What could be more fun? Oh, yea, you have  a long list. Okay, let me press on.

There are a few things which microcontroller fans might like about ST Micro’s new product:

1MByte Flash, and 192KBytes of RAM. I remember reading the Unix edition six source, and IIRC, it would run in 128KBytes RAM, and that was a multi-user , multi-process operating system, with a proper hierarchical file system (none of the A: nonsense). That amount of memory is quite luxurious for Arduino users. It is 32 Arduino UNO’s worth of Flash, and 96 Arduino UNO’s worth of RAM.

Floating Point Unit. Modern PC’s have hardware floating point. For some problems, it is much easier to write a solution using floating point numbers than whole numbers (integers). For example manipulating angles, or digital audio signals. A floating point number is one with a decimal point, like 3.1415926, or that is tiny, like 10^-126, a number which makes a yoctosecind seem like an eternity (seriously, the age of the universe, measured in yoctoseconds is only 4.3×10^41 yoctoseconds), or big, like 10^127 (that’s the digit 1, with 127 zero’s after it).

The nifty thing about floating point numbers is they keep track of the position of the floating point for you. Most microcontrollers don’t have floating point hardware, so programs have to do all the bookkeeping and arithmetic in software. You don’t have to write the code because the compiler will do that for you. This can be a bit weird because it looks just the same as integer arithmetic, but the program is bigger and slower.

ARM publish a few benchmarks which suggest Cortex-M processor with hardware floating pont might be 10x faster than the same processor doing floating point arithmetic in software.

That is quite a big deal, if you want to use something like trigonometry, where calculating sine or cosine are themselves a bunch of floating point calculations. We really might see that 10x speed change.

Why do I care? Well, I am very interested in things which might inspire and motivate children and adults to learn programming. Sound and music are an area that lots of people love. Simple notes can be described by sine curves. So it would be very handy to write simple programs which generates values on a sine curve, and pumps them out through a Digital to Analogue Converter (DAC), through an analogue audio chain, so that we can hear it.

Something like:

const float frequency = 440.000; // A above middle C
const int sample_freq = 44100; // CD audio sample frequency, 44.1KHz
const int samples = sample_freq/frequency; // number of samples/cycle
while (true) {
    for (int i=0; i<=samples; i++) { 
        dacWrite( sine(i * 2.0*PI / samples) ); 
        delayMicroseconds(1000000/sample_freq); 
    }
}

That is too rough to work well (the delay might not be accurate enough, and it ignores the time used to do the calculation and loop) but I hope it is enough to illustrate the idea. Fast floating point should make maths and music easier to program.

STM32F4DISCOVERY is the low-cost development kit that STM are offering. Farnell are taking pre-orders, it is £9.26+VAT! They are about $16 in the USA, but I didn’t see any distributors with the stock-arrival date.

That is an amazing price if you were to compare to something that has to be sold at a profit, like an Arduino UNO. Of course ST Micro don’t have to make a profit on this, they might regard it as the cost of a marketing campaign. I much prefer this approach to a fancy, glossy, high visibility marketing campaign. I don’t want to look at fancy ads. I want the product at a price which I can’t ignore. Thank you STM.

I’ll try to pick up again, and mention some of the other nifty stuff, but if your interested, please check out the datasheets and reference manual.

It also talks about creating yoctosecond gamma-ray pulses.

Folks may know, light travels at 300,000Km/second, or 3×10^8 m/second (10^8 is supposed to be 10 raised to the power 8 or 100000000)
A hydrogen atom is about 1.1 Ångstrom in diameter, 1.1×10^-10m (10 raised to the power -10, or 0.0000000001)
So, light travels the diameter of a hydrogen atom in 3.6×10^-19 seconds,  0.36 attoseconds (10^-18), or 360 zeptseconds (10^-21 seconds)

A yoctosecond is 10^-24, so light would travel 1/360,000 of a hydrogen atom diameter. Hydrogen atoms are small. Even thinking about the time it takes light to streak cross one is amazing, but a yoctosecond is a tiny time.

If I were going to drive for the next 4 and a bit days, 100 hours, to go between, say, London and San Francisco (on an imaginary road:-), at about 54 miles per hour, that is the first second of the journey.

I find that utterly mind boggling.

The talk about BBC.Codelab by Alan O’Donohoe, a secondary school head of ICT. I was able to speak to him on Saturday, and he said that he was part of a pilot project by the BBC which would be rolled out April 2012. The project will give every school child their own computer, support and resources. The support was targeted at children and not teachers.

I was flabbergasted. I have had a few conversations with people at the BBC, and have heard no mention of this, so I had to go along. This could be amazing. My hopes and dreams to give every child the opportunity to learn to program, and more importantly, that computers are a vehicle for creation and not just consumption, might be only a few months away! Life changing.

The room was quite small, and was packed, with lots of folks standing. He had the session chair video his presentation, so Tony was focused on Mr O’Donohoe and not the room.  The talk began with a brief history of him becoming excited by programming the BBC micro, but then how he’d spent the last 18 years teaching ICT. He talked of his ‘Damscus moment’ a year ago when he realised he was teaching how to use Microsoft Office, but not how to program applications.  He talked of how he felt he had let the children down. There was warm support in the room.

As people heard the proposed roll-out of millions of computers across UK schools, and tried to ask questions, discussion got more ‘energetic’. He suppressed all attempts to interrupt him. He took no questions, and treated people like they were naughty children . Folks thought it was somewhat amusing, but the another explanation only became clear later. He was ensuring his video was only of him, and no objections or questions. Once he had finished, he stopped the video recording.

Not surprisingly, people active in the Open Source community, and concerned about Computer Science and programming education in schools were very agitated, and wanted to know why the BBC had not engaged with them. Another person thought this announcement must be connected to the RaspeberryPi charity.

One person said that he had been at the September 16th BBC Manchester Barcamp. He said that he thought it wasn’t as presented. At this point Alan got a bit uncomfortable, and said that people may be very unhappy with him. Eventually he said it was all a hoax. People burst from the room, mostly frustrated at the total waste of an opportunity to do something positive. As we left,  Mr O’Donohoe asked people not to reveal it was a hoax.

I was flabbergasted for a second time. Alan said that he had presented the idea at the Manchester Barcamp. He said it had caused a lot of excitement, and claimed several people had congratulated him on the amount of excitement it had created.

I felt so strongly, that I put myself down for two lightning talks. I was hoping to ensure everyone who had overheard earlier fragments of conversations, but not been in the talk, knew it was a hoax. O’Donohoe had put himself down already for a lightning talk, so I assumed he would be revealing the hoax, and apologising for wasting everyone time. I was wrong. He talked about how useful twitter is.

I was stunned. I had expected him to explain his reasons for his hoax. Or apologise for the the hoax. Maybe apologise for consuming everyone’s time when we could just as easily have spent the same time, enthusiasm, talent and experience on making progress on children’s education. So I went ahead and tried to explain the O’Donoue’s BBC.Codelab was a hoax, and that there are several bad things that it might cause, as well as the wasted opportunity.

IMHO, it was genuinely risky to suggest that the BBC had ‘solved’ such a big education problem as teaching all children to program, with such an enormous roll-out of equipment, with so little engagement with one of the communities who might help.

I feel deeply sad that the talk was a hoax, and children will not all have their own computer next April. I am sad that all of our time was wasted, when it could so easily have been applied constructively. It was pretty clear that a lot of people in the Python community care a lot about education. It seems sad that this talk stirred up negative emotions rather than directing a positive outcome, given the level of interest already in the Python community. There is time for the wider Open Source community to get involved and help education move forward, but we need to be constructive rather than fantasists.

I am still pondering what motivated Alan, and whether or not he would have said it were a hoax without the challenge from the Barcamp attendee? Maybe no one can know.

http://arduino.cc/blog/2011/09/17/arduino-launches-new-products-in-maker-faire/

The “Arduino Leonardo” is simpler, and should be significantly cheaper than an Arduino because it uses an ATmega with on-board USB. This looks pretty much like a “Teensy” from PJRC but with an Arduino UNO board layout.

The “Arduino Due” uses an ARM Cortex-M3 processor, in this case an Atmel SAM3U4. Unfortunately, that chip is quite big, 100-pin or 144 pin, so cost might be an issue. Atmel might give them good discounts,. We will see. It is forecast to be available by end of year.

From the brief spec, I think it is a 144-pin part, the SAM3U4E. That gives lots of Input and Output (I/O) pins. I am very interested in small robots, so that is quite big for a micromouse.

Compared to the ARM Cortex-M3 I am working with already, the ST Micro STM32F103, the exciting new feature of the Atmel SAM3U is high-speed USB (480Mbits) on-board, and it runs at 96MHz.

In other STM32F comparisons, I think the STM32F is slightly better for my areas of interest, though I would have to use a 144-pin STM32F part to get the full external memory interface.

The SAM3U does not have any Digital to Analogue Converters (DACs), whereas the comparable STM32F103xC (high density) part has two. Comparable STM32F has three 12-bit Analogue to Digital Converters (ADCs) which is slightly better than the SAM3U4 two ADCs. There is an interface to good quality audio chips called I2S. SAM3U4 has one I2S interface, while STM32F103 has two. What does this all mean? If you want to build audio projects, the STM32F might be a better starting point.

It is extremy useful for robots to keep track of their own position by measuring wheel movement (odometery). The technique often used is the same as older ‘ball’ mice. Internally a ball mouse has two orthogonal small wheels which rotate when the ball rotates. The two orthogonal wheels have slots. Light shines though the slots, and each time the light beam is broken, movement is detected. By using two beams and two sensors on each wheel, it can tell which direction the ball is moving. This technology is a quadrature encoder.

Quadrature decoders are very useful to track and time the quadrature encoder. STM32F103 timers can each implement a quadrature decoder, and hence some parts can provide upto 6. I had thought I’d misunderstood the SAM3U4 datasheet, but Atmel have confirmed it only has one quadrature decoder. This is not an issue, unless you want to build robots which ‘know’ where they are.

I am very pleased that the Arduino team are working on ARM Cortex-M3. I think this will encourage a lot more people to use the 32-bit ARM platform. Coretx-M3 is capable of so much more than the 8-bit ATmega, that I expect a significant flurry of new projects next year when the Arduino Due is fully developed.

Meanwhile, I’ll keep working on STM32F, and watch out for results from the Arduino Due .

I lead two sessions where I spoke about the background of Arduino, and the importance of Open Source. Then everyone got their “hands dirty” wiring up simple electronics and programming the Arduino. The attendees were D&T teachers, D&T support centre consultants and technicians.

Traditionally, schools use some version of the PIC microcontroller, but, I am told, schools teachers are being asked about Arduino. This is an intriguing development. It is good that there are folks out there encouraging education to get involved with Arduino, which has a very different image to the PIC-based systems.

As well as traditional breadboard-based electronics, we also tried Paul Gardiners ‘Explorer” modules. I have designed a simple Arduino shield which plugs into the Arduino, and enabled people to very quickly construct electronic systems using Paul’s electronics modules. Paul has developed almost 50 modules, so there is a lot of scope, and they can be combined to explore and develop an idea quite quickly.

The effect is transformative. Using Paul’s modules, the activity uses most of the time for programming and debugging the code. When I use breadboard-based electronics, I usually find a lot of the time is spent debugging the elctronics.

The sessions were welcomed, and worked quite well, though they were too short to cover as much ground as I would like. We have a solution to this though, because I am doing another workshop for teachers at the weekend.

I have always been the type of person who likes to understand how things work. I like to read manuals. Even as a child I read the manuals for my brother’s HiFi so I knew how to do make it do pretty much anything possible. I like looking at low-level code, and digesting Microcontroller manufacturers manuals. I like reading technical stuff, especially over a balmy Holiday Weekend.

I sometimes work with folks with technical backgrounds in software not hardware or low-level embedded systems who want to do more. They have all the knowledge and skills to program the hardware, but the hardware manuals are too hard a place to start. It is surprisingly rare to find good introductory material for low-level technology which is both approachable and also detailed enough to enable non-specialists to go further.

I was pleased to stumble into a set of resources for embedded systems at “EE Herald”
http://www.eeherald.com/section/design-guide/index.html

It includes a section of “On line Courses” on common embedded communication interface ‘standards’. The tutorials include USB, I2C, SPI, CAN, LIN, Serial, and RS232. Those standards are used to communicate with individual chips such as accelerometer sensors, other microcontrollers, host PCs, SD memory, Wii controllers, controllers in manufacturing plant, and parts of cars. There are also section on ‘IEEE 802′ local area and wide area networking standards.

The sections I’ve skimmed seem to have good coverage and a decent level of details. The tutorials include some helpful diagrams, which helps folks like me a lot, and are written at useful level of technical detail without going down to the manufacturer specific hardware.

For example USB is covered in
http://www.eeherald.com/section/design-guide/esmod14.html

I have only skimmed it, but it reads as good coverage of USB 2.0 from history to physical hardware, electrical levels, signalling, end-points and protocol including packet formats. It isn’t as detailed as the USB specifications, but I don’t think many people would want to start their! I like to get a good overview of the way a system works before digging into the detail, and I like to have a broad technical understanding to stitch detail into.

The USB article at EE Herald isn’t perfect. It includes a very brief overview of USB On-The-Go (OTG), but not enough to feel I could properly understand the STM32F USB OTG hardware. USB On-The-Go includes the more complex host-side of USB, so it would be impressive if they had got that too. I feel that is a minor and common weakness.

It is a readable alternative to
USB in a NutShell at http://beyondlogic.org/usbnutshell/
USB made Simple at http://www.usbmadesimple.co.uk/

These won’t replace the manufacturers manuals (e.g. ST Micros STM32F RM0008), but they cover generic technical detail, and look pretty good. I’m hoping they may be enough overview for anyone who wants to read low-level code or hardware specific manuals like STM32F RM0008 or the Atmel ATmega 48/88/168/328 manual.

I briefly looked at some other articles in the EE Herald design guides, and they are not all good quality. I felt disappointed by the ‘MEMS based motion sensing design’. It had almost no useful detail; I thought it was weak even as marketing ‘puff’. I wouldn’t feel ready to tackle a manufacturers MEMS datasheet after reading that.

EE Herald have some links to other sites, including this useful looking article on 1-Wire Interfaces from Maxim which has a lovely list of 1-Wire Application Note links at the end. Ideal Holiday Weekend reading

I learned a huge amount from them. This is the result.

OROne STM32F103 Robot Controller - without 0.1" headers

It is based around an ST Micro STM32F103CB Cortex-M3 microcontroller. This version has 128K Flash, 20K RAM, USB, CAN, 3xUSART (serial),15xPWM, 16xADC, 2xI2C, 2xSPI, and JTAG in a 64-pin package, all ticking along at 72MHz.

The board adds dual DC-motor drive, seven LEDs, two buttons, two servo sockets, as well as sockets for six analogue input, two quadrature encoders, and headers for JTAG and Serial. The two 30-pin 0.1″ headers (missing from the photo) gives access to all of the microcontroller signals and power on a veroboard friendly grid. The microcontroller can be powered over USB, or via an external power supply or batteries. The board also has independent on-board voltage regulation for the servo’s and motor drive chip.

Like an Arduino, it is ‘self-programming’ over USB once the bootloader has been installed. I installed the bootloader over the microcontrollers on-board serial interface using an ordinary FTDI USB to serial cable. So it doesn’t need JTAG or an in-circuit programmer, ever.

It is based on the Maple from LeafLabs. LeafLabs have built an IDE using the same Processing-derived IDE as Arduino. It sits on top of GNU GCC. They have also implemented most of the Arduino base-libraries, so Arduino programs may move across to Maple with minimal or sometimes no changes. To top it all, they have developed a bootloader which enables the STM32F103 to program itself over USB. The whole software environment, libraries and bootloader are Open Source, and runs on Windows, Linux and Mac OS X.

Maple is a magnificent piece of work. My board ‘came up’ in a couple of hours (after we found and fixed a couple of my PCB errors).

Chris did much of the construction; he has a very steady hand. We used the ‘Mini-oven SMD technique’. Paul Gardiner of Finham Park school in Coventry did a workshop a while ago, and this is the biggest board I’ve made using it.

I’ll describe some of our experiences, and where-to-next over my follow-up blogs.

The video is presented by Jeffrey Gough of  Warranty Void If Removed. He is working to make DIY Printed Circuit Boards (PCB’s) much quicker and easier. He is aiming to reduce the PCB manufacturing process to two steps: print, etch. His ink-jet-based printing mechanism will directly print wax onto the PCB material to resist chemical etching.

The video talks about many different methods of making DIY PCB’s (maybe the first 30 minutes). Most ‘normal’ methods use printed circuit board material which is fibreglass boards covered in copper. A circuit is formed by removing the unwanted copper using a chemical etching process. The mass-production methods use photographic technology to apply an image differentiating the circuit and unwanted copper  using a technology which protects the required copper from the etching chemicals (it is actually many steps, as the industrial process is more complex than the one used by DIY PCB techniques). DIY PCB makers often use a photographic process which leaves a protective chemical ‘film’ over the required copper. This requires several steps before getting to a stage where the copper clad fibreglass can be etched into a PCB.

The approach proposed on the video is very different. Jeffrey Gough prints wax straight onto the board, and the wax resists the etching process. So there is no need to make intermediate ‘tools’ to create the photographic image, and no need for intermediate ‘manufacturing’ processes.

His approach is to modifying a low-cost (€40) Epson ink jet printer so that it can print wax straight onto blank PCB material. He did a lot of reverse engineering to build a piece of electronics which could take over driving Epson’s print head. It appears to be able to print tracks as fine as 0.1mm, which is better than most commercial PCB manufacturing process (that I can afford

The print head is heavily modified to keep the wax liquid while being printed. When liquid wax is ‘fired’ from the print head nozzle, in the same way as ink is ejected, it solidifies (freezes) on contact with the PCB copper, forming a wax covering which protects the copper from the etching chemicals.

The development is far from complete, but it shows real promise. It might revolutionise PCB production for professional design engineers, and not just DIY makers. If it were robust enough, every school and colleague that does any electronics would use it. For me, making one-off, prototype PCB’s is the slowest, and often most costly part of exploring an idea. This would remove that obstacle. By using Surface Mount Technology and Devices (SMT/SMD), I could make a PCB in well under an hour using this process. I’d use surface mount technology to minimise the drudgery of drilling hoes in the PCB. I’d solder the whole board in my trusty mini-oven using solder paste.

One slightly frustrating part is Epson could probably bring this to a production prototype stage in a few months with a few people.  If anyone at Epson is reading this, there may be a real market for such a printer, and Epson are one of the few printer manufacturers who use piezoelectric print heads, so the market may have very little competition while the products are developed, sold and improved.

It struck me how striped down some kinds of Making can be; talent, voices and collaboration. It’s like ‘glitching’ every instrument and studio technique to a single ‘sound technology’; only the essence remains. The ultimate ‘Unplugged’.

I very much like ‘Kiss from a Rose’, they can sing.

My digging around got started because I heard a superb rendition of Gangsta’s Paradise.

This is a pretty cool piece of A Capella, with video, but I think ‘All A Capella’ played a different version tonight, which sounded better to my ears. It was by University of Pennsylvania Off the Beat.

Many of the performances ‘All A Capella’ feature are college groups. It is great to hear talent, enthusiasm, discipline, ingenuity and ‘cojones’, whatever the sex, are flourishing.

We don’t need computers, Arduinos, blinky-LEDs, reprap, soldering irons, glue-guns, or even duct-tape to make amazing things.

Let’s Make a Difference!

I ran three workshops introducing Arduino and basic electronics, and two intermediate, follow on Arduino workshops. To keep costs down, we had 12 complete kits, and asked folks to work in pairs. There were a mix of skills and expertise, and the folks supported each other so well that two of use were able to provide success to 24 people. I should add a special thanks to Dave Chalis*. He was incredibly helpful. Without him, day one one have been less smooth, and much less fun.

Folks gave lots of useful feedback and encouragement. So I hope to do even better in the future.

*Dave I apologise if I have misspelled this, please someone correct me.