Raspberry Pi

1836 Articles

Lock Up Your Raspberry Pi With Google Authenticator

September 30, 2016 by 14 Comments

Raspberry Pi boards (or any of the many similar boards) are handy to leave at odd places to talk to the network and collect data, control things, or do whatever other tasks you need a tiny fanless computer to do. Of course, any time you have a computer on a network, you are inviting hackers (and not our kind of hackers) to break in.

We recently looked at how to tunnel ssh using a reverse proxy via Pagekite so you can connect to a Pi even through firewalls and at dynamic IP addresses. How do you stop a bad guy from trying to log in repeatedly until they have access? This can work on any Linux machine, but for this tutorial I’ll use Raspberry Pi as the example device. In all cases, knowing how to set up adequate ssh security is paramount for anything you drop onto a network.

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Raspberry Pi Adds A Digital Dash To Your Car

September 28, 2016 by 37 Comments

Looking for a way to make your older car more hi-tech? Why not add a fancy digital display? This hack from [Greg Matthews] does just that, using a Raspberry Pi, a OBD-II Consult reader and an LCD screen to create a digital dash that can run alongside (or in front of ) your old-school analog dials.

[Greg’s] hack uses a Raspberry Pi Foundation display, which includes a touch screen, so you don’t need a mouse or other controls. Node.js displays the speed, RPM, and engine temperature (check engine lights and other warnings are planned additions) through a webpage displayed using Chromium. The Node page is pulling info from another program on the Pi which monitors the CAN Consult bus. It would be interesting to adapt this to use with more futuristic displays, maybe something like a pico projector and a 1-way mirror for a heads-up display.

To power the system [Greg] is using a Mausberry power supply which draws power from your car battery, but which also cleanly shuts down the Pi when the ignition is turned off so it won’t drain your battery. When you throw in an eBay sourced OBD-II Consult reader and the Consult Dash software that [Greg] wrote to interpret and display the data from the OBD-II Consult bus, you get a decent digital dash display. Sure, it isn’t a Tesla touchscreen, but at $170, it’s a lot cheaper. Spend more and you can easily move that 60″ from your livingroom out to your hoopty and still use a Raspberry Pi.

What kind of extras would you build into this system? Gamification of your speed? Long-term fuel averaging? Let us know in the comments.

UPDATE – This post originally listed this hack as working from the OBD-II bus. However, this car does not have OBD-II, but instead uses Consult, an older data bus used by Nissan. Apologies for any confusion!

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Hackaday Prize Entry: Raspberry Pi Thermal Imaging

September 25, 2016 by 12 Comments

High up on the list of desirable technologies that are edging into the realm of the affordable for the experimenter is the thermal camera. Once the exclusive preserve of those with huge budgets, over the last few years we’ve seen the emergence of cameras that are more affordable, and most recently a selection of thermal camera modules that are definitely within the experimenter’s range. They may not yet have high resolution, but they are a huge improvement on nothing, and they are starting to appear in projects featured on sites like this one.

One such device is the Melexis MLX90621, a 16×4 pixel thermal sensor array in a TO39 can with an I2C interface. It’s hardly an impulse purchase in single quantities and nor is it necessarily the cheapest module available, but its price is low enough for [Alpha Charlie] to experiment with interfacing it to a Raspberry Pi for adding a thermal camera overlay to the pictures from its visible light camera.

The wiring for the module is simplicity itself, and he’s created a couple of pieces of software for it that are available on his GitHub repository. mlxd is a driver daemon for the module, and mixview.py is a Python graphical overlay script that places the thermal array output over the camera output. A run-through of the device and its results can be seen in the video below the break.

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Want To Wake Up In A Ship’s Warp Core? Circadia Sunrise Clock Makes It So

September 22, 2016 by 24 Comments

Who among you has difficulty rising in the mornings? Sunrise clocks that simulate a — well, sunrise,  are a gentle means of returning to the waking world. [FlorianH], grappling with this very issue, has built his own impressive sunrise clock he has named Circadia. Some sunrise clocks mate an LED with a dev board and call it a day. This work of hardware art will never be confused for something rudimentary.

Standing at 187cm tall, the 8mm thick PCB frame contains three main sections that plug into each other “like Lego”: the top houses a cleverly designed (and virtually silent) propeller clock and a speaker with a 3D-printed, omni-directional reflector. The midsection is reinforced with an MDF column, around which is wrapped 16 strips of 18 RGB LEDs with a heat-molded sheet of acrylic to diffuse the light, while the bottom section has the mid-woofer, the Raspberry Pi 2 brain, most of the electronics, and three switched power supplies.

Built over two years, the primary feature is a variety of themes — with more being added all the time — ranging from rain forest, to arctic, to the warp core of a starship that will rouse you over the course of a half hour. Circadia can also function as a visualizer during a party, or even a Tetris display (a theme that was designed and tested in an afternoon!). Seeing it in action is a treat:

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How To Run A Pagekite Server To Expose Your Raspberry Pi

September 21, 2016 by 9 Comments

Last time I showed you how to expose a web service on a Raspberry Pi (or, actually, any kind of device) by using a reverse proxy from Pagekite. On your Pi, you just need a simple Python script. However, it also depends on the Pagekite server, which isn’t always convenient. There are limits to the free service, and you don’t control the entire thing. The good news is twofold: the same Python script you use to set up the client-side can also set up a server. The other good news is the entire thing is open source.

In practical terms, then, if you have a computer that is always on and has an IP address that can be found on the public internet, you can run your own Pagekite server (they call it a front end) and service your own backends.

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Expose Your Raspberry Pi On Any Network

September 20, 2016 by 42 Comments

Everyone’s talking about the Internet of Things (IoT) these days. If you are a long-time Hackaday reader, I’d imagine you are like me and thinking: “so what?” We’ve been building network-connected embedded systems for years. Back in 2003, I wrote a book called Embedded Internet Design — save your money, it is way out of date now and the hardware it describes is all obsolete. But my point is, the Internet of Things isn’t a child of this decade. Only the name is.

The big news — if you can call it that — is that the network is virtually everywhere. That means you can connect things you never would have before. It also means you get a lot of data you have to find a reason to use. Back in 2003, it wasn’t always easy to get a board on the Internet. The TINI boards I used (later named MxTNI) had an Ethernet port. But your toaster or washing machine probably didn’t have a cable next to it in those days.

Today boards like the Raspberry Pi, the Beagle Bone, and their many imitators make it easy to get a small functioning computer on the network — wired or wireless. And wireless is everywhere. If it isn’t, you can do 3G or 4G. If you are out in the sticks, you can consider satellite. All of these options are cheaper than ever before.

The Problem

There’s still one problem. Sure, the network is everywhere. But that network is decidedly slanted at letting you get to the outside world. Want to read CNN or watch Netflix? Sure. But turning your computer into a server is a little different. Most low-cost network options are asymmetrical. They download faster than they upload. You can’t do much about that except throw more money at your network provider. But also, most inexpensive options expose one IP address to the world and then do Network Address Translation (NAT) to distribute service to local devices like PCs, phones, and tablets. What’s worse is, you share that public address with others, so your IP address is subject to change on a whim.

What do you do if you want to put a Raspberry Pi, for example, on a network and expose it? If you control the whole network, it isn’t that hard. You usually use some kind of dynamic DNS service that lets the Pi (or any computer) tell a well-known server its current IP address (see figure below).

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The Cicada: A Parasite Art Piece With Commitment Issues

September 19, 2016 by 18 Comments

How often do you think deeply about the products around you? How about those you owned five years ago? Ten? The Cicada — brainchild of [Daniel Kerris] — is an art piece that aims to have the observer reflect on consumer culture, buyer’s remorse, and wanting what we cannot have.

The Cicada consists of an ultrasonic sensor feeding data to a Raspberry pi which — calculating the distance of an approaching human — either speeds up or slows down a servo motor connected to a General Electric Walkman’s cassette speed potentiometer. Upon detecting someone approaching, The Cicada begins to loop the chorus of Celine Dion’s “I Will Always Love You”. As you move closer, the tape speed slows, and there is a transition from love at first sight to nightmarish drawl as the music slows.

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