Arduino Hacks

3036 Articles

Know The Load With This Simple Microcontroller CPU Meter

August 5, 2017 by 14 Comments

How do you tell how much load is on a CPU? On a desktop or laptop, the OS usually has some kind of gadget to display the basics. On a microcontroller, though, you’ll have to roll your own CPU load meter with a few parts, some code, and a voltmeter.

We like [Dave Marples]’s simple approach to quantifying something as complex as CPU load. His technique relies on the fact that most embedded controllers are just looping endlessly waiting for something to do. By strategically placing commands that latch an output on while the CPU is busy and then turn it off again when idle, a PWM signal with a duty cycle proportional to the CPU load is created. A voltage divider then scales the maximum output to 1.0 volt, and a capacitor smooths out the signal so the load is represented by a value between 0 and 1 volt. How you display the load is your own choice; [Dave] just used a voltmeter, but anything from an LED strip to some kind of audio feedback would work too.

Still just looking for a load meter for your desktop? Take your pick: an LED matrix, old-time meters, or even Dekatrons.

Mini Hacker Breaks Down How To Build It

August 3, 2017 by 10 Comments

I read the other day that the hot career choice for kids these days is: YouTuber. That means every kid — yes, including mine — has two or three attempts at a YouTube show on their account and then they get into the next big thing and forget about it. On the other hand, sometimes you find someone who has a lot of ideas to share, and the dedication to keep sharing them.

[Kevin Zhou], an 11-year-old from Indonesia, has filmed around  70 videos in the past couple of years, with a fantastic variety of nerdy projects ranging from Mindstorms to Arduino to wood shop projects, and even a Blender tutorial. His projects show a lot of complexity, with serious, real-world concepts, and he shares the technical details about the various components in the project, and he walks you through the code as well.

He made a Mindstorms carving machine, pictured above, with a gantry system holding a motor steady while the user carves into a block of floral foam with LEGO bits. He does a lot of home automation projects using an Arduino and relay board, as well as a number of water-pumping robots. He doesn’t stick to one medium or technology. He has a jigsaw and in one video he shows how to build a Thor’s hammer out of wood. He prints out each layer’s design on office paper and glues the paper to a piece of wood, cutting out the cross-sections on his jigsaw. The whole stack is glued together and clamped. [Kevin]’s design featured a hollow space inside to save weight, which he cut by drilling a 1-inch hole in the center with his drill press, then threading the jigsaw blade through the hole to cut out the inside. As an amateur woodcrafter myself, I like seeing him branching out working on small wood projects.

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Dead Bug Soldered LED Ring Of Awesome

August 2, 2017 by 54 Comments

Sometimes the simplest things in life are the most beautiful. [The Tweaker] has soldered an LED circle on the top of an ATmega328P chip, and it looks great.

Using nothing more than some solder, wire, 20 x Pico 0402 (1mm x 0.5mm) blue LEDs and an ATmega328P (7mm x 7mm), [The Tweaker] managed to cram 20 LEDs into a circle on the top of the chip soldered in dead bug style. The chip is running some Arduino code and is operating on the 8 MHz internal crystal oscillator, so that manages to keep the part count low. The soldering is done in a spiral so the LED terminals are hooked up to the right pins, but it seems to add to the aesthetics of the project and looks like it would take a really steady hand. Once you connect a power source it displays chasing lights as well as other light patterns.

There may not be much to this project but it does look great.

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False Claims On Kickstarter: What’s New?

July 30, 2017 by 56 Comments

Kickstarter and its ilk seem like the Wild West when it comes to claims of being “The world’s most (Insert feature here) device!” It does add something special when you can truly say you have the world record for a device though, and [MellBell Electronics] are currently running a Kickstarter claiming the worlds smallest Arduino compatible board called Pico.

We don’t want to knock them too much, they seem like a legit Kickstarter campaign who have at time of writing doubled their goal, but after watching their promo video, checking out their Kickstarter, and around a couple of minutes research, their claim of being the world’s smallest Arduino-compatible board seems to have been debunked. The Pico measures in at an impressive 0.6 in. x 0.6 in. with a total area of 0.36 sq.in. which is nothing to be sniffed at, but the Nanite 85 which we wrote up back in 2014 measures up at around 0.4 in. x  0.7in. with a total area of around 0.28 sq.in.. In this post-fact, fake news world we live in, does it really matter? Are we splitting hairs? Or are the Pico team a little fast and loose with facts and the truth?

There may be smaller Arduino compatible boards out there, and this is just a case study between these two. We think when it comes to making bold claims like “worlds smallest” or something similar perhaps performing a simple Google search just to be sure may be an idea.

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Arduino Vs. Arduino: Musto Out, Banzi In

July 28, 2017 by 35 Comments

Federico Musto, who until two days ago owned the largest part of Arduino AG has been bought out, having today been replaced by a combination of Massimo Banzi and Fabio Violante.

This should bring to a close the saga that began with a fork where two companies called themselves “Arduino” and bizarrely continued for almost a year after the reconciliation of the two was announced. What remains today is one corporation called Arduino AG, now captained by Massimo Banzi as Chairman and CTO, and Fabio Violante as CEO.

Massimo Banzi was one of the original founders of Arduino and one side of the trademark litigation during the period in which there were two companies. With the buyout of Musto, Banzi moves back to the top spot. This change in leadership occurred as a company called BCMI bought all shares of Arduino AG. BCMI was started by four of the original Arduino co-founders; you could say the old gang rides again.

Arduino AG is in essence a hardware company, manufacturing and selling the officially branded Arduino boards. But right now they still maintain the official codebase which most people see as belonging to the community. Despite changes at the top, the proof will still be in the pudding. When will we see the Arduino Foundation come to life and take control of the Arduino IDE? Hackaday will continue to look into it and provide updates.

 

KIM-1 To COSMAC Elf Conversion — Sort Of

July 25, 2017 by 11 Comments

In the mid-1970s, if you had your own computer, you probably built it. If you had a lot of money and considerable building skill, you could make an Altair 8800 for about $395 — better than the $650 to have it built. However, cheaper alternatives were not far behind.

In 1976, Popular Electronics published plans for a computer called the COSMAC Elf which you could build for under $100, and much less if you had a good junk box. The design was simple enough that you could build it on a piece of perf board or using wire wrap. We featured the online archive of the entire Popular Electronics collection, but hit up page 33 of this PDF if you want to jump right to the article that started it all. The COSMAC Elf is a great little machine built around a 40-pin RCA 1802 processor, and for many was the first computer they owned. I lost my original 1802 computer in a storm and my recent rebuild in another completely different kind of storm. But there is a way to reclaim those glory days without starting from scratch.  I’m going to repurpose another retro-computing recreation; the KIM-1.

I’ll admit it, Rewiring a real KIM-1 to take an 1802 CPU would be difficult and unnecessary and that’s not what this article is about. However, I did have a KIM UNO — [Oscar’s] respin of the classic computer using an Arduino mini pro. Looking at the keyboard, it occurred to me that the Arduino could just as easily simulate an 1802 as it could a 6502. Heck, that’s only two digits different, right?

The result is pretty pleasing. A “real” Elf had 8 toggle switches, but there were several variations that did have keypads, so it isn’t that far off. Most Elf computers had 256 bytes of memory (without an upgrade) but the 1802 UNO (as I’m calling it) has 1K. There’s also a host of other features, including a ROM and a monitor for loading and debugging programs that doesn’t require any space in the emulated 1802.

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Play It Again, Arduino

July 23, 2017 by 11 Comments

[MrRedBeard] wanted to play a particular song from an Arduino program and got tired of trying to hand transcribe the notes. A little research turned up that there was a project to convert Music XML (MXL) files to the Arduino. However, [MrRedBeard] wasn’t a fan of the language it used, so he created his own means of doing the same thing. He learned a lot along the way and was willing to share it in a tutorial that will help you if you want to do the same thing. You can see a video of his results, below.

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