Arduino Hacks

3036 Articles

PJON, Fancy One Wire Arduino Communications Protocol For Home Automation

March 31, 2016 by 44 Comments

PJON, pronounced like the iridescent sky rats found in every city, is a cool one wire protocol designed by [gioblu].

[gioblu] wasn’t impressed with the complications of I2C. He thought one-wire was too proprietary, too complicated, and its Arduino implementations did not impress. What he really wanted was a protocol that could deal with a ton of noise and a weak signal in his home automation project with the smallest amount of wiring possible.

That’s where is his, “Padded Jittering Operative Network,” comes in. It can support up to 255 Arduinos on one bus and its error handling is apparently good enough that you can hold an Arudino in one hand and see the signals transmitted through your body on the other. The fact that a ground and a signal wire is all you need to run a bus supporting 255 devices and they’ll play nice is pretty cool, even if the bandwidth isn’t the most extreme.

Aside from the cool of DIY protocols. We really enjoyed reading the wiki describing it. Some of the proposed uses was running your home automation through your ducting or water pipes (which should be possible if you’re really good at isolating your grounds). Either way, the protocol is neat and looks fun to use. Or check out PJON_ASK if you want to do away with that pesky single wire.

Dirt-Cheap USB Arduino Hack From The Past

March 29, 2016 by 17 Comments

Mass production is a wonderful thing. Prices fall, and hobby hackers get cheap gear. The mind then wanders towards what can be done with it. So it’s little wonder that someone like [Aaron Christophel] would try to repurpose those sub-$3 AVR programmers that are all over eBay (translated poorly out of German here, but demonstrated in the video embedded below).

[Aaron] didn’t have to do much, really. The only trick is that you’ll first need to re-flash the existing ISP firmware with one that lets you upload code to the device itself over USB. If you don’t have an Arduino on hand to re-flash, buy at least two of the cheap programmers — one to program the other ones. Once you’ve done that, you have essentially an Arduino with limited pinout and two onboard LEDs, but in a nice small form-factor and with built-in USB. [Aaron] even provides an Arduino boards.txt file to make it all work smoothly within the IDE.

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What’s Tiny, Has Eight Legs, And Acts Like An Arduino?

March 27, 2016 by 28 Comments

Back in the late 1970s, comedian Steve Martin had a bit about “Let’s get small!” Over on Hackaday.io, [Daniel Grießhaber], has taken that call to heart. He’s been working on DIL-Duino, a minuscule form factor Arduino in an 8-pin DIP format.

Built with an ATtiny85, the board has an area of just under 75 square millimeters (less than 8 mm x 10 mm). If you add the USB port, it still comes in at just over 144 square millimeters. [Daniel] found other small Arduino boards like the Olimexino-85s and the Nanite are not as small as his design.

The module has a QFN CPU and castellated holes around the perimeter for mounting. With pin headers, this would easily fit into a breadboard (as [Daniel] shows) or you could mount it directly to another board like a surface mount device. In fact, that’s the reason for using castellated holes: you can inspect that the solder joint at the mating SMD pad is good. You sometimes hear the technique called half-vias or leadless chip carrier.

If you note, [Daniel] used an oversized board with full holes around the perimeter and then had the board maker score the board, so the holes are cut in half. This is a better technique than trying to drill half holes on the board edge, which is difficult to do.

Naturally, this isn’t the first tiny Arduino we’ve seen. If you are an ARM fan, there’s some little bitty cards for it, too, although not quite as small as DIL-Duino.

Pipe In (Robot) Hand

March 25, 2016 by 5 Comments

How do you make a robot hand? If you are [Robimek], you start with some plastic spiral tubing, some servo motors, and some fishing line. Oh, and you also need an old glove.

The spiral tubing (or pipe, if you prefer) is cut in a hand-like shape and fused together with adhesive. The knuckle joints are cut out to allow the tubing to flex at that point. The fishing line connects the fingertips to the servo motors.

The project uses an Arduino to drive the servos, although you could do the job with any microcontroller. Winding up the fishing line contracts the associated finger. Reeling it out lets the springy plastic pipe pull back to its original position.The glove covers the pipes and adds a realistic look to the hand.
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An Affordable Panasonic Grid-EYE Thermal Imaging Camera

March 24, 2016 by 20 Comments

Thermal imaging cameras are objects of desire for hackers and makers everywhere, but sadly for us they can be rather expensive. When your sensor costs more than a laptop it puts a brake on hacking.

Thankfully help is at hand, in the form of an affordable evaluation board for the Panasonic Grid-EYE thermal imaging camera sensor. This sensor has sparked the interest of the Hackaday community before, featuring in a project that made the 2014 Hackaday Prize semifinals, but has proved extremely difficult to obtain.

All that has now changed though with this board. It features the Grid-EYE sensor itself, an Atmel ATSAM-D21G18A microcontroller, and onboard Bluetooth, but has an interesting feature that, as well as being a standalone device, can be used as an Arduino shield. A full range of APIs are provided, and the code is BSD licensed.

This module is not the highest-spec thermal imaging camera on the market by any means, after all it has a resolution of only 64 pixels in an 8×8 grid. But its affordability and easy availability should trigger a fresh crop of thermal camera projects in our community, and we applaud that.

Thermal camera projects have featured quite a few times here on Hackaday. Some have been based on the FLIR Lepton module, like this one that combines its image with a 640×480 visible camera and another that claims to be one of the smallest thermal cameras, while others have harnessed raw ingenuity to create a thermal camera without a sensor array. This pan-and tilt design for example, or this ingenious use of light painting. Please, keep them coming!

[via oomlout]

Homebrew Multimode Digital Voice Modem

March 23, 2016 by 20 Comments

There’s an old saying that the nice thing about standards is there are so many of them. For digital voice modes, hams have choices of D-Star, DMR, System Fusion, and others. An open source project, the Multimode Digital Voice Modem (MMDVM), allows you to use multiple modes with one set of hardware.

There are some kits available, but [flo_0_] couldn’t wait for his order to arrive. So he built his own version without using a PCB. Since it is a relatively complex circuit for perf board, [flo_0_] used Blackboard to plan the build before heating up a soldering iron. You can see the MMDVM in action below.

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The Infrared Theremin

March 21, 2016 by 4 Comments

The traditional theremin is more or less an audio oscillator with two metal rods. Using proximity sensing, one rod controls the pitch of the oscillator and the other controls the volume. [Teodor Costachiou] apparently asked himself the excellent question: Why does the proximity sensor have to use capacitance? The result is an Arduino-based theremin that uses IR sensors to determine hand position.

[Teodor] used a particular type of Arduino–the Flip and Click–because he wanted to use Click boards for the IR sensors and also to generate sound via an MP3 board based around a VS1053. The trick is that the VS1053 has a realtime MIDI mode, and that’s how this Theremin makes it tones.

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