RAREblog

You can start bidding for a numbered Raspberry Pi beta board tonight! The two highest numbered boards go on auction on eBay at 10pm. More boards will be auctioned, with board number one the last to be offered. Details  here .

The Raspberry Pi team are taking a well-earned break over Christmas, but they've left a few more snippets to keep us happy. New photos , a facelift for the Forum, and an informative update to the About page . Let's hope the testing of the beta boards continues to go well. I'm still hoping for the limited edition auction before the end of the year, and a chance for everyone to buy one in in January!

You can see one of the first Raspberry Pi beta boards booting on the RasbPi website.  Amazing Video performance. It looks as if there's an easy-to-fix issue with the current layout. Liz has promised us more info tomorrow. The testing is going well, and with any luck we'll see the first few boards auctioned this year. Fantastic! Congratulations, Pi cooks. Have an excellent Christmas.

The Raspberry Pi site has pictures of the first populated (beta) boards. If all goes well, ten of the boards will be auctioned this year, with production boards hitting their on-line store in January.

The Gertboard is coming - a capable, inexpensive expansion board for the soon-to-ship Raspberry Pi. The Gertboard is will make it much simpler to interface the Raspberry Pi to the outside world. It provides  access to the Pi's GPIO pins, and can include a motor driver. Gert van Loo of Fen Logic Ltd , the board's designer, will publish all the design documents once the design is stable. Raspberry Pi expect to sell a bare board in their shop. That means that you'll need to buy the components yourself, program the on-board PIC if required, and solder the components. Since many of the components are SMT (surface mount) you will need to be a proficient constructor to assemble your own board. Gert hopes that someone will start making per-build boards. I suspect there will be quite a market once the Pi starts to shop in volume next year.

I've just started using the Open Bench Logic Sniffer . It's a very capable bit of open source hardware and it's supported by a highly functional Java client. Together they give you have access to the features of a commercial logic analyser at a fraction of the price. In the UK the board costs just under £50 including VAT. The software is free. There is one minor pitfall, though. The product's home page has a prominent link to the original SUMP client. That takes you to an old version which is no linger actively maintained - indeed I could not even fire it up. There is an actively maintained alternative which worked straight out of the box. There are also a number of firmware upgrades. I don't yet know if I need to apply any of these; I'll report when I do. The sniffer needs at least one accessory: a cable which connects the board headers to the circuit under test.   A single cable gives you 8 connections; if you want to use 1...

Farnell delivered my Beaglebone this morning. The bone is powered up and running; I'll describe the startup process in a later post. The Beaglebone is compact; the board is about 2.1" by 3.4", although the Ethernet socket protrudes by another 0.1". It comes with a demo image on a micro SD card already in its SD slot; there's a second micro SD card supplied, which I haven't investigated yet. Like the BeagleBoard, the Beaglebone comes with the Angstrom Linux distribution, but you've several other options, including Ubuntu. Unlike its big brother, the Beaglebone has no HDMI socket, so you cannot intereface the bare board with a DVD-I monitor. The bone will soon be supported by a number of Capes ( the Beaglebone equivalent of Arduino's shields), and one of these will provide DVD-I support. As you'd expect, you can connect to your board via the Serial USB link. You can also use SSH or VNC to provide a console or GUI session over Ethernet. Ho...

Raspberry Pi have posted some higher-resolution picture s of bare (unpopulated) boards from their first batch. The images are fascinating, not least because they show the scarily compact BGA connections which will link the main Broadcom processor to the board. There are hundreds of pads in a footprint the size of a postage stamp. The post makes clear that these are not the boards as customers will see them ; the board you get will be sold fully populated, with components soldered on. These images are there to whet our appetite and keep us informed about the march towards shipment.

A few days ago I found an old friend - an Acorn Microcomputer dating back to the late 1970s. You might know it by its later name of Acorn System 1. It's arguably the great-great-grandfather of Raspberry Pi ( though several orders of magnitude less powerful). Acorn fathered ARM , whose design lies at the heart of RasbPi's processor; the processor is made by Broadcom , who also trace their ancestry back to Acorn. The Acorn Microcomputer has an led display, a keyboard, a 6502 processor, 512 bytes of rom and an amazing 1k of ram. The monitor (a minimalist operating system) lives in rom; programs can be saved and then reloaded using a cassette recorder. It will run off a 9v battery. Somehow I've managed to hang on to its documentation, though you'll find a lot more information, and an emulator, on Mike Colishaw's website . I've done nothing with this early micro for years, and I'd pretty much decided to give it to a museum. I suspect it still works, th...

Not only do we have a new version of the Arduino software, but the hardware has new retail packaging . Italian style at its best. Congratulations! And Kudos to the designers .

Raspberry Pi have just released pictures of the first batch of  PCBs for Raspberry Pi. This amazing £25 system on a chip should be shipping in low volume before the end of the year. It's built up a huge following already, and the initial production run of 10,000 is likely to sell out fast. The pictures of the PBC layout were amazing, and the actual PCB is just as remarkable. The computer has the potential to change IT education, in this country and elsewhere, but much of its value lies in the way that it's motivated the community. The open source movement has shown that there is a huge pool of talented, motivated people who like to share their work. Raspberry Pi is a focus for those of us who would like to share with the next generation of technologists. It's a product for optimists.

Arduino have released version 1.0 of the Arduino development environment. There's a lot of new functionality in the new release, and there are some significant changes. This blog post  talks about an earlier release candidate, but presumably still applies. At the time of posting, the release notes stop at release 23, but that may be fixed by the time you read this. A quick test showed some of the new features, and some of the issues involved in migrating existing projects. The new IDE looks subtly different. Below you'll see a 'verify' button (shown as a tick) which you can use to compile a sketch without trying to upload it. I found that handy when checking the compatibility of existing code. You'll find changes in several libraries. In most cases these are improvements in functionality. Examples: the Serial library is now asynchronous Serial now contains functions for parsing input data the String class is now more efficient and robust the E...

mbed lpc11u24 beta kit I've been using a Python client while developing my mbed USB-based logic analyser , but the pywinusb package only runs under Windows. Since my desktop is now a Windows-free zone, I've been having to Fire up VirtualBox Start up a Windows XP VM Plug a USB connector into the mbed Tell VirtualBox to give the VM access to that USB device and Curse at the fact that I'm restricted to the much slower version 1.1 of the USB protocol I've now switched to a Java package which runs under Ubuntu. Details on the mbed site . The next step should be to do some timings, but I won't be able to run at full speed until the chaps at mbed have finished porting one of the libraries I need to the new beta mbed LPC11U24.

I just re-discovered Let's Make Robots - a site for robot builders to show off their work, exchange ideas and learn from others. It looks like a great resource with a friendly community. If you're a robot-builder, take a few minutes to register and post details of your robotic creations.

Soft robots keep popping up (or slithering along) all over the place. I'm beginning to think I ought to take a closer look at the technology in my copious free time. I wonder how well a combined crawler/gripper would function underwater.

I've just realised that I placed a couple of posts on the BeagleBoard over on my  Application development blog , when I meant to post them here. I won't cross-post, but here are the links: Busy with the BeagleBoard  and  Blogging from the Beagleboard . Together they give a bit of background to some of my later posts.

While working on the mbed logic analyser , I realised I had run out of USB ports on my workstation. A quick search on Amazon suggested this D-Link DUB-H7  7-port USB 2.0 Hub . I ordered one and it arrived today. Nothing earthshaking, but it works well, looks nice and is reasonably priced. Recommended.

My black Friday Pololu order arrived this morning. I'm delighted with the purchase, and one item in particular has blown me away. It's a MiniMU-9 , which combines a triple-axis gyro, a triple-axis accelerometer and a triple-axis magnetometer. In other words, it measures all the data you need to work out the position and orientation of a mobile robot. And it's tiny. To give you a feeling of its size, the connector holes in the image are 0.1" apart, and it weighs just under a gram. Now if only I had a small, low-cost lightweight, Linux-capable board to control it, I could build an autonomous blimp. But that's just Pi in the Sky  :) Seriously, the Raspberry Pi (described in the Register article linked to above) is well-suited to the job of managing an autonomous blimp. It's true that the gumstix is even smaller than the Pi, and available this month rather than next; but it costs a lot more. Meanwhile I have projects stacked up that will keep me occu...

LPC11U2 mbed I'm making steady progress on my Logic Analyser project for the new beta version LPC11U24 mbed . So far everything has worked as it should, although one or two libraries are still being ported to the new device. I can already send the state of an 8-bit wide set of mbed inouts to the PC over a USB HID connection. I have now idea how fast the final version will be, but it should be able to analyse fast  (400kHz) I2C and some SPI interactions in real time. Hendrik Lipka (another mbed user) suggested that I might adapt the open-source SUMP client  so that it can capture, analyse and display data on the PC. That's an exciting idea which I will certainly follow up.

If you're a creative developer with experience of the Qt cross-platform framework , you just might get a free Raspberry Pi Linux-based microcomputer courtesy of Nokia. (If you're unfamiliar with this credit-card sized wonder, this video will give you a great introduction). Nokia are looking for people who will   port software, develop apps, and test and improve the Qt 5 Linux stack. They are so keen that they have funded 400 vouchers for Raspberry Pi. If you have a visible track record as a Qt developer, and a good idea for a relevant project, head off here to find out how to apply for a voucher. Last time I looked there were 65 applications for those 400 vouchers, so hurry along!

mbed nxp LPC11U24 I'm having great fun with the new mbed . Just working my way through the examples so far, and everything is working well. The photo show the mbed pretending to be a USB mouse. I'm looking forward to getting stuck into my logic analyser project ; once that is finished I may hook the mbed up to my pseudo-microwriter and turn it into a USB device.

I mentioned a few days ago that a new mbed was on its way . It's still in beta, but I was lucky enough to be selected for the beta program and I am starting work on my project . First impressions are very positive: the instructions on the mbed site are very clear. It took about two minutes to use the cloud-based compiler to create the obligatory led blinking program and then drag the binary file over to the mbed. Now to work through the examples and test it out as a USB device.

Like many US retailers, Pololu are offering massive Black Friday discounts on a range of their robotics products. Some of the bargains: 33% off the m3pi mbed- based mobile robot (you will need to get your own mbed) 50% off a pair of wixels 30-60% off various motor controllers 40% off the MinIMU-9 Gyro, Accelerometer, and Compass The last item looks perfect for an autonomous vehicle/aircraft navigation system. There are also flat discounts available, depending on the size of your order; these can be combined with the individual product discounts. I just saved $150 on a $350 order. One thing to take into account: if you're buying from outside the USA you will have to pay local taxes and a processing fee to the shipping agent when the goods arrive. The offer is time-limited, and will expire  at 11:59 PM PST on Monday, November 28 (7:59 AM GMT on Tuesday, November 29).

Yesterday Google hosted a qualifying tournament for the Bay Area First Lego League ( FLL ) at their Mountain View Headquarters. Imagine the excitement of the 9 to14 year-olds as they arrived at Google headquarters. They will remember the event for the rest of their lives, and who knows what they will achieve in the years to come. At a time when news is full of economic gloom, it's great to see the excitement and creativity of the young, who are living at the start of a golden age of maker technology.

image courtesy GreenArrays, Inc. GreenArrays have announced the GA144, a low-energy processor with 144 cores. It's not cheap, as the minimum order is for 10 $20 chips, and the development board is $450 dollars, but it's of great interest to me; next year I will need some real processing power for a neural-network robot I am working on, and this looks as if it would be ideal. Robotics enthusiasts will probably be familiar with the Parallax propeller , an inexpensive multi-cored processor that is desgined for hobbyist use. The propeller is an affordable introduction to parallel processing, but the GA144 offers a couple of orders of magnitude more processing power and is very energy-efficient. The chairman of GreenArrays is Chuck Moore, the inventor of Forth. The GA144 supports arrayForth, a powerful language for parallel computing.

A few days ago I mentioned the new Raspberry Pi stickers which sold out as soon as they were on offer. The Raspberry Pi team ordered a second batch, but these took longer than expected to arrive. It's heartening to read people's reactions to the apology  for the delay. You can see that there is huge commitment to the project from supporters around the world. Raspberry Pi is potentially world-changing, and I think the foundation will be astounded and delighted by the strength of the effort to create free software to help this fantastic product achieve its promise. And remember - while we're waiting for the Pi itself o get through QA, you can support the foundation by ... buying some stickers :)

I've just heard that I have been accepted for the beta test program for the new mbed cortex-m0 . I'm going to build a logic analyser which transfers data  via the USB interface to a PC for analysis and display. While one can do this using the existing mbed and serial communication's, I think the USB approach should support significantly higer data rates. I've set up a new project page in my notebook at mbed.org. Comments and suggestions welcome!

Bluebot-L We learn by our mistakes, but it can be cheaper and less painful to learn from the mistakes of others. Here's one of my mistakes; I hope the story will save you time and money. A few months ago I started work on a wheeled robot based on Veroduino - an Arduino clone build using Vero strip board. I had a wheeled base which contained a couple of geared motors. They drew a fairly low current so I decided to use a TC4427A h-bridge controller on a shield-like board that sat atop the ATMega326 micro controller. I decided to use separate power supplies for the controller and the motors;  I bought a couple of battery holders, each taking 4 AA cells. I used foam plastic for the base; it's easy to cut and drill,  and it's lightweight, but strong enough for the job (so long as it isn't crushed). Construction was rapid and I soon got to the point where I could try it out on a simple line-following exercise. Disaster! The b...

Windows for Devices just published an article suggesting that a recently launched product from Embest and Farnell was taking on the BeagleBoard xM. The  DM3730-EVK from Farnell is based on a TI DM3730 chip - a Corterx A8 with DSP capability. It comes with 512Mb of flash and 512Mb of RAM; the kit also includes a 4.3" screen. Out of the box it boots linux or WinCE. It's priced at £353.00 + VAT. The BeagleBoard has 512 Mb of RAM and the same TI chip; LED screens are separately available, as is WinCE. It costs £124.80 + VAT. A touch screen might add another £120 to that. However, there's a more fundamental difference between the products. The DM3730-EVK is clearly aimed at the commercial market. It seems to be a stable design which you could sensibly use as the basis for pilot (small-scale) production of a commercial product. The Beagleboard explicitly warns that it's not intended for production use, largely because the team reser...

Soft actuator: DRL, CSAIL, MIT One of the members of Premier Farnell's element14 has just posted about a soft robot which uses hydraulics to move around.  (The post suggests there are chemical reactions involved, but that doesn't seem to be the case). The picture shows an actuator like those used to move the robot. If that's not scary enough, you can watch a video . I find the snail-like creature rather scary; it wouldn't be out of place in Doctor Who. Luckily it moves so slowly that escape would be fairly simple, unless you're surrounded by the beasts! The original poster cited a paper on the Distributed Robotics Laboratory Wiki . You'll find many other fascinating robotics projects described there. It's a great place to look for inspiration if you want to start a robotics  project that would really stand out.

mbed (courtesy of NXP) Last year marked the debut of the mbed - an ARM-based System-on-a-chip from NXP in a compact 40-pin DIL format. I was lucky enough to be selected to do a road-test for Farnell's element14 . The mbed is an amazing product. One of its great strengths is the large support library which includes code developed by the mbed team and by its users. With I2C, SPI and Serial suport, and a full set of GPIO pins, it's easy to interface to external devices, and the web-based compiler means that you can program the device within 5 minutes of opening the box. Now a second mbed is in beta-test. Based on the NXP LPC11U24, it    is designed for prototyping USB devices, battery powered applications, and 32-bit ARM Cortex-M0 designs. I'm hoping to get my hands on one soon and will report in due course. The original mbed is still selling well, and is available from Farnell for just under £40 + VAT.

People have been speculating about what young users will do with something like Raspberry Pi , the $25 dollar computer. Here's a clue from TED . I've had lunch with two friends in the last couple of days. Both have children at school. Both  really warmed to the idea of Raspberry Pi. They're optimistic that it would encourage their children to program, rather than just play games and hack visit social networking sites. I can guess what the young may be getting from Santa this year.

Oomlout have come up with a neat design for a (nearly) free project box for Arduino . It's printed on 210 gsm card stock; you print it, cut it, fold it, and voilà - a simple but functional home for your Arduino creation. I'm working on a project right now that could use one of these. I'll pop out for some card stock and have a go. Update : My local Stationers (WH Smith) have packs of white 220 gsm card stock for a little over £3 , and they also have mixed packs of coloured card. So you can make yourself a coloured project box if you want.

I ordered stickers from Raspberry Pi , and they arrived this morning. Like their namesake they are fully functional but very small. While you're waiting for a chance to buy the real thing, drop by their on-line store and buy a sticker!

I've pushed my Beagleboard Python I2C library up to GitHub, along with the sketch I used to create an  Arduino I2C slave that drives an LCD. (A slave driver?) It's in a public repository at git@github.com:romilly/beagleboard-i2c.git This is alpha code; the API will change;  the code may not work and/or may do bad things. Use it at your own risk. More coming soon. (Stop press: that will include a non-blank README ) If you aren't familiar with Git/GitHub,  there is good reference material here .

Robot Electronics offer a very nice 20x4 LCD display with I2C/Serial interface for £19.99 + VAT. I've hooked it up to an Arduino; it's easy to drive and looks very professional. I stumbled across Robot Electronics while searching for LCD suppliers. It turns out that they are the on-line trading arm of Devantech, whose Ultrasonic Rangers are widely used in Robotics Projects. Their full range of products is much wider than that, and their  on-line shop is well worth a visit.

Raspberry Pi Raspberry Pi have just published the final artwork for the board . It's fascinating (and rather scary) to see how they have managed to compress a linux-capable System-on-a-chip onto a board the size of a credit card. The first boards are expected in December; meanwhile, if you'd like to help test their online shop you can buy a Raspberry Pi sticker .

Arduino Bots and Gadgets is a step-by-step guide to building, adapting and designing prototypes based on the Arduino family. It's published by Make magazine - a member of the O'Reilly Family. Like Make, the book delights the eye. Readers are drawn into a programme of exploration and discovery which will help them develop the skills they need to start prototyping their own inventions using the Arduino Platform. The authors write clearly and the projects look fun to build: a Stalker Guard an Insect Robot an Interactive Painting a Boxing Clock a Remote for a Smart Home, and a Soccer Robot I have one niggle: the first project uses an Arduino Nano, rather than the Uno which is mentioned at the start of the book. Readers might feel a little miffed if they'd bought the Uno only to find they needed another variant. That's a minor complaint, and my overall reaction to the book is very positive. The book is clear, attractive, authoritative, and (at nearly 30...

We're seeing a great and welcome upsurge of interest in introducing school children to programming, rather than just teaching them how to use Powerpoint, Word and Excel. Jason Gorman got programmers and teachers together at Bletchley Park this Summer to look at ways of bringing programming into Schools RaspberryPi , inspired by the success of the BBC micro in the '80s is aiming to fire up the next generation of school-age programmers the Arduino, along with introductory kits like Oomlout's experimenters kit   has made the Internet of Things accessible to beginners of any age MIT's  Scratch has children and adults creating their own interactive stories, games, music and art And now there's Minibloq . Minibloq The Arduino blog recently announced Minibloq v0.8 - a visual programming environment for the Arduino. It's aimed at    the creative at heart non-programmers , and I couldn't resist a play. (I leave it to those with whom I've deve...

I've just been enjoying   A Curriculum of Toys - an article in Make Magazine by Saul Griffith . (Thanks to  +Limor Fried  for the link). Griffith examines the ways in which children can learn from toys. He lists the skills that great toys can help to develop, and looks at activities which foster those skills. Play is a core part of learning, and good toys promote good play. On Sunday mornings, years ago, my daughter Alex and I would steal quietly downstairs to listen to music and build things. We started when she was two, building things with sticklebricks, then moved on to duplo and  LEGO. She and I are convinced that those Sunday mornings played a part in fostering her Maker skills. If you want to see what she's made with them, take a look at Let's Get Prehistoric . Some people dismiss play; they consider it at best a break, at worst a waste of time. Saul Griffith takes the opposite view. Play helps us, as children and as adults, to develop, ...

You can now pre-order the BeagleBone at Farnell UK, or ask to be notified when it's available. With availability expected in mid-November, you shouldn't have long to wait. The BeagleBone is a hardware hacker's dream, with a compact format, low power consumption, plenty of I/O and enough processing power for serious real-time computation. If you want to interface with the world outside, connecting to sensors and drive LEDs, motors and relays, the BeagleBone has the capacity to do it. The BeagleBone has stirred up a lot of interest, and the first shipment is likely to sell out fast; if you want to get your hands on one, pre-order today!

The BeagleBoard is now chatting happily to a boarduino over I2C. I'm running my simple Python script on the BeagleBoard and text is appearing on the boarduino's LCD. I switched to the boarduino because I had one sitting in  a drawer, and I knew from earlier this week that a 16MHz ATMega328 could handle the BeagleBoard's fast (400kHz) I2C. The boarduino is designed for use with a prototyping board, and it has a very compact form factor. I'll probably transfer boarduino and LCD to a semi-permanent strip-board home. The BeagleBoard can rest for a day or two; I'm working on TrackBot, sorting out the Radio problem that I encountered earlier in the week and adding a Pololu IR proximity sensor to help avoid damaging collisions. After that it will be time for a retrospective review, and I can start planning B4 - the BeagleBoard Based 'Bot.

Update: The first batch of stickers sold out in 24 hours! More are on their way, and you can pre-order the stickers (but not the Pi!) from the website. A lot of people are getting very excited about the imminent launch of the Raspberry Pi . It's an ultra-low cost Linux-capable board based on an ARM11 core, and it's due to go on sale in December. If you want a quick overview of the Pi and what it can do, this video on the foundation website is a good place to start. The Raspberry Pi foundation expects strong early demand from hobbyists, but the longer-term aim is to attract new users at school level. Since the Pi is to sell for about £20-£25 that looks realistic. You can't pre-order the Pi , and should beware of sites offering the Pi: they are trying to part you from your money. You can help to test out the new on-line shop and contribute to this very worthwhile project by purchasing a Raspberry Pi sticker . You'll end up paying a little over £3, most ...

A lot of useful work today, and a valuable discovery, but I haven't quite got to where I want to be yet. I'm trying to use an Atmel ATMega8 on a DT107 board from Dontronics as the middleman, sitting between the BeagleBoard and the LCD display I want to drive. It took a while to wire up the DT107 to the LCD. To find out about what connects to what, I had to look at  the Oomlout instructions , an Arduino Pinout , the ATMega pinout, the DT107's schematic and the layout of the SimmBus. I'm fairly sure I've got the connections correct but the Beagleboard is complaining about an error on the I2C bus. That part of the wiring is easy to check, so I think the probblem is more fundamental. The DT107 board I'm using has an ATMega8 with an 8Mhz crystal. It just may not be able to run I2C at 400kHz, which is what the BeagleBoard I2C-2 interface uses. On the plus side, I discovered that you can use the Arduino development environment with an ISP to program a ...

The BeagleBoard can now drive an LCD display via I2C, using an Arduino as an I2C slave. The Arduino sketch is a slightly tweaked merge of two examples: the LCD driver and the I2C slave. I've written the BeagleBoard driver in Python. It's really simple. It uses my generic I2C class, which is also very straightforward. For now, here's the Python code for the LCD Driver. #! /usr/bin/python import i2c, time FF = '\f' # Form Feed class LCD: def __init__(self, address): self.lcd = i2c.I2C_device(0x04) def pr(self, ch): self.lcd.begin_transmission() self.lcd.send(ord(ch)) self.lcd.end_transmission() def prints(self, string): for ch in string: self.pr(ch) def clear(self): self.pr(FF) lcd = LCD(4) lcd.clear() lcd.prints('Hi from BB') time.sleep(2) lcd.clear() lcd.prints('Hello again') It uses my generic I2C class, which is also very straightforward. I'll put all the code up on GitHub real soon now.

I want to revise the design of my I2C-based LCD board. The old design works, but it's not reliable and it puts a lot of traffic on the I2C bus. I'd prefer something that created less traffic and placed fewer demands on the host. I2C is a great protocol for connecting sensors to micro-computers, but you can also use it to link two  computers together. The solution that I'm looking at will use an Atmel 8-bit AVR  processor to drive the LCD and act as an IC2 slave. That way the host computer needs to send just two bytes down the wire to write a character. The current design sends three or four times that many. I'm going to develop the solution in small steps: Get the BeagleBoard talking to an Arduino over I2C with BB as master and Arduino as slave. Connect the Arduino to the LCD. Add LCD driver code to the Arduino sketch, and control it using I2C Put an ATMega8 in a DT104 board from Dontronics. I have several of each spare. Program an arduino bootloader into th...

Yesterday was frustrating but instructive. I started testing the radio link to TrackBot. At a minimum I want to create a dead man's handle to prevent the robot from careering into a wall. Some control over direction and speed would also be useful. I'd set up an arrangement like this a few year back using a LEGO base and an AVR conrtoller. I kept the hardware but I was a bit lazy about project notes in those days. However, I knew that I'd been able to transmit commands from a Laptop to the AVR and I still have the receiver, the trnasmitter, and the hand-wired RSR232 cable and connector that I used to send sigmals from the Laptop. I spent hours trying to get the arrangement working with Trackbot. I could detect when a character was being transmitted, but it wasn't being sent correctly. Usually this is a baud rate, frame length or parity issue, but not this time. I checked and rechecked code and comms settings, but to no avail. Time to try the Bus Pirate. The ...

I've taken a break from the beagleboard and have been working on TrackBot - a tracked robotics prototyping platform. The first iteration is complete; TrackBot now moves under program control. It's running a simple test program which turns left, turns right, then moves forward and back, stops, turns a led on and then repeats the cycle. More ambitious behaviour can wait until I have a proximity sensor working; strip-board is fragile and I don't want TrackBot to break itself by running into furniture or a wall. TrackBot is built from a Pololu RP5 base (now sadly discontinued by Pololu, but still available from Active Robots ). The base is controlled by a Solarbotics L298 compact motor drive r; that in turn is controlled by an Arduino Pro Mini 328 (5v/16MHz) . The next iteration will be to link up radio control. I've already mounted an old 433.9 MHz radio receive r, but it's not yet connected to the Arduino. After that I'll add proximity sensing (using ...