RAREblog

I've just published the eBook I'll be using for today's session at SPA. It's called Build your own Arduino clone, and you can get it here . It's a complete set of instructions for building your own version of the Shrimp , as created by the Makers of Morecambe. For the next few days you can get the current version and all subsequent updates for free. You can pay more if you want to. In return, I hope you'll provide me with feedback - and a few tweets wouldn't do any harm. The minimum price will soon be going up to a massive $1.49, so don't wait. Get it today !

Homebrew ZIF ISP This morning I finished off the homebrew In System Programmer (ISP) that I started yesterday. It's now happily burning bootloaders onto the chips I'll be handing out on Monday's SPA session . I'm relieved to find that the installed code includes a blink sketch. That means that the Shrimp-builders will see that their new creations are working as soon as they power them on. I need to prepare 20 chips for the session, plus a couple of spares just in case. At this rate I'll be done by teatime.

I'm working on the preparations for my Monday evening Shrimping session at BCS SPA 2014 , and as always things are taking a little longer than planned. Phenoptix AVR ISP I got an AVR ISP shield from Phenoptix a while back and verified that it would program the chips I need for Monday. It has standard IC sockets, which means that you need to be a bit careful when removing the chips after you've burned the bootloader. If you don't do a straight pull you can bend the legs of the chip and the damage can make the chip unusable. I decided a few days ago that I'd use a Zero Insertion Force (ZIF) socket for the programming. These allow you to drop a chip in, close the gripper of the ZIF, program the chip and then release it. You can then remove the chip easily without any risk of damage. ZIF Socket It's a ZIF socket, Jim, but not as we know it I got a couple of sockets which were surprisingly hard to find in the UK. When they arrived I discovered that they ...

I've a list of about five blog posts that I'd like to finish and publish, but they will have to wait a while. I need to get everything tidied away for next week's diversion at BCS SPA, and there's still quite a bit to do. So - apologies to everyone who demonstrated in the afternoon at the OpenLabTools day, and everyone I met at Southend's Raspberry Jam. I'd hoped to cover your events by now, but don't worry: your time will come :)

Lunchtime at Covent Garden I've just got back from a delightful lunch near Covent Garden with an old friend, Ron Condon. Way back in the early 80s, I was running a software house and Ron was editor of a rising upstart newspaper called datalink . The industry hadn't yet been infested by PR roaches, and I was able to build up a great relationship with one of Ron's reporters. We gave datalink lots of good stories and they gave us lots of good press coverage. Many years have gone by. Ron and I have both retired, and we have both found things to do that keep us busier than ever. Ron now edits contributions to The Analogies Project, which finds and shares analogies that help non-specialists understand issues in IT security. I'm getting more and more worried about the in -security of the Internet of Things. My post-lunch homework is to come up with an analogy which can help the person in the street understand why IoT security matters so much, and why it cannot sa...

is your brainchild going to work? You've built your latest (or maybe your first) Arduino clone. It might be breadboarded , on stripboard , or a PCB . You've visually checked the connections, over and over, and maybe done some quick continuity checks with a multimeter. Everything looks fine. But will it actually work? Follow these steps to check it out. Use blink - The Secret Sauce Here's my secret sauce for building testable clones: Use a chip that has both a bootloader and the standard blink sketch pre-loaded . Use a 5V LED for testing. Let's look at those in a bit more detail. Use a chip that has both a bootloader and the standard blink sketch pre-loaded When you test your clone with a pre-prepared chip, you're starting with a known good core component. If the blighter doesn't blink you know you've made a mistake in the wiring. For more detail on why this is a goo idea on courses, see here . A 5v LED is the tester's friend Many make...

Today I tweeted for advice about the best way to put a bootloader and a blink sketch on the chips I'll be using for the BCS SPA conference next week. (There's still time to book !) Shrimping It! One respondent asked how people could learn to program if the chips already had a blink sketch on them. That's a good question which deserves a full answer, hence this post. But first, some background. I'm semi-retired but over the years I've taught courses about aspects of IT to a lot of adults. I've learned a couple of things that have worked well for me and my students: I make sure everyone starts and finishes with a win , and  I introduce one new idea at a time This approach starts students off by giving them something that's easy to copy and is more or less guaranteed to work.  Then I guide students as they experiment with changes and enhancements until they have mastered all the skills they need. So for the Shrimping lab, students will d...

The Shrimp Farm As you may know I am running a diversion on Shrimping It! at BCS SPA next week . People attending the diversion will be given the kits, and will get to keep the Shrimp they build. I'm writing build instructions in an e-book on LeanPub . I'll be publishing it Real Soon Now(tm), before it's finished, with an initial minimum price of £0. That means that you can get the e-book free and will get all subsequent updates without paying anything more. If you do, please provide feedback and let me know of any mistakes. SPA Shrimp Kit Once the book has been debugged I'll raise the minimum price to 99p, but early customers will still get updates free of charge. The book is detailed enough that I hope you can build your own Shrimp following the instructions. If you want to build a SPA-style Shrimp on you own, you can get just about everything you need from ShrimpingIt ! To my surprise and delight, buying from them will cost less than I paid for ...

Engineering Labs I spend a delightful and stimulating day last Friday at the Cambridge Open Technology Workshop. I was joined by a friend who runs a lab at UCL. I've been trying for a while to persuade him that his teams should build more of their lab equipment. He's always resisted this; the powers that be tell him that researchers should do research, rather than build equipment. Alexandre Kabla Alexandre Kabla's introduction gave a possible solution; why not get undergraduates to work on equipment as part of their project work? There was a splendid example of this approach on display in the afternoon. Morning talks In the morning we listened and learned from a series of 15-minute presentations. At the end of the morning sessions we heard lightning introductions to the afternoon's demonstrations. Alex Bradbury The first morning talk,  The Raspberry Pi as a building block for Creative Engineering , was delivered by Alex Bradbury. This was a great introduc...

School Chapel I lunched in Westminster today with old friends. Three of us have known each other for more than 60 years; the fourth taught us Chemistry over 50 years ago. Another old friend had organised the meeting to celebrate and thank the teacher who inspired us, but sadly could not join us today. Of my three schoolmates two are now eminent scientists; the third switched from Chemistry after graduation and has reached the top of his chosen profession. So here's to all those who teach or have taught. You change lives, and you will always be remembered.

LPC810 If you're interested in Electronics you will know that ARM-based chips are found at the heart of many fantastic consumer products: mobile phones, tablets, and of course the Raspberry Pi. ARM technology has been hackable for a while. I first met the mbed a couple of years back. It's useful, and fun, but what I want now is an ARM board that I've designed and built myself. Sadly, my ageing eyes and fingers make SMD soldering a challenge. What I need is an ARM processor in DIP format. And here it is! nxp actually make two DIP ARM chips. This one is the LP810 - a 32-bit processor in an amazing DIP8 package. Adafruit have a super tutorial on how to breadboard and program it - just what I want. That promises to be fun, and opens up all sorts of possibilities: imagine stripboard-based projects with a 50MHz 32-bit processor at their heart. The LCP801 should keep me busy for a while, but I've just ordered its big brother, the LPC1114. That offers 50 MHz ...

I've been working hard on the notes for the Shrimping It workshop I'll be running as a diversion at BCS SPA next week. A Shrimp The diversion is running on Monday 30th at 19:15.  That's slightly later than the time I originally posted. The notes should be useful to anyone who wants a detailed guide to building a Shrimp, and I've decided to open source them under a CC Share-Alike Non-Commercial License. The notes are currently a work in progress, but I'll be editing and completing them on-line over the next few days. I will publish them as an eBook on LeanPub with a minimum price of £0.00. This means that you can 'buy' the book for free and get future updates as they become available. The eBook is not quite ready for publishing yet, but there's a sample available up on GitHub . When you click on the link you'll be offered a chance to view the whole file; that will download a copy of the pdf for you to view at your leisure. I'll remo...

I mentioned a few days ago that I'd started to use Fritzing for PCB layout as well as breadboarding, and promised to share my experience of PCB Fabrication Companies for Fritzed designs. Here we go. I needed three iterations for the lobstar board, and I got each one made by a different manufacturer. Three versions of the lobstar FritzingFAB I sent the first iteration (on the left in the picture) to FritzingFAB , the service organised by Fritzing. As you might hope, it's really easy to do from the Fritzing user interface. I was a little over-confident and decided to order two copies of the board. Fritzing charge a set-up fee, and they also charge for postage, so the cost per board is significantly lower if you order multiple boards. Two copies of the board cost £18.90 (including VAT and Postage), and my boards arrived 11 days after I placed the order. The board has black silkscreen on white solder-mask and the solder pads have a lead-free HASL finish. Ragworm I s...

Last week I mentioned the Shrimp-based workshop that I'll be running at SPA on 30 June: 'build your own Arduino clone'. The workshop will run at the end of a full day so I'm keen to keep it as easy as possible. A random act of kindness has helped to make it even simpler than I'd expected. A delightful surprise When Cefn Hoile sent me the batch of CP2102 adapters I'd ordered for the workshop I discovered a delightful surprise: a full Shrimping It kit, complete with diagram and components. Cefn has been helping people to build their own Shrimps for a while, and he's got things down to a fine art. He's worked out a breadboard layout that reduces the number of jump wires you need. A change I'd planned (using a 5v LED with a built-in resistor) adds a little to the cost but simplifies the breadboard layout even more. Shrimplified for the SPA workshop I've ended up with this, which is about as simple as I can get using a crystal oscillator...

based on the Shrimp I'm running a workshop at BCS SPA 2014  called 'Make your own Arduino ™  clone'. The clone you get to build is based on the Shrimp - a low-cost and very successful breadboard or stripboard based version of the popular Arduino microcontroller board. The BCS SPA conference is an annual event that's been running for 18 years, bringing together experts and practitioners to share the latest thinking in software development. SPA conferences are unique; the sessions are interactive and hands-on, so no-one suffers death by Po***Point. This year SPA is running from 29 June to 2 July at the BCS offices in central London. One part of the SAP tradition is that the formal programme is supplemented by diversions; the workshop is the diversion for Monday 30th June. It will run from 18:00 to 19:00 (at which point I'm off to the pub). Even if you're new to electronics and the world of Physical Computing, this hands-on workshop will send yo...

The night I think I nearly died A couple of nights ago I felt chilly and put on a sweater. A little later I felt something painfully hot against my chest. I realised that it was my mobile, which was in my shirt pocket under the sweater. I hastily took the phone out and turned it off. It was almost too hot to touch. A few minutes later it was back to normal and it has worked fine ever since. Here's what I think  must have happened. My body heat and the heat from the phone were retained by the insulation of the sweater, and the phone's LiPo battery must have started thermal run-away. Remember those exploding laptops a couple of years ago? I reacted in time, but overheating LiPo batteries are bad news. My phone was conveniently located next to my heart. A very close run thing! Lesson Learned Keep your phone ventilated and do nothing to overheat it. Jam tomorrow If you were expecting a post about PCB FAB companies, I'm afraid that has taken longer than I thought...

Yesterday I got involved in a couple of discussions on Twitter on two related topics: choosing software for PCB design, and choosing PCB Fab companies to make short runs of prototype boards. I'll write a little about the PCB Fabs in another post. At the risk of having to don flame-proof safety gear, I'll share some of my experience from the last couple of years, and my current preferences. Quick2Wire Analogue Board Disclaimer Please don't expect an exhaustive survey. I don't normally work on Windows, and I don't have a Mac, so this is written from the perspective of a Linux user. That's why I have not tried DesignSPark PCB. Nor have I looked much at KiCad, simply because my first attempts some while ago were discouraging. Eagle and Fritzing The two products that I have used are Eagle and Fritzing. Eagle is very well established as a design tool for amateur and professional users. It's very capable, and has very extensive libraries. Since CAD...

By Kristian Bjornard from Baltimore, USA (Lock up on a metal Gutenberg-style press)  [CC-BY-SA-2.0], via Wikimedia Commons From the Printing Press... Over five centuries ago Gutenberg introduced moveable type to Europe, and the whole world changed forever. His printing press heralded the era of mass communication, leading eventually to mass literacy, cheap textbooks, newspapers, scientific journals and other media that produced massive and rapid social change. It helped to fuel Renaissance and Reformation, and its effects persist in the digital age. ...to the Raspberry Pi Today the Pi is changing worldwide education in much the same way. Two brilliant, simple, Pi-compatible ideas stand out for me: KA Lite and Kiwix . KA Lite brings the content of Khan Academy to environments without high-speed reliable internet access. In many locations around the world, internet access is limited, expensive or non-existent but smartphones are cheap and widely used. Run a ...

I spent last Thursday at Kids Adore Ditch , and I can't remember when I last had so much fun. The event was organised (in less than two weeks!) by James @Monkchips Governor. It took place in the Shoreditch Village Hall - a great venue, with plenty of space, power and wifi bandwidth. Just as well! Over thirty kids turned up, and I counted at least nine different activities to keep them occupied. High spots included a banana-controlled quadcopter, a robotic arm, digital drawing, Minecraft on the Pi, Scratch, and a couple of coding-based games. Many of the activities were run by IBMers, and local company Kuato Studios also contributed. Special kudos to Neil Ford, who ran the minecraft station, and Linda Sandvik who introduced Scratch coding. More details, and some pictures, on Dan Light's blog . I took along some robots - two Pololu 3Pi models (seen below) and my very own C3pi (in the foreground). Courtesy Marco Abis  @ capotribu   The 3Pi robots ...