Stator Library Makes Your Arduino Code Easier To Read

May 9, 2019 by Lewin Day 56 Comments

The readability of your code can make the difference between your project being a joy to work on, or an absolute headache. This goes double when collaborating with others. Having easily parsed code reduces your cognitive load and makes solving problems easier. To try and help with this, [PTS93] developed the Stator library to make certain common tasks simpler to read.

The aim of the library is to get rid of piles of state tracking variables and endless if/else statements – hence the name. It’s designed primarily for the Arduino IDE but doesn’t have any dependencies on the API, so can be used in other C++ environments. It comes with a variety of neat tools for common jobs, such as reading an analog sensor with hysteresis around a trigger point, as well as easy ways to track state changes across multiple variables. By using basic English terms instead of condition checks and mathematical operators, it can make things more readable and easier to follow.

The power of the Arduino platform has always been in its easy to use libraries that make everything easier, from interfacing LCDs to working with Amazon Dash buttons.

Arduino’s Pluggable Discovery Programs With Any Protocol

May 8, 2019 by Brian Benchoff 9 Comments

The first Arduino was serial, and over the decade and a half, this has been the default way to upload code to an Arduino board. In 2008, support for in-circuit programmers was added, and later port detection was added. The latest version of the Arduino IDE adds something new: pluggable discovery. Now any protocol is supported by the Arduino IDE.

This feature is the brainchild of [Paul Stoffregen], creator of the Teensy. If you’ve ever used a Teensy, you’ll remember the Teensyduino application used to upload code to the board. The Teensy uses HID protocol instead of serial for uploading. After working to improve the integration between the Teensy and Arduino IDE, [Paul] stated extending the DiscoveryManager. After some discussion with the Arduino developers, this feature was then added to Arduino 1.8.9, released a month or so ago.

There are some issues with Pluggable Discovery, most importantly that it doesn’t yet exist in the Arduino Command Line Interface (yeah, that exists too). If you’re looking to contribute to Open Source, that would be a nice project to pick up.

With the right JSON, and configuration, it is now theoretically possible to extend the Arduino IDE to any sort of protocol. This means (again, theoretically), it’s possible to update the firmware in your DIY MIDI synth over SysEx message, or a parallel port, maybe. Someone is going to upload to an Arduino board over PCIe, eventually.

Arduino Leonardo Gets A Lockable Bootloader

May 7, 2019 by Lewin Day 19 Comments

Security is something that’s far too often overlooked in embedded devices. One of the main risks is that if the device doesn’t verify the authenticity of incoming firmware updates. [Walter Schreppers] was working on a USB password storage device, so security was paramount. Thus, it was necessary to develop a secure bootloader.

[Walter]’s device was based upon the Arduino Leonardo. Starting with the Caterina bootloader, modifications were made to enable the device to be locked and unlocked for programming. This can be done in a variety of ways, depending on how things are setup. Unlocking can be by using a secret serial string, an onboard jumper, and [Walter] even suspects a SHA1 challenge/response could be used if you were so inclined.

It’s never too soon to start thinking about security in your projects. After all, we must stave off the cyberpunk future in which leather-clad youths flick all your lights on and off before burning your house down in the night by overclocking the water heater. Naturally, we’ve got a primer to get you going in the right direction. Happy hacking!

Insert Coin (Cell) To Play LedCade

May 6, 2019 by Roger Cheng 3 Comments

In this era of 4K UHD game console graphics and controllers packed full of buttons, triggers, and joysticks, it’s good to occasionally take a step back from the leading edge. Take a breath and remind ourselves that we don’t always need all those pixels and buttons to have some fun. The LedCade is a μ (micro) arcade game cabinet built by [bobricius] for just this kind of minimalist gaming.

Using just three buttons for input and an 8×8 LED matrix for output, the LedCade can nevertheless play ten different games representing classic genres of retro arcade gaming. And in a brilliant implementation of classic hardware hacking humor, a player starts their game by inserting not a monetary coin but a CR2032 coin cell battery.

Behind the screen is a piezo speaker for appropriately vintage game sounds, and an ATmega328 with Arduino code orchestrating the fun. [bobricius] is well practiced at integrating all of these components as a result of developing an earlier project, the single board game console. This time around, the printed circuit board goes beyond being the backbone, the PCB sheet is broken apart and reformed as the enclosure. With classic arcade cabinet proportions, at a far smaller scale.

If single player minimalist gaming isn’t your thing, check out this head-to-head gaming action on 8×8 LED arrays. Or if you prefer your minimalist gaming hardware to be paper-thin, put all the parts on a flexible circuit as the Arduflexboy does.

Play Tetris On A Transistor Tester, Because Why Not?

May 3, 2019 by Bryan Cockfield 4 Comments

[Robson] had been using the same multimeter since he was 15. It wasn’t a typical multimeter, either. He had programmed it to also play the Google Chrome jumping dinosaur game, and also used it as a badge at various conferences. But with all that abuse, the ribbon cable broke and he set about on other projects. Like this transistor tester that was just asking to have Tetris programmed onto its tiny screen.

The transistor tester is a GM328A made for various transistor testing applications, but is also an LCR meter. [Robson]’s old meter didn’t even test for capacitance but he was able to get many years of use out of that one, so this device should serve him even better. Once it was delivered he set about adding more features, namely Tetris. It’s based on an ATmega chip, which quite easy to work with (it’s the same chip as you’ll find in the Arduino Uno but [Robson’s] gone the Makefile route instead of spinning up that IDE). Not only did he add more features, but he also found a mistake in the frequency counter circuitry that he fixed on his own through the course of the project.

If you’ve always thought that the lack of games on your multimeter was a total deal breaker, this project is worth a read. Even if you just have a random device lying around that happens to be based on an ATmega chip of some sort, this is a good primer of getting that device to do other things as well. This situation is a fairly common one to be in, too.

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Simple, Self-Contained LoRa Repeater In About An Hour

May 2, 2019 by Donald Papp 5 Comments

[Dave Akerman]’s interest in high-altitude projects means he is no stranger to long-range wireless communications, for which LoRa is amazingly useful. LoRa is a method of transmitting at relatively low data rates with low power over long distances.

Despite LoRa’s long range, sometimes the transmissions of a device (like a balloon’s landed payload) cannot be received directly because it is too far away, or hidden behind buildings and geography. In these cases a useful solution is [Dave]’s self-contained LoRa repeater. The repeater hardware is simple, and [Dave] says that if one has the parts on hand, it can be built in about an hour.

The device simply re-transmits any telemetry packets it receives, and all that takes is an Arduino Mini Pro and a small LoRa module. A tiny DC-DC converter, battery, and battery charger rounds out the bill of materials to create a small and self-contained unit that can be raised up on a mast, flown on a kite, or carried by a drone.

The repeater’s frequency and other settings can even be reprogrammed (using a small windows program) for maximum flexibility, making the little device invaluable when going hunting for landed payloads like the one [Dave] used to re-create a famous NASA image using a plastic model and a high-altitude balloon. Check out the details on the GitHub repository for the project and start mashing “add to cart” for parts at your favorite reseller.

A Physical Knob For Browser Tabs

April 30, 2019 by Brian Benchoff 35 Comments

If you’re like most of us, you have about twenty browser tabs open right now. What if there were a way to move through those tabs with a physical interface? That’s what [Zoe] did, and it’s happening with the best laptop ever made.

The hardware for this build is simply an Arduino and a rotary encoder, no problem there. The firmware on the Arduino simply reads the encoder and sends a bit or two of data over the serial port. This build gets interesting when you connect it to a Firefox extension that allows you to get data from a USB or serial port, and there’s a nice API to access tabs. Put all of this together, and you have a knob that will scroll through all your open tabs.

This build gets really good when you consider there’s also a 3D printed mount, meant to attach to a Thinkpad X220, the greatest laptop ever made. At the flick of a knob, you can scroll through all your tabs. It’s handy if you’re reading three or four or five documents simultaneously, or if you’re just editing video and trying to go through your notes at the same time. A great invention, and we’re waiting for this to become a standard device on keyboards and mice. Check out the video below.

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