Friday, 31 January 2014

A year later ...

366 days ago, I replaced about a dozen full-size servers with Raspberry Pies. They've now been running for 366 days non-stop. No crashes, no problems. I hadn't expected such a good reliability for a £21 computer!

Bike porn

I was up till late last night, looking at bike porn. Electric bikes that go faster than a car, that can go up a flight of stairs. But specifically, at mid-motor bikes.

With most electric bikes, the motor is in either the front or back hub (or both), and drives the wheel directly. With a mid motor drive, it's mounted near the cranks. You replace the crankshaft and cranks with a shaft that has two sprockets. One of the sprockets is driven by the motor, the other one drives the back wheel via the usual chain and rear gears.

The big, big advantage of that, is that the motor is driving the back wheel via the gears. So to go up steep hills, you can change gear down; to go fast on level smooth ground, you change up to top gear.

Another advantage is that the motor, plus fixings, is a few kilograms lighter than the hub wheels.

So, for example, this

The cost is £300, I already have the batteries, doesn't it look nice? For off road use only, though.

Wednesday, 29 January 2014

Mud, water and mud. And water.

North to Nassington for a day that was notable for the amount of water, and mud.

The weather forecast was for some showers, and that's what I got. Wen I set off on the first circuit, "Another wood and back" it was raining lightly. Apart from the fact that rain gets me wet, there's a couple of other problems. One is my glasses; when they're speckled with rain, I don't see as well as I'd like. The other is the PDA - it isn't weather proof, and if it gets wet enough, it could stop working. So I packed a spare PDF, just in case.

I got my first bootful early on. It wasn't actually a bootfull, but a bit more than a trickle made it's way inside my boot when I tried to cross a ditch that was deeper than I'd hoped.

A lot of the route was on tarmac, but a lot wasn't. And that's where the mud came in. It isn't that I mind getting muddy. But the bike doesn't fly so well on soggy muddy ground, and I had to do quite a lot of walking the bike.

The high point came when I did the second circuit, "Elton Furze and back". One of the first few caches was on the other side of a ditch that was flooded. I was hoping that it wasn't very deep. I was sadly disappointed, and I went in up to my knees. And that meant I spent the rest of the day walking on water. With cold, wet feet.

And on mud - some of the bridleways were so soggy as to be unbikable, so more walking was needed.

I had hoped to end the day with a wicked puzzle cache that would involve wading hip-deep at one point, and I'd come prepared for that. But when I got to the starting point, it was clear that I'd be wading chin-deep (or worse), and so I sadly left that one for a time when the floodwaters recede.

I set a record for battery usage (because fighting through soft mud takes a lot of energy). I completely used  the first four batteries, and partly used the fifth. I have six altogether. I think this is telling me that when summer comes, and I stay out longer, I'll need a couple more.

66 caches done, one DNF

Tuesday, 28 January 2014

Overvolting bike.3 - part 2

First, I repaired an old speedometer whose wire had snapped, and installed that.

Then I tried to take the handlebars off the bike (which I'll have to do to put it in the car). You remember I replaced the disc brake on the front wheel with a caliper, because the motored wheel couldn't take a disc ... well, I used a cable that was a bit too short. The brake worked fine, but the brake cable wasn't long enough to let me unmount the handlebars. Grrrr. So I replace the cable with a longer one (and had to do it again because when I cut the outer to the right length, I stupidly cut the inner too, and thereby wasted an inner cable. Annoying, but those inner cables are only a few pence. And now the bike was ready to test. By the way, bike.3 is 7 pounds lighter than bike.1, the bike I'm currently using. That's a nice thought, for when I'm lifting the bike over obstacles.
First I measured the speed with the existing batteries (8 cells), which, being freshly charged, were 33.6 volts. With the front wheel held above the ground, that came to 21 mph. That, of course is the speed with no load; with a heavy rider on board (me) that would be a lot less. But useful for comparison. That gives me a reference point.

Then I plugged in more volts; 12 cells, which comes to 50.4 volts. I was expecting my voltmeter to give up, it's only supposed to go from 0 to 30 volts. It only cost about £1, so I wasn't that bothered if it broke. But it didn't, it showed the voltage correctly. That's nice.

Then I ran the bike, again with no load. This time I got 32 mph - again, that will be a lot less with a load. But it does indicate that giving the bike 50% more battery, means that I have 50% more oomph. What I'm interested in isn't speed, it's torque.

When I'm caching, I'm biking from cache to cache, typically 2-300 meters; 500 meters is a long gap. I don't need speed, Even at 12 mph, that's about a minute. It takes me longer than a minute to dismount, prop the bike up, and remount; finding the cache can be anything from a few seconds to 20 minutes. So speed isn't important, because even if I biked at 24 mph, I'd only be saving half a minute per cache. And anyway, when I'm going over rough ground such as many bridleways are, I probably do a lot less than 12 mph.

What is more important to me, is torque at low speed. Torque is what pulls me up hills, and over rough ground, and gets me through squishy ground. So this looks like rather good news; I can add 50% to my torque without (I think) any cost.

I have to try a longer run, to see if the motor or controller starts to get hot, And I'll try it out on a local hill. And I also want to try it with 16 cells (67 volts). To do that, I have to make up a new wiring harness that puts four of my Hobbyking batteries in series, and I'm waiting for the various connectors I've ordered for doing that.

Tomorrow, ladysolly is out till late, so I will be also. I'm going North to Nassington, there's a couple of circuits there that are calling me.

New controller

After much thought and comparison, I've ordered a sensorless infineon controller with 6 mosfets, which means it should be able to give my motor up to 25 amps. A mosfet is a metal–oxide–semiconductor field-effect transistor. They're very good for high-power applications, such as electric bikes. And ... the controller is programmable! So I can program in things like top speed, high and low voltage cutoffs and current draw. Actually, I ordered the sensored controller by mistake, but I emailed them and said I actually wanted the sensorless, which is the same price (I suspect it's the same device with fewer wires).

I've also ordered the cable for programming it, a neat thumb throttle, another torque arm (see previous blog for what that is) and a nice box for testing ebike motors and controllers. From China (is anything made anywhere else now) so it'll take a few weeks. I'm planning to install it in bike.3.

Total cost, including shipping, is less than a tankful of petrol for the car. Just to put it into perspective.

Monday, 27 January 2014

Overvolting bike.3

Bike.1 is looking good, so it's now stowed in the car. And I got bike.3 out to have a bit of a look at it.

It has a 24 volt motor. That means 24 volts nominal, but when a 24 volt battery is freshly charged, it's actually 29.4 volts (seven cells in series). I've been running 8 cells in series, nominally 29.6 volts, 33.6 volts when freshly charged, and that seems fine.

I've been doing a lot of reading, and I think I could give it 50% more volts. 12 cells in series, 50.4 volts when freshly charged. It might not work, the controller might refuse it, but I don't think that the motor will explode - at worst, it might get hot, and I can keep an eye on it and stop if it gets too hot to touch. The rule of thumb in such matters, is that until it's too hot to touch, you're fine. I've also bought an infra-red gun thermometer, so I can check temperature without touching it.

It's easy for me to try this; I just have to wire up a harness that puts three of the 4-cell batteries in series. And I'm trying this on bike.3, because it has my least favourite motor, it's a motor without Hall-effect sensors. Meaning, if I blow up that motor, I'll be sad but not devastated.

The first thing I noticed, was that the rear brake doesn't work. Fortunately, I discovered this before I got on the bike, while I was still checking it out. On the other hand, the front brake does work - isn't it a good idea that bikes have two brakes!

The rear brake is a disk brake, and the problem was that the cable wasn't moving in the cable outer sleeve. I tried oiling it, but that didn't help much, and eventually I replaced the cable inner, and now the rear brake works OK.

Before I can make up the wiring harness, I need connectors. I'm not sure whether to use Deans (T-connectors)

or the more recent replacement for them,  XT60s.

I want connectors that can, fairly easily, be plugged and unplugged without A) any possibility of plugging them the wrong way round, B) without any possibility of accidentally causing a short circuit and C) they come apart when I want them to and D) they don't come apart when I don't want them to.

I'll experiment with both kinds before I decide what to use. Right now, I'm using kettle plugs and sockets, and they do meet all four of the criteria above, but A) they're a bit big and bulky, and B) they're only rated for 13 amps, and I thought they'd be carrying about that, but actually my wattmeter tells me that 30 amps is going through them, and they are feeling just slightly warm. The Deans and XT60s are rated for 60 amps.

I'll need thicker wiring, too. The wiring I'm using now is also rated for 13 amps, so using it at 30 amps is a bit cheeky. I have reels of thicker wire; 2.5 sq mm, and 4 sq mm. Different authorities give different carrying capacities for wires, because it depends on how well heat can leave the wire, but they go (for 4mm) from 30 amps to 100 amps. HobbyKing (who I feel are fairly expert in this) say that you can put 70 amps through 14AWG (which is 2.08 sq mm), and 2.5 sq mm should be able to carry somewhat more than that.

So I checked it in my Fowlers Electrical Engineer's Pocket Book, 1943 (price 4/- and a very good four-bob's-worth it was too, and if you want one, I see they're available on Ebay and Amazon). I inherited mine from my father, and page 503 is showing 50 amps for the 4mm, and who can you trust if not Fowlers? And the 2.5 mm would therefore be good for 35 amps, which means that I can safely use the 2.5 cable, because I'm actually expecting to run 15-20 amps if I use 12 cells for 50 volts, and it should also be good for trying 16 cells (67 volts)  which I'm thinking might go to 30 amps.

So I've ordered connectors, and they're on the slow boat from China right now.

Internet persistence

Anything that you put on the internet becomes almost impossible to remove. It gets copied and recopied, and you never know who is eventually going to stumble upon it.

So don't put anything on the internet that you don't want your children to see in twenty years time.

Friday, 24 January 2014

An eye on the charger

I've found that sometimes, in the middle of charging up my bike batteries, the charger cuts out. I think this is caused by too much load on the power supplies that I'm driving them with. It's easily dealt with, I just power-cycle the power supplies and all is fine.

But if I don't know it's happened, I can't do that. And the charging is done in the garage, all the way downstairs from my office.

Technology to the rescue. I've installed a webcam, pointing at the chargers, running off a computer that was already there, using "streamer", which is installed in Red Hat Linux by "yum install xawtv", not an obvious phrase. It means that I have a picture like this:

which refreshes as often as I want it to. I can see the two chargers, and although I can't read the displays, I can see whether they are on or off, which is all I want.

And I just wanted to share with you how dogs and cats teach their young

I had to clean my screen after I watched this.

Bike maintenance

I replaced the back brake pads, the old ones were looking too worn. I also took the PDA mounting bracket off because it was loose and flopping about. I made a handlebar-thickener out of a floppy disk drive cable and replaced the holder, it's nice and tight now. 

I read about a problem that I haven't had. If you're using an front motor (I am) and you have aluminium front forks, then the torque from the motor can crack the place where the wheel is held in the fork. If that happens, you get a spectaculat face-plant, because you suddenly have no front wheel. If that happens at speed on tarmac, ouch. For me, it's more likely to happen at low speed on bumpy grass, but even so, ouch.

I've got steel front forks, and steel is much less likely to have that problem. Aluminium breaks, steel deforms (bends). Even so, I decided to install a torque arm, which I got on Ebay for £12.99. Call it insurance.

So when I tested the bike ... it didn't work. Aaarghhh! So I left it for a while, replaced a spacing ring that I'd left out next to the throttle, because I didn't think it was needed ... and it worked fine!

I've been reading in more depth about electric bikes. Apparently, the over-volting that I did (24 volts up to 29.6) is very minor. It might be possible to go to a lot more. And that means more oomph to get up some of the steep hills that I find myself facing. I'll read some more about this. I have the Forza that I couldn't sell for £200, which means it's worth less than £200, so a good candidate for experimentation.

I've offered to do a talk at the Kent Mega event about "How to build an electric bike for £250". They like the idea. If I do it, I'll illustrate the talk with a bike, to show how easily it all goes together, it's like making your own computer, you just buy the bits and plug them together.

Wednesday, 22 January 2014

Sawtry sojourn

Up north to Sawtry today, with bike.2. The theme of the day was mud. Mud, mud and more mud. I took much of it home with me.

I started off on Little Gidding and back; halfway round, I diverted to pick up three "Twin Turbine Trail" caches, two multis and a puzzle. And a few others in the vicinity. Then back to the circuit, and I completed it and was back at the car at 2pm. So I had lunch, took out the two empty batteries and put in two full ones, and set off on the second circuit, Sawtry and back.

Little Gidding and back was pretty muddy, but I managed to avoid most of it by careful routing. I'd rather do three times the distance on the bike if I can avoid a the sort of mud that clogs the bike up.

Sawtry and back was,I think, muddier, but again I used my mud-avoidance strategies. But I had to cross the middle of some very muddy fields, and that's fatal. I went round the edges instead, so at least I was able to push the bike, but the mudfullness was terrific.

I finished off with a cache just outside the Adult shop, and then on the way home I had another go, (successful this time) at the cache in an underpass under the A1.

61 caches altogether, and no DNFs! A grand day out.

Monday, 20 January 2014

Dog food, part 2

I started with this 12-year-old laptop that daughter.2 had used at university. Two of the keytops are missing, so I plugged in a USB keyboard and I hate trackpads so I plugged in a mouse. Then I installed Fedora Linux version 9 (which I used because it needs less memory than more recent versions). But when I tried to update it (yum upgrade) it didn't upgrade Firefox, which meant I couldn't install Adblock. I thought of messing around with it to try to get it to work, then I decided not to.

So I installed Fedora Linux version 20 (which is the latest version). The laptop only has 512 mb of memory, which I thought wouldn't be enough. But it was, and the operating system installed fine. I then did "yum upgrade" to get everything current, installed Noscript (that stops web sites running their javascript programs on my computer unless I specifically allow it) and Adblock Plus (that block adverts, which is a good idea because a malware drive-by install is, I think, more likely to happen from an advert (which can be put up by any unethical scroat) than from the web site I'm looking at.

This means that now I have an up-to-date, fairly secure computer, which I'll only use for buying stuff (which mostly means Ebay, Amazon and Deal Extreme) and not for general surfing the web or email, so it's even less likely to get malwared than my usual Linux box.

It's quite surprising that a 12 year old laptop can still be useful! Thanks, daughter.2

Web comics

There's four web comics that I check each day.


xkcd (Monday, Wednesday and Friday)

Questionable content (weekdays)

Jesus and Mo

Saturday, 18 January 2014

Eating my own dog food

This is an expression which means "use your own product", or "take your own advice".

I used to do general-purpose stuff (web browsing, email etc) with a Windows 98 computer. Then it got hit - I'd just visited The Register (a tech news web site) and one of the advertisements there did a drive-by install on my system. That means, it just did it, it didn't ask me to click on anything. Just the act of visiting the site, installed the malware.

I spent half an hour trying to get rid of it; it kept coming back, Then I saw sense, and decided to just do a clean install. So I zapped the hard drive (wrote zeroes all over it), and I was just about to re-install Windows 98, when I thought, hang on. I'll go Linux.

Ever since then (and that's several years ago), it've been using Linux on my general purposes workstation; for web browsing, email, logging in to other computers, and so on.

I get hundreds of emails enclosing malware each week. Hundreds! I just delete them unread, unopened. Not a problem. But it makes you think. And when Ian (Kewfriend) reported what happened to him (see previous blog), I advised people to get a cheap, second-hand laptop and use that for anything financial, such as buying things online, using Ebay, Paypal and any bank stuff. And don't use it for installing software, general-purpose web surfing, email, or anything else apart from the stuff that you hope to keep secure. Money stuff.

I've always felt that just using Linux is sufficient protection for me. But I thought that several years ago, and the situation has clearly gotten a lot worse.

So I dug out a laptop that had a couple of missing keytops, plugged a keyboard and mouse (I don't like trackpads) into it, and I'm installing Linux on it.  It's not a great laptop; I inherited it from daughter.2 because of A) the missing keycaps and B) a loose power connector. And it's not fast. But it's good enough for using as my secure computer.

Because I'm planning to eat my own dog food.

To Braintree with Ladysolly

We stopped off at London Colney to get our sandwich lunch and Starbucks, then on to Braintree. After lunch in the car, we set off to do "Cludo who dunit?". At each cache we found a few cards showing people, places or murder weapons, and I carefully noted down the information on them. The mud along the way was awful, we were slipping and slinding and squidging and squelching, and we brought quite a lot of it back home with us. We found all the caches, and then we sat in the car for out coffee and bun, and thought about how to get coords out of these.

In Cluedo, you deduce the murderer, place and weapon by seeing which cards are missing; this was similar, except that we had to get two lots of murderer, place and weapon(one for Northings and one for Eastings). In addition, we had to decide which order the numbers should be in to give the coordinates. I'd been thinking about this as we walked along, and it was only in the last 100 yards before getting back to the car that I came up with two possible theories, which both turned out to amount to the same ordering.

The task was made a little more difficult because in one cache, the log was missing and the cards were dirty, which meant that something had happened to that cache. And I think that one of the cards had gone astray there. So we wound up with two possibilities for the bonus cache. Fortunately, they were close together, and when I got there, one could be eliminated easily. And sure enough, there was the bonus cache, big and lovely. I left a 250 gb cache, excellent series.

18 caches done today. Thanks to infinison for setting the series.

When your computer security is breached.

Ian Murray uses Barclays . Here's what he reports, via Facebook (repeated here with his permission).


Nine months ago I visited the IrfanView site and downloaded its free (and very good) picture editor. Yesterday Malwarebytes informed that the download had been infected with a stupendously pernicious backdoor programme. Though this has since been removed, what was uploaded remains unknown and my machine muct be assumed to be compromised.

As my friends know I have been subject to some nasty bank frauds.

However, as ther evidence I am about to present shows, the banks have enabled the fraudsters. ( To be fair ... they have been excellent in dealing with the consequences - but their systems INVITE fraud. ) If basic bio data about you is known: address, dob, phone etc then you are shafted.

1) On using a Barclaycard for the first time these days (if you are not already registered online ) you receive this email:

Thank you for registering to Barclaycard Secure services. This free service provides added safety when you shop online. Activation Details: Activation date: 25/12/13
Merchant at which activation took place: JLP Website Amount of purchase: 168.00 Login name: IANMURRAY22 The service is now active for your Barclaycard card ending with: XXXX-XXXX-XXXX-0000

If your email is compromised in any way, Barcalys has just told ANYONE how to use and raid your account.

2) Read the uploaded picture (mastercard) about PIN and cards. Provided basic bio data is validated on a new card Barclays will inform ANYONE over the phone (and online) your PIN.

3) The other uploaded Debit Card had NEVER BEEN USED. It was still attached to its original letter in the original envelope in a locked filing cabinet. Its associated PIN had nevere been scratch revealed. Fraudsters activated and used the debit card. How?? Inside job??

4) The PayPal fraud - possibly the worst security loophole. In the UK (in fact all over Europe due to money laundering legislation) it is a very slow and difficult process to open a new bank account.

To open a PayPal account is EASY - a few clicks. Your credit card and bank details can then be uploaded and linked to the PayPal account. Provided the two small credits to your uploaded details are verified ( here guesswork and multiple tries makes it easy ), then the link to your bank account/credit card is set up.

If the account was set up in your name ( with correct bio-details etc ), then effectively the fraudsters have used a dozen clicks to OWN your bank account. In my case they used a nonUK phone number - big mistake - they were over confident.

If you think your bank details are confidential - WRONG. they are written on every cheque and on your debit card. They are PUBLIC.


What was Barclays reactions to all this. To be fair they have been excellent in correcting the situation. But they have no intention of making their systems less of an open door. Unofficially I was told that it is cheaper to pay off the fraud than to implement new systems or lose customers because of stricter security. This is an agreement across ALL UK banks. In Europe particularly France and Germany two stage text message authentication is required. The UK banks have rejected this as bureaucratic. The UK banks have also rejected the French system (much much more secure) of pick and click character entry from the screen in favour of simple typing of login details: which ANY KEY LOGGER will detect. Their view (again) is that the European system will lose them customers and is too bureaucratic. The fact that it is far far more secure is considered irrelevant.

I apologise for this long posting - if you have read to the bottom, then you are fully up to date and informed.

Bank computer security isn't good enough

The banks aren't going to up their game. It's partly because they don't know how (bank security has been dreadful for a long time) and partly because it wouldn't be profitable for them to do so. If you want to avoid the sort of hassle that Kewfriend has had, you have to take charge of your own security. And that isn't easy.

As soon as malware is installed on your computer, it can log all your keystrokes and other activity, and send it to a server outside the UK. If someone has your details, they can open a Paypal account (or one of several similar services), using your bank account or credit card, and buy things or transfer money to another account.

You know all those "Do you want a job" spams? That's recruiting money mules. The money mule receives the goods or money. If goods, resells it on Ebay. Then they send 80% of the cash via Western Union (or similar) to the criminal, and at that point, the money is safely laundered and cannot be recovered. Someone will be out of pocket.

So you have to stop malware getting installed on your computer. How? 1) Don't click on any attechments in email, even from people you know, because their account might have been taken over. 2) Don't visit any web sites; even kosher ones show adverts and one of those adverts (coming from another server, not run by the kosher site) can deliver malware. 3) Don't install any software, even from kosher sites, see Kewfriend's experience. But is this practical advice? No.

 So here's what I tell people. Get another computer. £100 will buy you a used laptop on Ebay. It doesn't matter what's on it, because you're going to install Linux from a CD or DVD, thus wiping out all previous stuff on it. Then you use that laptop for anything financial or purchasing, and for nothing else. The combination of A) Linux and B) not using it for most purposes gives you good (although it's never perfect) security.

 It doesn't matter if you don't know Linux. Installing it is easy, the only question you need to answer is, what language do you speak. The rest is automatic. All you're going to be using is the graphical user interface (which is very similar to what you're already used to) and the browser (which is the same as you're used to).

 I'd also suggest using Firefox as your browser, and using Noscript and Adblock Plus. Noscript stops any Javascript from running; Javascript gives remote computers the capability of running programs on your computer, so you would only allow that for sites that you really trust, such as Amazon, Paypal, your bank. Adblock Plus block adverts, which is nice just for that, but even better for security as it stops the attacks via ad servers.

Friday, 17 January 2014

Wages and beer

George Osborne suggests an increase in the minumum wage to £7 per hour. Sounds good! Let's look at this more closely.

This means an 11% increase in wages. But the worker pays more taxes, so it's an 8% increase in what goes into the pay packet. And a 47% increase in what the government gets in income tax. So, nice for the worker, even nicer for the government, and with the deficit, sorely needed. Good all round then!

Hang on.  That money comes from somewhere.  Ah ... the employer pays an extra 12%

Now let's look at another suggestion - a minimum price for alcohol. The idea is that by enforcing a minimum price, this pushes up the price of alcohol, which reduces consumption.
That makes some sense - it's usually the case that if the price of something goes up, people buy less of it. If I were a heavy beer drinker and they put the cost of beer up by 15%, I'd probably buy less beer. More malt, yeast and sugar, of course, because brewing your own beer (which I used to do) is easy, fun, safe, legal, and costs 25 pence per pint.

So, if a pushing up the price of alcohol is expected to reduce alcohol sales, what happens if the government pushes up the price of employing someone?

Just as for beer, there's substitutues. The substitute for buying beer, is malt, yeast and sugar. The substitutes for employing someone, are:

a) Employ someone where labour is cheaper
b) Use a machine
c) Stop doing the labour-intensive thing, and do something that needs less labour

All of these end up with less employment. How much less? I don't know, and I don't think anyone else does. Do our politicians care? I doubt it. Increasing the minimum wage looks good, sounds good and does your election prospects good, and after you've done it, you can point to loads of people who are 8% better off.

And the people who become unemployed as a result? They don't have a voice.

Thursday, 16 January 2014

Two trips to Oundle

As planned, a trip to Oundle. And it was a good plan; I parked and started off, just after what I thought would be an on-foot segment, got bike.2 ready with all six Hobbyking battery-pairs (that's 30 amp-hours, one kilowatt-hour) because I was expecting a long trip with no chance of getting back to the car halfway. So I started at cache 17 and went north. I was mostly on tarmac until I got to Oundle, where I did a couple that have appeared since I last cleaned out Oundle, then South, again on tarmac. I stopped off to do one in Barnwell Country Park that I'd failed on last time I was there; it turned out that I had failed because the cache had gone, but this time I found the replacement.

Then onwards on more tarmac until I got to Barnwell. At that point, I was on bridleway, but that led across a field, and I got mud-clogged, which meant *very* slow progress. But after a while, I was back on grass, and then a long segment on tarmac again. Eventually I got to the point where I'd expected to get off and walk, so I chained the bike to a handy bench, and walked the last mile. I got back to the car at about 4:30, just as it was getting dark, and drove to where I'd chained up the bike. I had lunch, drank my coffee. By that time it was 5:30, full dark, and my back was aching as it always does after a hard day, so I decided to go home. Three and a bit batteries used, which was about what I expected.

I got home at about 7pm, en route collecting a curry for my dinner, and as I got out of the car and started to unload it, I noticed that something was missing.

The bike.

I'd forgotten to put the bike back in the car, and because I was driving in the dark, I wouldn't have been able to see it in the rear mirror. So I thought about this. The bike was still leaning on the bench, but not locked. It would probably still be there tomorrow, or Friday, but it could get stolen; bikes are very easy to steal if unlocked. I did have the batteries, so it was just the bike plus the motor and controller, a total value of about £250, and a trip tonight to collect it would cost £50 in petrol, but if you also take into account the cost of my time and depreciation on the car, then that probably exceeds the value of the bike and it would probably be most rational to leave the bike there and hope to collect it next time I went out caching.

But decisions like these aren't taken on entirely rational grounds. This was bike.2, my faithful steed, which has borne me over rough and smooth, and I couldn't find it in my heart to risk abandoning her to some thief who would possibly maltreat her.

So, a second trip to Oundle. I made the 200 mile round trip, over three hours, and she was still standing by the bench, waiting patiently for me and was very happy to be folded up and loaded into her space in the car.

69 caches found, 1 DNF.

Tuesday, 14 January 2014

Better than ping

Ping is how I usually check that things are working. But if you're having connectivity problems, try using this:


That does a repeated traceroute to Google, and the statistics cumulate. So, not only do you see what percentage are getting lost, you also see at what point in the chain they got lost.

Oundle outing

Bike.1 tests OK, so I made a waterproof covering for the wiring out of an old oilcan and duct tape.

I'm planning to go out to Oundle tomorrow. I've been there several times before, There's an izaakwilson series Barnwell and Back, with 65 caches, plus a few extras. I'm taking bike.1, and I hope it works!

With a long series like this, I like to do it as two parts, but I can only do that if there's some way to duck out halfway and get back to the car. That won't be possible, because the river Ouse is in the way, and there's no suitable bridge where I'd need it to be. So I'll set off fully loaded with batteries and other supplies.

Bike failure

Bike.1 performed magnificently yesterday; I went through 3 and a bit batteries, which means about 20 miles.

Today, I gave it a wash down (it was very muddy from the outing), and when I tested it again - nothing. Dead. I suspect that water has got into the works, either the motor or the electronics. I'll leave it to dry out for a while, meanwhile I'll use bike.2

 ... later ...

Bike.1 is working fine. I didn't do anything to cause that, so I think it just dried out!

I'll try to think of a way to really waterproof the controller and wiring. I don't think I can do anything about the hub motor.

Atheism advantages

There's a lot of advantages in being an atheist.

1) There's thousands of religions, if you choose the wrong one, you go to hell. Or something.
2) You don't waste lots of time praying to the invisible sky thing.
3) You don't waste lots of money building buildings for the invisible sky thing.
4) You don't get to pay for people to pray for you to the invisible sky thing, only to discover that instead of praying, they're preying on your children.

But there's an advantage I hadn't thought of. You get to live in the UK. This fellow has successfully got asylum in the UK, on the grounds that he's an atheist. The reason is, some religions say that you have to be killed if you decide to change from their religion. And this is the case in Afghanistan (for example), where the law prescribles the death penalty for failing to believe in their official religion.

Monday, 13 January 2014

Jessica's Jaunt

Today, I went up North. Unfortunately, there was a 25 minute traffic jam going down the road from Amersham to the M25. Is this permanent? It's happened twice now.

On the way up, I saw two very major traffic stoppages on the southbound carriageway; on one of them, I saw the recovery vehicle loading up a car, and the police were diverting traffic off the A1. I was glad I was going North!

When I got to my starting point, I parked, and got the bike out. But when I tried to use it, it went backwards!


That explains why it was going backwards yesterday, leading to me changing the leads around. Some fool had put the wheel on back to front. I considered riding round today with a back-to-front wheel, but soon decided that was crazy.

So I opened up the duck tape that sealed the wiring, reconnected the connectors so that they were yellow-to-yellow etc, and tried the bike. No reponse. I made sure that the Hall leads were fully home, still no response. I was getting to the point where I was wondering whether I should abandon the bike and walk round, when I noticed that the throttle lead had become disconnected. So I connected it back up, and hurrah! So I re-wrapped the cables in duck tape, and got ready for the Jaunt; I thought I'd need two batteries, so I took four. By that time, it was 11:30, and I'd hoped to start this more than an hour ago.

I did it in two stages. First I went down the "Jessica Shortcut", then east and north to complete a circuit of 41 caches, arriving back at the car at about 3pm.

On cache number 21, I had some fun with a muggle.

I got as far as the tree where the cache was, when a lady muggle in the house opposite and 30 yards away, hailed me. "That's a bit unusual," she said. I looked at the tree, and said "No, I think it's a perfectly ordinary tree". "No," she said, "I mean you, what are you doing?"

So I went into my "Hard of hearing and a bit stupid" routine. I think I actually am a bit hard of hearing, I have trouble hearing people when other folk seem to hear just fine. And I have an unlimited supply of stupid.


She repeated herself. "I can't hear you, could you speak up?" She was about 30 yards away. She tried again. "Sorry," I said, I still can't hear you, hang on, I'll come over to where you are."

"Never mind," she said, and pedalled away.

By the time I finished the first circuit, I'd gone through a lake so deep that I had water in my boots, which is never nice. I had a quick lunch and coffee in the car, took the two used batteries off the bike and put two fresh batteries on; again, I thought I'd only need two, but it's better to have too many than too few.

The second circuit was about 30 caches, but of course it got dark while I was going round. Fortunately, nearly all the track was good. Apart from one place where I filled my boots again,

I got back to the car at 6:30, finished my flask of coffee, took off my wet boots and socks, and set off for home. 71 caches done, 1 DNF

Sunday, 12 January 2014

Resistance is useless

I measured my resistance today. The lowest I could get it, was across one hand, with wet fingers, and that was 50 kilo-ohms. Dry, or across both hands, more like 100.

Why is this important?

I'm thinking of a future bike I might build, using a 48 volt battery. The question is, can I electrocute myself with that, or even get a nasty shock?

The strength of shock depends on the current; 5 milliamps DC is considered to be so small you won't feel it. And if I'm 50 k-ohms, then the current from 50 volts would be 1 milliamp.

If this were AC at 240 volts (like the UK mains), then I'd conduct 5 milliamps, and that's a pretty bad (but probably not fatal) shock. But that's AC, and with AC a shock feels a lot worse than with DC My bike is DC, and Wikipedia says I'd barely feel 5ma DC, and my worst case, as per my measurement, is 1ma. So I don't really want the bike to fall into a canal, but even if it did, I wouldn't perish from electric shock.

Although the cold would probably do for me.

weight report 77

15 stone 7 pounds. Hurrah!

Saturday, 11 January 2014

Bike maintenance

After taking bike.1 out for a long, wet ride, I made a list of things I needed to do to it.

The saddle wasn't high enough - fixed.
The pannier bag wouldn't close properly - I have a strap I'll use.
The gear shifter wasn't returning, it was fouling the throttle - moved it.
The thottle wasn't returning to zero when I released it; I've oiled it and it's fine now,
The bracket that I'd made out of plastic to hold the rear light broke; I've made one out of steel now.
The red rear lamp fell apart; the red plastic fell off the body. Sellotape fixed it.
Even with tape over the blue battery condition lights, I was still being dazzled by them at night - another layer of tape added.
And even the voltmeter LEDs look very bright at night; I've now got a flap that I can fold down to cover them.
The voltmeter was showing about half of the correct voltage. It's working now, I don't know what was wrong.
The horn button wasn't in a place I could easily press; sometimes, when you want to beep the horn, there isn't time to search for it. Button moved.
The time was wrong on the bike computer - fixed.


Maybe the ammo can I'm using for a battery holder is too wide. I've replaced it with a narrower bag.
The clock/thermometer arrived, so I've installed it. So I'll know just how cold it is while I'm out, and I can see the time.

Then, in recharging the batteries, I found that battery 5 (of the 5/6 pair) has a wonky connection. I've taped up the connection, but I'm not sure if it'll be good enough. If it's still a problem, I can always replace battery 5, those batteries are only about £15.

And before I put the bike back in the car, I tested it. Just as well! It didn't work. After some messing around, I found that if I started the wheel off going backwards, then it would run ... backwards. That points the finger at the controller, or maybe a loose wire. So I undid the tape that keeps the leads from the controller out of the wet, and I think I found a disconnected wire (although it's possible I disconnected it when removing the tape). So I reconnected the wire, and the wheel went fine without needing to be started off ... only backwards. I really can't imagine what could have caused this to happen, but I know how to deal with it. Instead of connecting the power leads yellow-yellow, green-green, blue-blue, I scrambled them, so that the same colours didn't connect. That had the effect of making the motor go the other way. Result!

I also decided that I could simplify my wiring harness, by incorporating the watt-meter and fuse in with the special lead that connects a pair of batteries to the bike. So, less wiring, and therefore less to go wrong. I'm also going to make up a spare lead, so I ordered a couple more fuses.

I've also separated out the bike repair kit, so that it can go into a miniature pair of saddlebags that can go on the front frame. Or the same bag can go in a rear pannier. In this kit, I have:

Puncture repair kit: patches, glue and tyre levers
Multitool for bikes
Spanners for front and rear wheel
Spare inner tube (not one of my excellent pucture-proof ones, this is a thin light one, just to get me home).
Quite a good lock (not good enough for leaving the bike in a town center, but good enough for leaving it in the middle of the countryside while I walk a few hundred yards across a place I don't want to take a bike).
Rear light. For a front light, I prefer to use a head torch (which also has a rear light). But two rear lights are better than one!

So now, I think, bike.1 is ready for the next outing, although I'm going to give it a further test tomorrow.

Wednesday, 8 January 2014

Denton delight

North to Denton today, to take bike.1 on it's first big ride since I put in the new wheel and other kit. It went well, although I made a list of ten small changes that I want to make on the bike.

The only problem was, of course, the wetness. Weeks of heavy rain have left water water everywhere, especially on bridleways. Some of them were so soggy, I had to walk the bike.

First I went down Sewstern lane, which was just about ridable. Then along a dismantled railway. I always like those, usually the surface is good and there's no gradient.

But it wasn't a good surface. Look:

I saw a lot like this today!

Eventually, I got to the Grantham Canal, and biked along the towpath; that was an excellent surface, and I made good speed. When I got to the Grantham end of the canal, I left it and went back via the A607. a good fast road, and I was able to pick up a couple more caches on the way back to the car.

I got back to the car just as dusk was falling, about 4pm, so I had lunch, and debated whether to do some more caching. I decided to continue, so I went up the Viking Way (very bad surface, I was mostly walking the bike), which got me back to the canal, where I went east to Woolsthorpe Wharf. By then, it was past six, it was raining, and I was feeling rather tired, so I biked back to the car and went home.

54 caches done, and a few DNFs.

Sunday, 5 January 2014

Sorting out the Sweex

You know how it goes - in the middle of sorting out one problem, you find that you have to sort out another, and while you're doing that, you find  ....

I was getting problems with a server called "data4". That's a Raspberry Pi, with a 400 gb hard drive attached. I use it for doing backups of sensitive data that has to be encrypted - mostly, that means credit card data. And so data4 has encryption on it, using the Linux encrypted file system.

I looked at the SMART data for the drive, and it had 93 replaced sectors. That means that the drive is limping, and needs to be replaced. It's probably not the fault of the Raspberry Pi.

But, instead of replacing the drive, I decided to bring up another computer to do the job, or rather to add another function to an existing computer. So I chose a computer that was already being used for backups, and had 100 gb on a spare drive. I set up an encrypted file system on that drive (that's very easy to do, look here) and started copying the data to it.
And while I was doing it, the limping drive conked out completely. Never mind, all I need to do, is use the new drive to do the same backup.

I also use that drive for monitoring the Data Shed. I have an IP camera pointing at the sensitive areas, and it records video, in case I have some problem that requires me to see which of my staff was there when the problem happened - that's a PCI DSS requirement. Of course, there's only one member of staff - me. But still, it's a requirement. The box must be ticked!

On the new backup computer, everything was working ... except the camera. I soon realised that, although the camera was working, I couldn't access it from the new computer, and it was obvious why. The camera is on, data4 was on but the new backup computer is

Some history.

A long, long, long time ago, I was allocated to as my very own range of IP addresses, so I could have up to 254 computers. A long, long time ago, I realised that this wouldn't be enough, so I made all my computers have addresses that start with 10, and I started off with to 255, in honour of the addresses that I was allocated. That means that, internally, I address a computer as, for example,, but if I want to allow external access, then I have to set up an equation that tells my firewall to translate to and vice versa. And if I want the outside world not to have access to, then I simply do not set up that translation. It's called NAT, "Network address translation". And it's magic; not only do I get all that security, I can also use any IP address that starts with 10, so instead of just 254 computers, I can have 16 million. Which should be enough. By the way, the use of NAT turned out to be very helpful when I had to change my IP address range from 195.149.17.x to something completely different, because it was more convenient for my ISP, my inconvenience not being a factor, of course. Because I was using NAT, the change was pretty painless. And that's nice, it means that if I want to change my ISP, which will means changing all my IP addresses again, it'll be pretty painless again.

So I was happily using all sorts of addresses that started with 10, but on my IP camera ... oops. I set it up a long time ago, and I gave it the netmask Which means, "you only need to reply to computers that start with 10.149.17". So you can see what happened; my new backup computer was, and the IP camera was ignoring it.

OK, simple problem, easily fixed. Hah! That's where it started to get difficult.

I logged in to the IP camera to change the netmask to (which means "reply to all computers that start with 10.", and the IP camera said "Please Use Internet Explorer 5.0 or higher". But I'm using Firefox on a Linux computer. It wouldn't accept Opera or Chrome, either. So I switched to the Windows box, running Windows 7, used for GSAK and Memory Map, that don't have a Linux version. The IP Camera let me access its configuration, but now the Windows box was saying "That thing you're asking me to run is unsigned and therefore untrusted" and it dumped me out.

After trying a few times, I decided that it just wasn't going to let me do this, so I went back to Firefox under Linux, and looked for a way to pretend to be Internet Explorer.

 When your browser acesses a web page, it announces what it is, via a thing callled "User Agent". And I found something that would let me pretend to be Internet Explorer version 6, 7, 8 or various other things. I happily installed it, and tried the IP camera again. "Please Use Internet Explorer 5.0 or higher". It wasn't fooled. I tried various things, but couldn't persuade the IP Camera to believe that I was using Internet Explorer.

At that point, I started to think that maybe the only way to resolve this, would be to  change the IP address of the backup computer to be in the range 10.149.17.something. But I hadn't quite got to the end of my tether. Google is my friend.

I asked Google, "How do I make Windows 7 let me run an unsigned app, if I'm willing to take the risk?" Because I don't think there's a risk, this app is coming from my IP camera. And there is a way. If you need this, Google is your friend too.

So that let me access the IP camera configuration, I changed the netmask to, and now it all works.

Friday, 3 January 2014

Junk mail

Just before Christmas, a large, glossy catalogue was sent to my company address, which is actually the solicitors office. They, naturally, forwarded it to me. I noted that there was a postage cost of £4.60.

So I wrote to Alto, the people who sent the catalogue:

You sent a catalogue to me, which was neither requested nor was it wanted.
You do not have my address; you would have used the Companies House database (or possibly you were sold a list which was compiled from that, there are many unscrupulous list vendors selling such lists as "opted in" at exhorbitant prices).

The catalogue was sent to my registered company address, which is my lawyer's office. They
forwarded it to me, not knowing that it was unwanted junk mail.

This resulted in a cost of £4.60.

I would like you to refund that cost.

Let me know how you would like to pay this.

They have replied, offering to refund the £4.60 and to remove me from their mailing list. I have accepted their offer.

Weight report 76

15 stone, 10 pounds.

iPlayer recommendation

I found this by accident. Old jews telling jokes.

Thursday, 2 January 2014

Daisy support

A few days ago, on Monday, I got an email from Daisy to tell me that my leased-line connection to the internet was misbehaving. "Flapping", which means, I think, intermittent connection. On the same day, and before I'd seen that email, I contacted them to report a fault - I was seeing intermittent connection to the internet.

The replied by telling me that they couldn't see any packet loss, and asked for "a trace-route to highlight the packet loss". So I sent them the results of a ping test, showing 11% packet loss. Later ping tests showed 30%, and eventually 50% packet loss. That's a severely bad line.

They came back with a graph, and the statement that "the packet loss you are experiencing is due to maximum bandwidth utilization". The graph showed max utilisation for a bit over one hour, and that was the hour when I do my across-the-internet backup. The rest of the graph showed less than 10% utilisation, yet I was still getting packet loss.

Daisy's suggestion was that I upgrade my connection. Or, to put it another way, spend twice as much money with them for a connection that wasn't working properly and still wouldn't be working after the upgrade.

So I explained this to them. They came back with the suggestion "check that you have re-seated the Serial cable and that it is firmly connected". I did that, it was. Also, rebooting the router had no useful result.

By this time, it was three days after I reported the fault (a fault that their own monitoring had also alerted them to). So I escalated the problem - I called Sales and asked them to administer a nudge to their technical people. Because what's the point of paying big bucks for a leased line (which has the main advantage of high reliability) when it's performing a lot worse than a £15 broadband?

That got a result. I got a call from their NOC (Network Operations Center) to tell me that they've discovered a fault on the line, and they were telling Vodafone. Who have now purchased my leased-line from Cable and Wireless, who bought it from ... you don't want the full history, but I've changed suppliers so many times now (without me actually making the change) that I sometimes forget who I need to call to report problems. And they were also going to send out an engineer to replace my venerable 1700 router with a spiffy new 1800, just in case that was part of the problem. I said I'd be in all day.

At 6pm, I got a call from the engineer; he was having trouble finding the site. I have no idea why they don't issue their roving staff with satnavs; that would have found me, using the post code. He was phoning from a nearby golf club, and I gave him directions. And then I told him "Daisy mentioned to me that they were cancelling the engineer visit", because Vodafone say they've found the fault and a BT engineer has fixed it.

Loose wire, I expect. Or a squirrel nibbled the cable.

So the engineer called Daisy, who confirmed that they've cancelled the visit.

And it looks like my line is back to 100%, hurrah!

So now I'm asking Daisy, how come it took them three days to do something that actually took, once they got serious about it, a couple of hours?

And then the courier arrived, delivering the router that their engineer will not now be installing.