video after the break is an interesting peak into how this ubiquitous piece of hardware tells the difference between a real bill and a piece of paper.

But [Another Maker] goes a bit farther than just showing the internals of the device. He also went through the trouble of figuring out how to talk to it with an Arduino, which makes all sorts of money-grabbing projects possible. Even if collecting paper money isn’t your kind of thing, it’s still interesting to see how this gadget works on a hardware and software level.

As explained in the video, a set of belts are used to pull the bill past an array of IR LEDs. The hardware uses these to scan the bill and perform some dark magic to determine if it’s a genuine piece of currency. [Another Maker] notes that these readers actually need to receive occasional firmware updates to take into account new bill designs. In fact, the particular unit he has is so out of date that it won’t accept modern $5 bills; which may explain how he got it for free in the first place.

Years ago we saw one of these bill acceptors used to make a DIY Bitcoin ATM. Of course back then, a few bucks would get you a semi-reasonable amount of BTC. These days you would skip the paper currency and do it all digitally.

 

Awkward silences can be highly uncomfortable. Thankfully, they’re a problem that can be solved by technology. Chatty Coaster aims to do just this, detecting pauses in conversation and interjecting with helpful questions to move things along.

The coaster is built around an Arduino Micro, which uses a microphone to detect audio levels in the room. When it detects an extended silence, it then fires off a sound clip using a Sparkfun audio breakout board. The questions vary from plain to politically sensitive, so there’s a good chance you could get some spicy conversation as a result. Any talking device runs a risk of being more annoying than helpful, and there’s certainly a risk that Chatty Coaster could fall into this category. Choosing the right content seems key here.

Overall, while this may not be the ultimate solution to boring company, it could get a laugh or two and serves as a good way to learn how to work with audio on microcontrollers. Video after the break.

We’ll admit, when we were reading this one, we thought we had deja vu. But this one’s a lot less blamey.

With the current coronavirus situation, we’ve been encouraged to wash our hands regularly for 20 seconds – or approximately how long it takes you to hum “Happy Birthday” from beginning to end twice. That sounds easy enough, but do you really do this every time? What you need is some sort of automatic timer, perhaps with a dial gauge for easy visual reference. 

As it just so happens, Gautam Bose and Lucas Ochoa built such a device with an Arduino Uno. The aptly named Wash-A-Lot-Bot detects a person’s hands in front of it via an ultrasonic sensor, then ticks a dial timer from 0 to 20 (or rather 20 to DONE!) using a micro servo. 

This simple setup can be made with little more than scissors and tape, making it a great way to learn about Arduino and programming while you’re stuck indoors.

No matter who you are,  you produce garbage of some kind or another. Two students decided they wanted to create a smart garbage can that could alert them when the can is full or even when it is stinky.

We will go on on the record: we didn’t know that an alcohol sensor could tell if your garbage is stinky, so if that works, that’s a new one on us. However, it makes a certain kind of sense because garbage ferments. We thought garbage smelled because of hydrogen sulfide and methane.

Trash cans have a tough life, so if you really want to duplicate this, you’ll probably want to mount things a bit more securely. The software, however, runs everything through a cloud service and from there can use Blynk for a phone app and IFTTT to ship things to a spreadsheet, should you care to track your garbage history statistics.

You can see in the video this is a small proof of concept can. We almost want to build one just to see if the sensor really knows when the can is smelly.

Granted, the project may not be the most practical, but it is amazing how easy it is now to build devices with a high degree of connectivity thanks to the wealth of inexpensive boards and services available.

This isn’t the first time we’ve seen Blynk. For that matter, it isn’t even our first smart trash can.



  • Newsletter

    Sign up for the PlanetArduino Newsletter, which delivers the most popular articles via e-mail to your inbox every week. Just fill in the information below and submit.

  • Like Us on Facebook