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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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?

Keeping The LiPo Smoke Where It Belongs

November 28, 2015 by Rud Merriam 16 Comments

Nothing brings joy to a hacker’s heart like taking a cheap gizmo and making it useful. Over at Hackaday.io [AndyHull] popped open some cheap LiPo battery power packs to see if he could power a Canon Powershot camera. The entire shebang would be left in the wilderness for photography so keeping it inexpensive was a big goal since it might be destroyed or lost.

The power packs [Andy] looked at have a TP4221 controlling the charge cycle for up to four 18650 LiPo cells connected in parallel. The controller also boosts the voltage to 5 volts for one or two USB ports while providing automatic shutdown if the LiPo cell voltage drops below 3.2v. Below that voltage the cells can be damaged and might possibly cause a fire.

The packs [Andy] used also had a torch output to drive an LED almost directly from the cells. That output is a nominally 3.8 V at 100 mA which is just what he needed to power the Canon Powershot. It could be used to power small micros or other low power devices.

The LED was removed and replaced by a connection to outside the pack. The torch output is triggered by two quick presses on a switch that was also replaced with a connector to allow remote control.

If you’re looking for powerful battery options, give LiPo a try and have a look at [Andy]’s LiPo battery safety issues post, also on Hackaday.io. For a broader LiPo overview, see this obsessive rundown of various batteries.

Byte Magazine Nostalgia Photo

November 26, 2015 by Rud Merriam 28 Comments

Those of us who remember when microprocessors were young also recall the magazines of the era. Readers bought the magazine for content but the covers attracted attention on the newsstand. In the late 70s until the early 90s the competition was fierce, so great covers were mandatory. The covers of Byte magazine created by [Robert Tinney] were detailed, colorful, and always interesting.

[Bob Alexander] of Galactic Studios recreated one of those hand drawn covers using photographic techniques. The cover shows a steam engine, tender and caboose rolling along the traces on a PC board amidst a landscape populated by resistors, capacitors, and integrated circuits. The photographic clone recreates that image using all real components, including an HO train. The circuit, unfortunately, isn’t of a working device.

Creating this work followed all the normal hacking steps for a PC board: a mockup of the layout, designing the board, and ordering it from China. Component procurement was sometimes a hassle since some are no longer in production. The components that weren’t found on EBay were hacked.

The only image manipulation involved the HO train. It was much larger than the PC board so could not be put in place for the photo. Images of the PC board and the train were merged using software. Also added were smoke rings puffing out of the locomotive’s smokestack.

The photo is a worthy recreation of [Tinney’s] original.

For more trainy goodness, check out our own Brian Benchoff’s tour of the Siemens Model Train Club. Or for further photo-realistic modelling, have a look at this insanely detailed Ford pickup model.

Hardware Hacker’s Black Friday / Cyber Monday Guide

November 25, 2015 by Rud Merriam 16 Comments

Between Black Friday, Cyber Monday, and, apparently for some just because it’s a long holiday weekend, hacker-licious sales abound right now. Here’s a run-down gathered from our intrepid Hackaday team who spared little effort in gathering this information. After all, being the hub of hackerdom, everyone just tells us this stuff. Be sure to check the actual details on the site because after reading about all these awesome opportunities to stock up for winter projects, our head is spinning. What to buy? What to give?

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DOE Announces A High Performance Computing Fortran Compiler Agreement

November 21, 2015 by Rud Merriam 21 Comments

The U.S. Department of Energy’s National Nuclear Security Administration (NNSA) and its three national labs this week announced they have reached an agreement for an open-source Fortran front-end for Higher Performance Computing (HPC). The agreement is with IBM? Microsoft? Google? Nope, the agreement is with NVIDIA, a company known for making graphics cards for gamers.

The heart of a graphics card is the graphics processor unit (GPU) which is an extremely powerful computing engine. It’s actually got more raw horsepower than the computer CPU, although not as much as many claim. A number of years ago NVIDIA branched into providing compiler toolsets for their GPUs. The obvious goal is to drive sales. NVIDIA will use as a starting point their existing Fortran compiler and integrate it with the existing LLVM compiler infrastructure. That Fortran, it just keeps chugging along.

You can try out GPU programming on your Raspberry Pi. Yup! Even it has one, a Broadcom. Just follow the directions from Raspberry Pi Playground. You’re going to get your hands dirty with assembly language so this is not for the faint hearted. One of the big challenges with GPUs is exchanging data with them which gets into DMA processing. You could also take a look at [Pete Warden’s] work on using the Pi’s GPU.

Still wondering about the performance of CPU vs GPU? Here’s Adam Savage taking a look…

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