Pi Zero HackChat With Lady Ada

December 2, 2015 by Mike Szczys 104 Comments

This Thursday, December 3rd, join us for a Live HackChat about the Raspberry Pi Zero with special guest [Limor Fried]. You may know [Limor] as [Lady Ada], the founder of Adafruit Industries. Adafruit has been on the forefront of the Pi Zero release. The $5 single board computer was announced one week ago by the Raspberry Pi Foundation.

Join in the chat to discuss the Raspberry Pi Zero. Limor has done a lot of work with the board already, including hacking analog audio back into the form factor. This is a great opportunity to ask questions, talk about your own plans for the hardware, and to find collaborators for future projects.

Pi Zero HackChat starts Thursday at 5pm PST (here’s a timezone cheat sheet if you need it). Participating in this live chat is very simple. Those who are already part of the Hacker Channel can simply click on the Team Messaging button. If you’re not part of the channel, just go to the hacker Channel page, scroll to the bottom of the “TEAM” list in the left sidebar and click “Request to join this project”.

HackChat takes place in the Hacker Channel every few weeks and is a friendly place to talk about engineering and the projects you’re working on.

Raspberry Pi Zero, Or Minus One?

December 1, 2015 by Rud Merriam 274 Comments

The Wall Street Journal reported that [Eric Schmidt] of Google and now Alphabet Inc, promoted the idea of an inexpensive version of the Raspberry Pi to the Raspberry Pi foundation’s [Eben Upton]. Apparently [Upton] accepted this recommendation despite existing plans to make a more expensive, more powerful version of the Pi. The outcome is the Raspberry Pi Zero that sells, in some places, for $5.00 and was given away for free on the cover of the MagPi magazine.

From the WSJ article:

“He [Schmidt] said it was very hard to compete with cheap. He made a very compelling case. It was a life-changing conversation,” Mr. Upton said, adding that he went back to the lab and scrapped all the engineering plans for more expensive versions of future Pi computers. “The idea was to make a more powerful thing at the same price, and then make a cheaper thing with the same power.”

Plans were scrapped. The more powerful Pi 2 was released at the price point of existing Pis, and now we have the Zero.

Pi’s Purpose

The Raspberry Pi Foundation is a registered educational charity in the UK. The purpose of this Foundation according to their About Us page is to, ‘advance the education of adults and children, particularly in the field of computers, computer science, and related subjects.’

Why is the Raspberry Pi Foundation so concerned about computer education? From the 1990s onward, fewer and fewer A Level students in the UK applying to study Computer Science had previous experience as hobbyist programmers. An applicant in the 2000s usually might have only done a little web design.

Why then does the Raspberry Pi Zero exist? [Upton] also told Cnet, “We really hope this is going to get those last few people in the door and involved in computer programming.”

Very good, but how well does the Zero support this goal or address their concerns?

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Listening To The Sounds Of The Earth

December 1, 2015 by Rud Merriam 19 Comments

A geophone is a specially built microphone for listening to the Earth. [JTAdams] found them at a reasonable price so bought some to play with. A geophone is used to detect vibrations from earthquakes, explosions, rumbling trucks, and vibroseis vehicles. To be useful it needs an amplifier and a recording device to capture the signals.

[JTAdams] used a standard amplifier design for an LT1677 op-amp, fed the signal to an MCP3008 A/D converter, and read the output using a Raspberry Pi. A Python script records the data to a CSV file for processing. The Pi worked well because the entire setup needs to be portable to take into the field. Another Python script plots the data which is made available from a web page. A neat simple way of presenting the raw data. [JTAdams] promises more information in the future on post-processing the data. You don’t need a geophone to detect seismic waves if you build your own, but a real ‘phone will be more rugged.

Oh, what’s a vibroseis? It’s a truck with a big flat plate underneath it. The plate is hydraulically lowered to the ground until the weight of the truck is on it. The truck then causes the plate to vibrate, usually sweeping from around 10 hz to 100 hz. This infrasound pass through the ground until it is reflected back by underlying rock layers. A long string of geophones, think 1,000s of feet, detects the waves, which are recorded. In practice, many trucks are used to generate a synchronized signal of sufficient strength. Or, you can set off an explosion which is the technique used in water. Typically the information is used for oil and gas exploration. A video of one of the trucks in action after the break.

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RasPi LED Panel Library Is Nyan-tastic

November 29, 2015 by Sonya Vasquez 5 Comments

Quick–in a pinch, let’s have ourselves a giant RGB LED Matrix! As marvelous as it sounds, it’s pretty easy to forget that there’s a battle to be won against picking the right parts, debugging drivers, and sorting out our spaghetti wiring. Rest assured, [Hzeller] has done all of the heavy-lifting for us with a Raspberry Pi RGB LED Matrix Implementation that scales to multiple panels and runs on any Pi model to date!

Offering 24-bit color at about 100 Hz for up to a grand total of 36 panels, [Hzeller’s] library is no slouch. The library enables customization of your panel arrangements, and a separate project (also [Hzeller’s] handiwork) makes this setup compatible with the pixel-pusher protocol as a network device.

It’s certainly true that many of us have a thing for these displays, so you might ask: “have we seen this before? What’s all the fuss?” Like the others, the final product is a sight to behold, but [hzeller] and his implementation stands strong because of his phenomenal response to answering the question: how? In fact, almost more impressive is his comprehensive online documentation. Inside, [hzeller] details various hardware configurations for a custom number of panels or a particular flavor of Pi that drives them. He also provides references for pinout quirks and provides out-of-the-box software demos to ensure that anyone can bring this project to life. If a poorly-written or non-existent READMEs have made you shy away from building on an open-source project, fear not. From pinout quirks and out-of-the-box software demos, [hzeller] has covered all the bases and given us a project that folks of all levels of hacking.

Perhaps the best part of this project is the span of the audience that can take something away from it. If you’re a seasoned Linux junkie, dive into the source code to get a good feel of mechanics of how [hzeller] pushes this project onto a single core in a Raspi-2 configuration. If you’re new to digital electronics, let this project be your moment to pick up a Pi, a panel (or four), and run, knowing that [hzeller’s] README is the only tome you’ll need to light up the night.

We had the honor of soaking up some Nyan-Cat rainbows with a live demo at this year’s SuperCon.

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Office Dog Triangulation Keeps Spot Accounted For

November 29, 2015 by James Hobson 40 Comments

[Matt Reed] works at a pet friendly work-space, where his pooch called [Bean] loves to wander around and disappear. She’s not getting in trouble, but nonetheless, [Matt] worries about her. So he took the creepy stalker route and put a beacon on her collar to track her every move.

He’s using a small BLE beacon that will poll a signal every second, sending out a unique ID code and a RSSI value (Received Signal Strength Indicator). Normally beacons are placed in a stationary location to help people navigate — but this time, it’s on a moving dog.

In order to better understand [Bean’s] location in the office, [Matt] set up three Raspberry Pi’s with Bluetooth adapters around the office. Using Noble, Node.js listens for the RSSI values and triangulates [Bean’s] position, much like a cellphone can be located using different ping times from cellular towers.

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First Raspberry Pi Zero Hack – Piggy-Back WiFi.

November 28, 2015 by Rud Merriam 122 Comments

And we have the first Raspberry Pi Zero hack! In less than 72 hours from the official release announcement [Shintaro] attached an Edimax WiFi USB Adapter directly to the USB solder pads on the Pi Zero. He couldn’t bear to disturb the small dimensions of the Pi Zero by using the USB On-the-Go (OTG). The OTG is needed to convert the micro-USB connector on the board to a full USB-A connector.

The case was removed from the Edimax and the device and Zero wrapped in Kapton to insulate the exposed solder points. Power was taken from the PP1 and PP6 points on the back of the board. These are the unregulated inputs from the USB power so should be used with caution. Some cheap USB power supplies can put out more that 5 volts when first connected and that might let the smoke out of a device.

The data wires were connected to PP22 and PP23, also on the back, and behind the USB data connector. Since USB is a differential signal these wires were carefully kept of equal length to avoid distorting the signal.

An SD card was created and edited on a Raspberry Pi B 2 to set the WiFi credentials. Inserted into the Zero it booted fine and started up the WiFi network connection.

Congratulations, [Shintaro] for the first Hackaday Raspberry Pi Zero hack. Is that a Hack-a-Zero-Day hack?

The $5 Raspberry Pi Zero

November 25, 2015 by Brian Benchoff 329 Comments

Rumors about a new Raspberry Pi have been circulating around the Internet for the past week or so. Speculation has ranged from an upgraded Model A or compute module to a monster board with Gigabit Ethernet, USB 3.0, SATA and a CPU that isn’t even in production yet. The time is now, and the real news is even more interesting: it’s a $5 Raspberry Pi Zero. It’s the smallest Pi yet, while still keeping the core experience.

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