BeagleBone ARM development kit announced

The creators of the BeagleBoard low-cost ARM-based computer have come up with a new device which drives down both the size and the cost, while providing an interesting stop-gap solution to those waiting for the Raspberry Pi: the BeagleBone.

Built around a Texas Instruments AM335x ARM Cortex-A8 microprocessor running at up to 720MHz, the BeagleBone promises over 1,400 Dhrystone MIPS and the ability to run a fully-featured GNU/Linux distribution.

The tiny package also includes an OpenGL ES 2.0 compatible 3D graphics accelerator, a USB 2.0 host port, microSD connector for storage, gigabit Ethernet, a multipurpose USB device connection featuring on-board hub, USB-to-serial and JTAG conversion with software reset, and a reprogrammable high-speed USB device interface, along with two 46-pin two-row 0.1-inch spaced female expansion headers using 3.3V IO.

Despite all these impressive features, the BeagleBone fits in the palm of your hand – and in doing so takes up little more room than an Arduino microcontroller at an impressively compact 3.4″ x 2.1″. In addition, the BeagleBone will support ‘capes’ – equivalent to Arduino ‘shields,’ minus the awkward pin spacing – to easily add more hardware to the platform.

As standard, the BeagleBone will come with a pre-installed copy of the Maemo-based Angstrom Distribution, node.js and the Cloud9 IDE on a 2GB microSD card, which will combine to allow developers to quickly and easily upload new code to the board using a single USB connection for data and power.

“We’re big fans of embedded systems at our office and think Cloud9 IDE for BeagleBone is an amazing use case. It makes writing code for your device as easy as plugging in and connecting to a port with a browser,” claims Rik Arends, chief technology officer at Cloud9 IDE. “We’re looking towards supporting embedded development from the cloud in the future. This way, our users will have all the benefits of keeping code safely online, with the ability to easily distribute to multiple devices.”

The BeagleBone is due to hit the usual suspects in the US before the end of the month, priced at $89, with UK stockists yet to be confirmed. To whet your appetite, there’s an introductory video below, and more information is available on the BeagleBoard site.

The RHT03 digital temperature and humidity sensor

RHT03 Digital Temperature and Humidity Sensor
RHT03 Digital Temperature and Humidity Sensor
Accurate but expensive - the RHT03.

While the use of analogue sensors for detecting temperature are common in the world of open source electronics, digital devices are less so. The RHT03 could help change that, offering a low-cost high-accuracy sensor which connects easily to most prototyping platforms.

The first thing to notice about the RHT03 – also known as the DHT-22 – is its breadboard-friendly layout. Mimicking a T-style package, the legs are properly spaced for connection to any common breadboard type, while also allowing for the component to be soldered to a through-hole PCB for a more permanent project.

Sadly, the RHT03 is clearly made on a budget: the legs are extremely thin, and it can be fiddly to get the breadboard to accept the component without bending one or all. If you’re using the RHT03 in a project where it’s going to be frequently moved around, consider adding some reinforcement.

The RHT03 is an odd beast: although digital, it’s not a One-Wire device and doesn’t work with any common libraries. Thankfully, resourceful hackers have fixed that problem: a GitHub project page provides a simple library for the component plus sample code which spits out the current temperature and humidity.

There are limitations, however: query the RHT03 too quickly and it will return an error, something which is never a problem with an analogue sensor. That restriction – due to the digital nature of the device – comes with an corresponding upside: unlike a thermistor, there’s no complex calculation to carry out in order to arrive at a human-readable figure.

Connecting the RHT03 to an Arduino and running the sample script results in two figures: temperature in Celsius and humidity as a percentage. Using a calibrated multimeter with K-type temperature probe proved that the temperature was accurate, and the humidity didn’t seem far off. Accuracy is official stated as ±0.5°C and ±2% RH.

Compared to using two separate components, the RHT03 has a dual advantage: the sensors are located together for better accuracy, and it requires only a single input pin on your controller along with VIN and ground connections. It’s also battery-friendly, drawing around 1.5mA when reading and 50µA when in standby mode.

If you’re using a non-Arduino prototyping platform, the RHT03 will likely still work – thanks largely to a wide supply voltage range of 3.3-6V – but you may find yourself doing a bit of hacking in order to implement the DHT22 communications library.

There is a catch in all this, however: at £8.51, the RHT03 is an extremely expensive option compared to analogue sensors. If you need accuracy, it’s a good option, but be prepared to pay for the privilege.

Pro: Accurate temperature and humidity readings from a single pin.
Con: Very expensive compared to analogue equivalents.
Supplier: Proto-Pic, £8.51
Score: 6/9

The Arduino ProtoShield v5

ProtoShield v5 Clone
The breadboard fits perfectly on the ProtoShield.

Arduino ‘shields’ – add-on boards that connect to the Arduino’s headers to add additional capabilities – are handy things, but sometimes you need something a little more custom. Although it’s possible to make your own, the Arduino’s famously non-standard pin spacing makes it difficult, but there’s a solution: the ProtoShield.

As its name suggests, the ProtoShield is a shield which makes prototyping on an Arduino significantly easier. Often supplied in kit form, the ProtoShield’s design is open source. As a result, it’s possible to get the device pre-made from a variety of sources, which sadly means you’re often taking a gamble on quality unless you buy directly from a reputable supplier.

The shield on test, unfortunately, is from no such source: manufactured by an unknown Chinese OEM and sold through Hong Kong gadget site DealExtreme, the design is based directly on Adafruit’s implementation of the ProtoShield with the logo removed before the PCB has been printed. That’s in direct contravention of the Creative Commons licence under which the open source design is provided, and we’d recommend you look elsewhere if you’re planning on buying one.

The shield itself arrives as two separate components: the ProtoShield, plus a mini-breadboard with an adhesive pad on the underside. This breadboard is specifically designed to fit on top of the ProtoShield, allowing you – if you so choose – to combine the two into a portable prototyping platform.

The other option is to use the mini-breadboard on another project, and concentrate on the ProtoShield itself. The PCB is covered in through-hole soldering points, and a glance at the underside reveals a combination of connected and disconnected circuit paths. There’s room for a wireless module, an SOIC solder pad, and in addition to the usual Arduino headers there’s an additional five for ground and 5V on many designs.

The concept is simple: prototype the layout of your custom shield’s components with the breadboard, and when you’re ready solder the components in place directly onto the shield to create a permanent custom creation. It’s a neat idea, but there’s a problem: the ProtoShield isn’t cheap. Even as an unlicensed knock-off shipped from China, the ProtoShield will set you back around £7, which compares poorly with some stripboard and a set of angled headers.

As a prototyping platform using the stick-on breadboard, however, the ProtoShield is great. If your project calls for LEDs, you’ll be pleased to see two already form part of the shield’s design, along with a handy switch. The fact that the reset switch is brought to the top is also a welcome sight, as many shields forget how inaccessible the Arduino’s version can be when the shield is in place.

Pro: It’s a great portable prototyping platform when combined with the breadboard.
Con: While easy, it’s an expensive way to make your own shields.
Supplier: DealExtreme (uncredited clone of Lady Ada’s ProtoShield)
Score: 7/9

Building stripboard prototyping modules

Robotics enthusiast and Arduino hacker June Jones has posted a guide to creating a infrared sensor module for a line-following robot which also serves as a handy guide to building homebrew sensor modules for any prototyping system.

While the guide, published over on Instructables, starts off with the familiar sight of a breadboard and an Arduino, once the initial prototyping is complete Jones demonstrates how to turn a breadboarded design into a tiny module using stripboard.

Although not as impressive as a professionally etched PCB, stripboard is handy stuff: Jones shows the design shrinking from a hefty breadboard down to a tiny module which can be plugged in to any Arduino-like prototyping system with ease.

If you’ve ever wondered how to take a breadboard concept to the next level, you could do a lot worse than follow the guide – even if Jones does admit that the stripboarded version stopped working after a short while due to a component fault.

Stories in analogue IC design

If you’ve ever considered the insides of those magic black boxes at the heart of many electronics projects, then you’ve likely thought that they must be beyond the ken of mere mortals.

Don Sauer’s site Idea2IC looks to change all that, with a series of fascinating tales from his 30 years in the analogue and mixed signal integrated circuit design business.

From his first sixteen-pin IC design – the LM13700 stereo transconductance amplifier, “designed by Bill Gross and myself in less than 5 minutes” – to more modern creations, Sauer’s site is a goldmine of tips, tricks and fascinating anecdotes.

For those looking to make the leap into IC design, Sauer’s Spice simulations are well worth a look. For everyone else, just marvel at the thought process that gives birth to those little black and silver bugs.

Andrew ‘bunnie’ Huang on the future of the open hardware movement

Noted hacker, maker and author Andrew ‘bunnie’ Huang has made an interesting prediction: the best days of the open hardware are still ahead of us.

In a reasoned and thorough blog post, Huang revisits the subject of a talk he gave at the 2011 Open Hardware Summit earlier this year: that of the future of open hardware.

“Currently, open hardware is a niche industry,” Huang admits. “In this post, I highlight the trends that have caused the hardware industry to favor large, closed businesses at the expense of small or individual innovators. However, looking 20-30 years into the future, I see a fundamental shift in trends that can tilt the balance of power to favor innovation over scale.”

These trends – including a point in the next few decades where we reach a fundamental limitation beyond which it will be impossible shrink semiconductors – will, Huang argues, lead to a return to the open hardware ideals of the consumer electronics industry’s early days.

“In the beginning, hardware was open,” Huang reminds us. “Early consumer electronic products, such as vacuum tube radios, often shipped with user manuals that contained full schematics, a list of replacement parts, and instructions for service. In the 80s, computers often shipped with schematics.”

As the race to create newer, faster, smaller components slows down, Huang argues, devices like tablets and smartphones will become inherently more open. Users will be able to drop in new processors and memory modules, much as they do with a desktop PC – one of the most ‘open’ of the proprietary hardware platforms around – or an Arduino.

Huang’s full blog post on the subject is well worth a read if you’re at all interested in the open hardware movement.

Hacker turns an Arduino into an oscilloscope

SourceForge user OLeuthold has been hard at work creating an oscilloscope-like device from something many hackers are likely to have lying around: an Arduino Uno.

The lxardoscope project creates a pleasingly oscilloscope-like display on a Linux host system to which the Arduino Uno board is connected. With a resolution of around 3,000 samples per second, the open source project won’t replace a real oscilloscope but is noteworthy for the sheer hackiness involved.

To get a clean signal, OLeuthold explains that users need to remove the ATMega chip from the Arduino Uno board post-programming and insert it into a custom-built circuit which includes a power source with ground set to -2.5V and VCC set to +2.5V.

While it’s a clever hack, some users are questioning the viability of the project as a tool. Comments on a Hack a Day post where lxardoscope was discussed range from incredulity at the poor bandwidth of the psuedo-oscilloscope to unfavourable comparisons to the rather more polished Xprotolab project.

If the naysayers haven’t put you off, the SourceForge project page has full construction details and source code.

Samsung completes LM80 testing on 2323 LED

Samsung’s LED arm has announced the completion of 6,000 hours of IES LM-80-2008 testing on its latest lighting-grade 2323 LED package.

Although the company isn’t publicising the test data, it has declared that it will make the results available upon request. “We realise the importance Energy Star certification plays in regards to utility rebates and are pleased to offer LM80 data to our customers as a guide for expected lumen maintenance,” said chief marketing officer Kevin Kim at the announcement.

The IES LM-80-2008 standard – commonly known as LM80 – is the industry standard method for determining the lumen depreciation characteristics of LED light sources.

Complete test data on the company’s mid-power 2323 LED package – which promises 120lm/W from a 5.29mm² module – will soon be joined by data for the company’s remaining mid- and high-power products.

While your average maker likely doesn’t care too much about standards bodies and official certifications, LM80 data for the 2323 LED packages could tip the balance towards Samsung for those looking to take their creations to commercial production.

The Nanode breaks the 1K barrier

Nanode

Ken Boak, of London Hackspace, has announced that his Arduino-compatible Nanode kit has just passed the 1,000 units sold mark. While that’s not quite at the level of the official Arduinos, it’s certainly not bad going for what started off as a small-scale hackerspace project.

The Nanode is provided as a kit, featuring an ATMega328P with Arduino bootloader and pin-compatibility with existing Arduino shields. Where it differs from the standard design is in the inclusion of an integrated Ethernet connection and a set of screw terminals for a local serial bus, designed to allow users to chain together multiple Nanodes into a local sensor network.

More information on the Nanode project can be found over on the official site.

Arduino Due – ARM meets Arduino

Arduino Due board

The Arduino team had a surprise announcement to make at this year’s Maker Faire: a new design called the Due, which makes the move from eight-bit ATMega chips to a 32-bit ARM-based processor for the first time in an officially licensed product.

Arduino Due boardThe Arduino Due is designed for those who find even the Arduino Mega a little restrictive. Despite retaining pin-compatibility with its predecessors – including the irritating pin spacing that precludes the use of Veroboard and the like without offset stacking headers – it packs in a wealth of new features including:

  • 96MHz 32-bit ATMEL SAM3U Cortex-M3 CPU
  • 256KB of flash memory
  • 50KB of SRAM
  • Five SPI buses
  • Two I2C interfaces
  • Five UARTs
  • 16 analogue inputs with 12-bit resolution
  • 52 digital inputs/outputs

Unfortunately, the Due isn’t available to buy just yet. The Arduino team is running the board through an invite-only beta process, after which pre-release ‘Developer Edition’ boards will be available to buy for those who want a say in the final release.

There’s no word on pricing yet, but as soon as we have our hands on one we’ll be sure to bring you a full review.