Debugging Arduino Is Painful: This Can Help

November 7, 2018 by Al Williams 27 Comments

If you are used to coding with almost any modern tool except the Arduino IDE, you are probably accustomed to having on-chip debugging. Sometimes having that visibility inside the code makes all the difference for squashing bugs. But for the Arduino, most of us resort to just printing print statements in our code to observe behavior. When the code works, we take the print statements out. [JoaoLopesF] wanted something better. So he created an Arduino library and a desktop application that lets you have a little better window into your program’s execution.

To be honest, it isn’t really a debugger in the way you normally think of it. But it does offer several nice features. The most rudimentary is to provide levels of messaging so you can filter out messages you don’t care about. This is sort of like a server’s log severity system. Some messages are warnings and some are informational, and some are verbose. You can select what messages to see.

In addition, the library timestamps the messages so you can tell how much time elapsed between messages and what function you were in during the message. It can also examine and set global variables that you preconfigure and set watches on variables. It is also possible to call functions from the serial monitor.

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Suspense Courtesy Of Arduino, Mess Of Wires

November 6, 2018 by Lewin Day 8 Comments

The ticking clock on the bomb is a Hollywood trope that simply refuses to die. Adding to the stress levels of the bomb squad and creating great suspense for the watcher, it’s always interesting to wonder why the average bomb maker is so courteous as to supply this information to law enforcement. Regardless, if you’d like to build a dramatic prop and are mature enough to do so responsibly, [Giorgio] has the guide you need.

The build is a straightforward one, relying on an Arduino to run the show. This is hooked up to a classic 7-segment LED display, upon which the countdown is displayed. For extra flair, an MP3 player is fitted to play the Mission Impossible theme. It all adds to the tension as you wipe the sweat from your brow, trying to decide if you’re cutting the right wire.

It’s a build that would be an excellent prop for a film production or a fun game at a holiday party. However, it’s also a build that could easily be mistaken for the real thing by those less technically inclined. Even the most innocuous homebrew projects have caused problems for innocent hackers in the past. Fake bombs can be incredibly dangerous, just like the real thing, so it’s important to be careful.

We’ve seen other takes on this kind of build before, too. As always, build responsibly.

Weather Station Is A Tutorial In Low Power Design

November 4, 2018 by Bryan Cockfield 15 Comments

Building your own weather station is a fun project in itself, but building it to be self-sufficient and off-grid adds another set of challenges to the mix. You’ll need a battery and a solar panel to power the station, which means adding at least a regulator and charge controller to your build. If the panel and battery are small, you’ll also need to make some power-saving tweaks to the code as well. (Google Translate from Italian) The tricks that [Danilo Larizza] uses in his build are useful for more than just weather stations though, they’ll be perfect for anyone trying to optimize their off-grid projects for battery and solar panel size.

When it comes to power conservation, the low-hanging fruit is plucked first. [Danilo] set the measurement intervals to as long as possible and put the microcontroller (a NodeMCU) to sleep in between. Removing the power from the sensors when the microcontroller was asleep was another easy step, but the device was still crashing overnight. Then he turned to a hardware solution and added a more efficient battery charger to the setup, which saved even more power. This is all the more impressive because the station communicates via WiFi which is notoriously difficult to run in low-power applications.

Besides the low power optimizations, the weather station itself is interesting for its relative simplicity. It could be built with things most of us have knocking around. Best of all, [Danilo] published the source code on his site, so most of the hard work has been done already. If you’re thinking he seems a little familiar, it’s because we’ve featured some of his projects before, like his cheap WiFi extender antenna and his homemade hybrid tube amplifier.

Gyro Controlled RGB Blinky Ball Will Light Up Your Life

November 2, 2018 by Rich Hawkes 4 Comments

[James Bruton], from the XRobots YouTube channel is known for his multipart robot and cosplay builds. Occasionally, though, he creates a one-off build. Recently, he created a video showing how to build a LED ball that changes color depending on its movement.

The project is built around a series of 3D printed “arms” around a hollow core, each loaded with a strip of APA102 RGB LEDs. An Arduino Mega reads orientation data from an MPU6050 and changes the color of the LEDs based on that input. Two buttons attached to the Mega modify the way that the LEDs change color. The Mega, MPU6050, battery and power circuitry are mounted in the middle of the ball. The DotStar strips are stuck to the outside of the curved arms and the wiring goes from one end of the DotStar strip, up through the middle column of the ball to the top of the next arm. This means more complicated wiring but allows for easier programming of the LEDs.

Unlike [James’] other projects, this one is a quickie, but it works as a great introduction to programming DotStar LEDs with an Arduino, as well as using an accelerometer and gyro chip. The code and the CAD is up on Github if you want to create your own. [James] has had a few of his projects on the site before; check out his Open Dog project, but there’s also another blinky ball project as well.

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This Cup Holder Crystal Ball Tells Your MPG Future

November 1, 2018 by Tom Nardi 22 Comments

Hybrid vehicles, which combine an eco-friendly electric motor with a gasoline engine for extended range, are becoming more and more common. They’re a transitional technology that delivers most of the advantages of pure electric vehicles, but without the “scary” elements of electric vehicle ownership which are still foreign to consumers such as installing a charger in their home. But one element which hybrids are still lacking is a good method for informing the driver whether they’re running on petroleum or lithium; a way to check at a glance how “green” their driving really is.

[Ben Kolin] and his daughter [Alyssa] have come up with a clever hack that allows retrofitting existing hybrid vehicles with an extremely easy to understand indicator of real-time vehicle efficiency. No confusing graphics or arcade-style bleeps and bloops, just a color-changing orb which lives in the cup holder. An evolved version which takes the form of a smaller “dome light” that sits on the top of the dashboard could be a compelling aftermarket accessory for the hybrid market.

The device, which they are calling the ecOrb, relies on an interesting quirk of hybrid vehicles. The OBD II interface, which is used for diagnostics on modern vehicles, apparently only shows the RPM for the gasoline engine in a hybrid. So if the car is in motion but the OBD port is reporting 0 RPM, the vehicle must be running under electric power.

With a Bluetooth OBD adapter plugged into the car, all [Ben] and [Alyssa] needed was an Arduino Nano clone with a HC-05 module to read the current propulsion mode in real-time. With some fairly simple conditional logic they’re able to control the color of an RGB LED based on what the vehicle is doing: green for driving on electric power, purple for gas power, and red for when the gas engine is at idle (the worst case scenario for a hybrid).

Check out our previous coverage of OBD hacking on the Cadillac ELR hybrid if you’re looking to learn more about what’s possible with this rapidly developing class of vehicle

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Hands On With The Arduino FPGA

November 1, 2018 by Al Williams 31 Comments

All of the tools you need to work with the FPGA Arduino — the Vidor — are now in the wild!

We reported earlier that a series of French blog posts finally showed how all the pieces fit together to program the FPGA on the Arduino MKR4000 Vidor board. Of course, I wasn’t content to just read the Google translation, I had to break out the board and try myself.

I created a very simple starter template, a tool in C to do the bitstream conversion, required, and bundled it all together in one place. Here’s how you can use my starter kit to do your own FPGA designs using the Vidor. I’m going to assume you know about FPGA basics and Verilog. If you don’t, why not check out the FPGA boot camps first?

The first thing you’ll want to do is grab my GitHub repo. You’ll also need the Arduino IDE (a recent copy) and Intel’s Quartus software. Inside, you’ll find three directories, two of which contain slightly modified copies of original Arduino files. But before you start digging in, let’s get the high-level overview of the process.

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Spooky Animated Eyes For Your Frightening Needs

October 31, 2018 by Dan Maloney 9 Comments

Unless you have an incredibly well-stocked parts bin, it’s probably too late to build these spooky animated eyes to scare off the neighborhood kiddies this year. But next year…

It’s pretty clear that Halloween decorating has gone over the top recently. It may not be as extreme as some Christmas displays, but plenty of folks like to up the scare-factor, and [wermy] seems to number himself among those with the spirit of the season. Like Christmas lights, these eyes are deployed as a string, but rather than just blink lights, they blink creepy eyes from various kinds of creatures. The eyes are displayed on individual backlit TFT-LCD displays housed in 3D-printed enclosures. Two pairs of eyes can be driven by the SPI interface of one ItsyBitsy M0 Express; driving more displays works, but the frame rate drops to an unacceptable level if you stretch it too far. Strung together on scraps of black ethernet cable, the peepers can live in the shrubs next to the front door or lining the walk, and with surprisingly modest power needs, you’ll get a full night of frights from a USB battery bank.

We like the look of these, and maybe we’ll do something about it next year. If you’re still in the mood to scare and don’t have the time for animated eyes this year, try these simple Arduino blinky eyes for a quick hit.

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