The SECO Model 250 Transistor and Tunnel Diode Tester

This is a quite rare device I picked up on Ebay some years ago, for testing transistors and diodes, including tunnel diodes.

 

The instructions are on a label pasted to the inside of the cover, and are unfortunately in a sorry state.

Here’s a better image from a recent (2012) Ebay auction for the same type of tester:

Instructions (found elsewhere)

Arduino based hexapod robot

This is a project I’m working on: a six-footed robot controlled by an Arduino processor.

The Arduino is a Duemilanove with a BMA180 accelerometer shield attached (this is used for dead-reckoning of the robot’s movement). There are six “legs” using twelve servos (HobbyKing HK15138 rated at 3.8kg @ 5V) arranged radially in pairs around a central platform. The upper servo on each leg is mounted horizontally and controls the leg twist. The lower servo is mounted vertically and has a short dowel foot that can rotate in the vertical plane.

The servos are powered from a separate 5Volt high current supply (from an old Sun desktop workstation) that can deliver several amps. The servos are attached to a servo board made from a small piece of Veroboard which shares a common ground with the Arduino.

The Arduino code uses the servos.h library to position the servos. Here is the code:


// Control code for the hexapod
// JJB 2012

#include

Servo legServo[6];
Servo footServo[6];
// angles for each foot servo so that the foot is vertical
int zeroFoot[6] = {60,90,100,95,95,95};
// angles for each leg servo so the servo arm is at right angles to the platform
int zeroLeg[6] = {120,100,95,90,110,100};
int maxangle = 45;
int NLEGS = 6;

void setup() {
Serial.begin(9600);
Serial.println("Attaching servos:");
for(int i=0;i<NLEGS;i++) {
int ileg = 2*i+2;
int ifoot = ileg+1;
legServo[i].attach(ileg);
footServo[i].attach(ifoot);
Serial.print("Leg ");
Serial.print(i);
Serial.print(" Leg servo pin ");
Serial.print(ileg);
Serial.print(" Foot servo pin ");
Serial.println(ifoot);
}
centreServos();
}

void centreServos() {
Serial.println("Centre servos");
for(int i=0;i<NLEGS;i++) {
legServo[i].write(zeroLeg[i]);
//delay(2000);
footServo[i].write(zeroFoot[i]);
//delay(2000);
}
}

void crouch() {
Serial.println("Crouch");
for(int i=0;i<NLEGS;i++) {
footServo[i].write(zeroFoot[i]-maxangle);
}
}

void stand() {
Serial.println("Stand");
for(int i=0;i<NLEGS;i++) {
footServo[i].write(zeroFoot[i]);
}
}

void liftFoot(int i) {
footServo[i].write(zeroFoot[i]-maxangle);
}

void rotateLeft() {
Serial.println("Rotate Left");
for(int i=0;i<NLEGS;i++) {
legServo[i].write(zeroLeg[i]-maxangle);
}
}

void rotateRight() {
Serial.println("Rotate Right");
for(int i=0;i<NLEGS;i++) {
legServo[i].write(zeroLeg[i]+maxangle);
}
}

void liftFootSet0(int dir) {
// dir = +1 forward, -1 backward
footServo[0].write(zeroFoot[0]-(dir*maxangle));
footServo[2].write(zeroFoot[2]+(dir*maxangle));
footServo[4].write(zeroFoot[4]-(dir*maxangle));
}
void liftFootSet1(int dir) {
// dir = +1 forward, -1 backward
footServo[1].write(zeroFoot[1]+(dir*maxangle));
footServo[3].write(zeroFoot[3]+(dir*maxangle));
footServo[5].write(zeroFoot[5]-(dir*maxangle));
}

void lowerFootSet(int i) {
footServo[i].write(zeroFoot[i]);
footServo[i+2].write(zeroFoot[i+2]);
footServo[i+4].write(zeroFoot[i+4]);
}

void swingLegSet(int i) {
legServo[i].write(zeroLeg[i]-maxangle);
legServo[i+2].write(zeroLeg[i+2]-maxangle);
legServo[i+4].write(zeroLeg[i+4]-maxangle);
}

void rotateLeg(int i, int dir) {
legServo[i].write(zeroLeg[i]+(dir*maxangle));
}

void tripodWalk(int nsteps) {
centreServos();
// align first tripod feet
legServo[0].write(zeroLeg[0]-maxangle);
legServo[2].write(zeroLeg[2]);
legServo[4].write(zeroLeg[4]+maxangle);
// align second tripod feet
legServo[1].write(zeroLeg[1]+maxangle);
legServo[3].write(zeroLeg[3]-maxangle);
legServo[5].write(zeroLeg[5]);
delay(1000);

for(int i=0;i 0) {
int inbyte = Serial.read();
switch (inbyte) {
case 't':
tripodWalk(10);
break;
case 'c': // crouch
crouch();
break;
case 'i': // init - centreServos
centreServos();
break;
case 's': // stand
stand();
break;
case 'r': // rotate left
rotateLeft();
break;
case 'R': // rotate right
rotateRight();
break;
default:
break;
}
}
}

Here is a video of the hexapod walking. It’s not very efficient!

Quadcopter: more progress

Now I have the quadcopter fully wired up and operational. I had various wiring problems with it initially, which were solved by enquiries over at the AeroQuad forums. The first was that I had assumed all the motors should be wired up with the same polarity from the ESC, and that the AeroQuad software would take care of setting the direction (a quad needs two clockwise rotating impellers, say at the front and back, and two counter-clockwise, say at the left and right). This was not the case: the simple solution was to swap two of the three motor wires on the left hand and right hand motors. The front and rear motors rotate clockwise, so they need “pusher” props – I am using 8×6 types. The right and left require standard props – I am using 9×4 types. The other wiring problem I had was due to the fact that I’m using an older AeroQuad shield (v1.7) with newer software (v3.0.1) – the shield labels the motor ESC outputs in order as “Front Right Rear Left” but the software has a different order (it can in fact be changed in the configuration) – so I had to swap the ESC leads between the Right and Rear positions on my shield.

Here is a view of the wired up quad’s central pod, made with a RubberMaid food container that was a perfect fit.

Quad central pod, showing wiring and battery attachment.

Notice the on-off slider switch for supplying power from the battery to the Arduino and the motors. Also notice the battery mounted underneath the quad: this is a 2560mAh Turnigy LiPoly flatpack, attached by velcro strips. A view of the underside:

Showing the method of hanging the battery securely under the quad.

The AeroQuad software comes with a “Configurator” that is used to calibrate the sensors and the transmitter. I used this, and in the process found that one of the channels on my transmitter was operating in the wrong direction for the software. This was cured by using a software tool for configuring the HobbyKing 6ch transmitter, which allowed the swap of direction of any channel.

After calibration and fiddling about, I made several attempts to fly the quad, or at least to lift off vertically. It was not a success as the video shows:

After several crashes I found that the pusher props were loose, and the motor mounts had been bent out of line. So I had to fix those problems before continuing …

Quadcopter Progress

I’ve been putting the quadcopter construction (first described in this post) on hold for quite a while, for a couple of reasons. One was that I needed to come up with an idea for the frame, and the other was that I was unsure if I really wanted to build such a dangerous toy! Basically, the thing has four pairs of knives (the propellers) rotating at high speed, on a device that is potentially uncontrollable while airborne – not a reassuring prospect.

Putting the second reason aside for the moment (the quadcopter is only dangerous once the propellers are fitted, and I’m a long way off that point), I started work on the frame.

First I built four small motor platforms for the TowerPro BM2410-08T brushless motors using short lengths cut from of a strip of poplar. To each I attached a small 1/2″ cable clamp into which I inserted one end of each of the four helicopter booms that I’m using for the struts.

Motor mounts

Struts with motor platforms and motors attached.

For the central platform (which will hold the Arduino, RF receiver and battery pack), I cut a 5 1/2″ square of poplar board, drilled a central hole, then attached the four struts using more cable clamps and a central bolt and large washer that presses down on each of four rubber grommets that I placed at the end of each strut.

Method of attaching the four struts/booms to the central platform

After tightening all nuts, the whole frame feels quite solid and stable. It remains to be seen how it will stand up to the high level of vibrations expected!

View of the topside of the completed frame.

Repairing a Sharp Optonica RP-117H

This turntable was bought on Ebay “for repair”. The first problem was that the turntable tray was loose and wouldn’t retract or come out. On removing the covers, a shield over the tray motor and the motor itself it was obvious what the problem was:

Broken tray gear wheel

The gear wheel is split, and has dropped off the motor drive. Here is a close-up of the gear:

Closeup of gear

Because the gear had shrunk a little (probably why it cracked), simply epoxying it together at the crack didn’t work: this made the hole too small and prevented the gear from going back on to the drive shaft. I carefully bored the hole out a tiny amount, then used epoxy to glue the crack and the gear back onto the shaft: I clamped it there for 24 hours.

Next problem was a broken belt for the platter itself: to reveal this involves removing a plate underneath the turntable tray:

Broken belt on motor

The belt had disintegrated, leaving a rubbery mess over the turntable and the motor capstan – removed fairly easily with rubbing alcohol. I ordered a replacement belt, and fitted it by feeding it through from the top of the turntable. It was a bit fiddly, but I’d read somewhere it was a nightmare – I didn’t find that.

Now the turntable tray moved in and out, and the turntable turned. The next problem was that the stylus trays were not moving. These trays move linearly across the deck. There is a clever mechanism with worm gears and a slotted metal disk and opto-transistors that move and detect where each stylus arm is. Here is the mechanism:

Stylus trays mechanism

Just visible at the back of the mechanism is a rubber belt – of course this turned out to be worn and was slipping on the motor and not moving the mechanism. I replaced it with a rubber belt I happened to have in my parts box and fit very nicely. Now the whole mechanism worked. Here is a video of it in operation, showing the switchover to Side B from Side A, which involves the turntable motor reversing direction.

The fitted stylii are by AudioTechnica. The Sharp part number is STY133.

AudioTechnica Stylus

Although the turntable now works, it initially played several LPs without issue, it has now developed a random periodic click/thump, almost as if the record is scratched. This is a little peculiar and hard to understand. To be continued ….

Sharp Optonica RP-117H and Sony CDP-X555ES

Bought a beachfront condo/cottage in Hawaii!

We have bought the cottage unit we’ve been going to on holiday to for the past few years. It came up for sale, and seems like the ideal combination of investment and holiday place. Plus we can rent it out when we’re not there. The whole process of buying it took about 100 days from start to finish, due to an insane amount of repeated paperwork and various delays, but finally the escrow closed today

Anyway, here it is!

Replacing a Celestron PowerSeeker 127EQ Tripod with Something More Sturdy

We have a 4 1/2″ reflector telescope (an Orion StarQuest) which is on a Dobson mount. I got fed up constantly having to reposition the scope while watching e.g. Jupiter, as what I was watching moved out of view. I decided I needed an equatorial mount with a motor drive, and started looking around to see if I could find a mount that would fit the StarQuest scope, but the mounts I found were all very expensive. In the end, I bought a Celestron 127EQ (see Figure 2) which came complete with a German Equatorial mount, for the princely sum of $116 on Amazon.I also ordered a Celestron AstroMaster motor drive (Figure 1), and a Celestron 93625 T adapter and a Fotodex T adapter mounting ring that would allow me to attach my Canon Digital Rebel XSi to either scope (they both have 1.25″ eyepiece tubes).

Figure 1: Celestron motor drive

After assembling the Celestron and fiddling about playing around and understanding the EQ mount, I realised that the supplied tripod was going to drive me nuts: it wobbled and swayed even if I breathed on it. I tried tightening everything up as much as I could, but it still wobbled – it was far too flimsy.

Figure 2: Celestron PowerSeeker 127EQ Newtonian Reflector

So I decided to make something a little more sturdy using bits and pieces I had in the garage. Here are the parts I collected:

• 1 Circular piece of 3/4″ thick plywood, diameter 24″ – base board
• 1 Circular piece of 3?4″ thick plywood, diameter 12″ – scope platform
• 1 5ft length of 4″x4″ wood stock – pillar
• 4 shelving brackets
• 4 3″ steel brackets
• 3 screw thread furniture feet
• 3 nuts to fit the feet
• 4 3″ lengths of 2 1/2″x3/4″ wood stock

Step 1:

Find the centre of the 24″ diameter circular base board: drill a pilot hole through the board there. Place the end of the 4″x4″ pillar upright at the centre of the base board, position the four shelving brackets against the sides of the pillar, mark screw hole positions in the base, and then screw the brackets in place on the base board.

Step 2:

Remove the pillar from the base board, turn the board upside down, then place the base board on the top of the 4″x4″. Drive a long screw through the board, into the 4″x4″, then drill a couple more holes nearby, and drive long screws into those, too.

Step 3:

Turn the board and pillar right way up, carefully supporting the pillar. Now attach the brackets to the pillar with screws, and tighten all screws very tight.

Step 4:

Take the four 3″ steel brackets and attach each to each of the 3″ lengths of wood stock with screws. Then loosely attach each combination to each side of the top of the pillar so that they are centred and level. These will act as spacers so that one can gain access to the nut at the centre of the EQ mount to tighten it.

Step 5:

Using a jigsaw, cut a circular hole in the centre of the scope platform board, of the same diameter as the circular part of the Celestron tripod platform (see Figure 3).

Figure 3: Celestron tripod platform, with new holes drilled at the top of each spoke

Step 6:

Remove the legs from the Celestron tripod, leaving the platform for the EQ mount, and put the threaded rods and nuts that secured the legs to one side. See Figure 3. Drill a hole through the top of each “spoke” of the platform: these will be used to pass the rods through and tighten the platform to the board.

Figure 4: The scope platform showing the spacers and brackets attached to the pillar

Step 7:

Place the scope platform board on top of the spacer/brackets, mark and drill pilot holes through the board into the spacers, and screw tightly in place. Then firmly tighten the brackets against the top of the pillar. See Figure 4.

Place the tripod mount on top of the platform, centre it, and carefully mark the positions of the three spoke holes, using an awl. Before drilling through, make sure that the positions are clear on the underside of the board, and wont foul any of the platform supports.

Step 8:

The platform board should be fairly horizontal at this point, but it’s not critical as there will be adjustable feet added to the base board. These will require captive nuts. Turn the whole mount upside down so that it is resting on the scope platform. Using the centre of the base board, and a protractor mark positions for the three feet at 120 degrees from each other, about 2″ in from the edge of the board. Find three nuts that will fit on the screw feet. Using e.g. a Forstner bit, drill large diameter holes just bigger than the diameter of the nuts, part way through the base board. Find a drill just smaller in diameter than the screw thread on the feet, and drill through the centre of the holes to the other side of the board. Test to make sure that the feet than be screwed in and out of the holes. See Figure 6.

Step 9:

Using a two part epoxy, glue the captive nuts into the holes, taking care that the nuts are centred and that no glue gets into the threads. Leave the epoxy to set. See Figure 5.

Figure 5: Captive nut and adjustable foot

Step 10:

Sand all surfaces, clean with a rag, and then spray paint your choice of colour. (I had a bunch of Rustoleum Navy Blue indoor/outdoor aerosols left over from another project, so I used those.) Leave to dry well.

Figure 6: Mounting the captive nuts and adjustable feet to the base board

Step 11:

Mount the Celestron tripod platform to the scope platform board, using the threaded rods and nuts that came from the tripod. Screw in the three adjustable feet at the bottom of the base board. The platform is now ready to use.

Figure 7: Painting the mount

Here is the finished mount (Figure 8) with the PowerSeeker 127EQ attached. There is a minor problem: the counterbalance for the scope touches against the scope board for low inclinations to the horizon. This will simply require the scope board to be reduced in diameter by taking a circular cut around it – but I haven’t bothered since the viewing area is surrounded by high walls anyway.

Figure 8: The completed home made mount, with Celestron PowerSeeker 127EQ

The Hantek DSO8060 digital oscilloscope

I’ve just received a Hantek DSO8060 digital oscilloscope. This is a dual channel 60MHz scope with a 320×240 display. Samples are 8bit. There are various mathematical functions that can be applied to the signal, notably an FFT. It is also a digital multimeter that measures A,V,R, Diodes and Capacitors. It also has a built in 25MHz arbitrary function generator. There is a USB port for attaching a storage device or connecting to a PC. It comes with a bag, two 10/1x probes, software for Windows, multimeter leads, a coax cable and a good instruction booklet. Here is the scope:

Hantek DSO8060

The screen can be saved to a .bmp file. Here is an example: this is measuring the output of a 416Hz triangle wave signal from a Droid X running my “AudioTool” application:

AudioTool output: signal and FFT on the DSO8060

This also shows the FFT (in blue). There are cursors which can be used to measure features of the channel signals or the mathematical functions, manually or automatically.

Overall, I am extremely impressed so far. The operation is very straightforward and intuitive. i shall be comparing it to my benchtop Tektronix 7844 in the next few days.

A couple of things I haven’t been able to work out: can the FFT data be averaged (the time domain signal certainly can), and how to change the vertical (dB) scale for the FFT.

AdMob

For fun, I thought I would use the AdMob api to include an advert banner in my freeware “Metaloid” application that’s available on Android Market. This is a little banner that sits, rather unobtrusively, above the main screen (see the Figure below).

The Metaloid Field Detector application on Android Market

The Metaloid application has about 20,000 downloads of which 31% are still installed, so about 6,200 active users. The AdMob idea is that you get revenue every time somebody clicks on an advert. Since adding this “feature” (I use the word cautiously), I have earned a grand total of $3.50 for a total of around 80 clicks on 117,000 adverts shown. I shall buy myself a Double Tall Mocha.

Here is the breakdown by day:

WordPress for Android

… seems like a good idea. Let’s see if it works.

First Pizza!

After the adobe oven had dried off for a few days, we removed the sandcastle former by scraping it away from the inside. We lit a fire in the centre of the oven, using scrap wood, newspaper and some barbecue fuel, and let it burn for a few hours.

A couple of days later, we fired it up again, this time using scrap wood and barbecue charcoal bricquets. After a couple of hours or so it had reached a temperature of 550F. The outside walls of the oven steamed as the water evaporated away, and some hairline cracks appeared around the door – this is normal (they closed up when the oven cooled).

After removing the larger pieces of wood, and making enough space to cook a pizza, we cleaned the oven floor’s surface using a damp towel nailed to a long stick. That created a lot of steam! We were careful to remove all the sand and ash from where we wanted to bake – nobody likes a sandy pizza. Then we used some of Trader Joe’s fresh dough to make a simple pizza, and placed it inside – it cooked in a few minutes, and we had to turn it a few times to stop it burning.

(Normally we make our own pizza dough, but for this first experiment we liked the convenience of pre-made.)

The taste was amazing – especially the crust, which had a characteristic aroma and taste particular to pizza from a good Italian restaurant. There must be some chemical change associated with the very high temperature, that you don’t get in a domestic oven.

We cooked a couple more pizzas, and then removed all the charcoal and wood by scraping them out into a metal container partly filled with water. Then we put a small loaf of bread dough in to cook, closed off the door of the oven. It was ready after about 40 minutes. This also turned out to be delicious … with a slight hint of smokiness in the crust.

Charcoal and wood fuel – temperature up to 550F

First pizza cooking – it’s only small

The finished pizza – yum!

First loaf cooked in the Adobe Oven

Making an Adobe Oven

This weekend we set about making an oven for bread and pizzas, using mud. We have a brick barbecue edifice on the patio, and so we used that as a platform.

First we bought and laid 21 red bricks on a 1/2″ layer of sand, making sure to get them even and with small gaps. We could have just used the existing brick oven base, but we wanted something very flat, which it wasn’t. There’s nothing worse than catching your peel on an uneven surface when trying to extract a pizza.

21 bricks laid flat on a bed of sand

Next we marked out on the bricks where the wall of the adobe oven would go: both the inside and the outside edges, using a sharpie. We had bought five 50lbs bags of medium sand, most for the oven wall mix, but some for the oven mould – basically a mound of wet sand like a sandcastle.

The mound needed to be 16″ high, so we first cut a stick to that length and positioned it in a small mound of sand at the centre of the oven bricks.

Then we started to build a sandcastle around the stick, trying to keep the sides of the sandcastle as vertical as possible, and making sure that the sides followed our outline of the inside adobe walls we had marked on the bricks.

Once we had our sandcastle made (in the shape of a dome, reaching the top of the stick), it was time to go digging in the garden for subsoil – the stuff under the topsoil that contains the most clay. We dug about a 3′ deep hole and then extracted a wheelbarrow full of soil.

The clay soil needed to be mixed in one part soil to two parts medium sand. To mix it, we made a ring of four buckets of sand, and put two buckets of the soil in the centre. Then we set about sprinkling it with water and treading it all in to mix it. In fact we found that we had too much sand, and ended up using six buckets of soil to the four buckets of sand.

We checked that the mixing was good when a golf ball sized piece of the mixture, when squeezed tight, and then dropped from shoulder height, didn’t crumble when hitting the ground, but rather just squashed to an oblate spheroid.

At this point we were ready to apply the mud to the sandcastle former. First we placed sheets of damp kitchen paper over the former – this is so that, when we come to remove the sand, after the mud had been applied and set, we could tell when we were at the edge.

16″ measuring stick

Building the sandcastle around the measuring stick

Preparing to mix the clay soil and sand, on a black plastic sheet

The well trodden sand and clay soil mixture

We made an oven door from a piece of old wood. Shaped like an arch, it had to be 12″ at the base and 10″ high. We folded a sheet of paper in half, drew half an arch against the folded edge, cut along the line with scissors, then unfolded the sheet to use as a template on the wood, which we marked around the paper’s edge. Then we cut the wood with a jigsaw.

The door was placed against the front edge of the sandcastle, before we started placing the mud. Then we started packing mud around the sandcastle, being careful not to press inwards on the castle, and trying to maintain a mud thickness of 4″ all the way around. After we had surround the sandcastle with mud, we smoothed out all the bumps, and patted the surface down with a flat paddle made of wood, for an even finish.

Now we need to wait for the mud to dry – after which we will remove the door, and scoop out the sandcastle.

To be continued ….

Packing the mud around the sandcastle. Note the oven door.

Finishing the mud packing

Porsche 914s

It turns out that there are a quite a few Porsche 914 owners at Caltech. A few of us met up today: here are the assembled vehicles -

Quadcopter

I have just finished ordering the parts to build a Quadcopter, similar to the one shown in this clip:

The design I’ll use is based around an Arduino Duemilanove processor, and is called an AeroQuad. Here’s what I ordered, for a total of around $250:

Motors, Speed controller and Propellors

Four TowerPro BM2410-08T / 18A BEC / 9×3.8 Prop Combo

According to the HobbyKing table this motor should run at up to around 8900rpm at full voltage (10V). Plugging the size of the propellor (9 inches with a pitch of 3.8 inches) into this static thrust calculator, the thrust from each motor should be a maximum of 0.6kilos, so a total thrust of 4×0.6 = 2.4 kilos.

Battery

One Turnigy 2650mAh 3S 20C Lipo Pack

At around 11 Amps for each motor, maximum, the total will be 44 Amps. This battery should give a minimum operating time of (60*2.65)/44 = 3 minutes.

Radio Control Transmitter/Receiver

One Hobby King 2.4Ghz 6Ch Tx & Rx (Mode 1)

The “Mode 1″ refers to how the controls are laid out. Apparently in the USA, most pilots use Mode 2. Mode 1 looks like a more logical layout to me, and since I am not a pilot, is what I chose. The Transmitter/Receiver works at 2.4 GHz. One idea I have is to put an X10 RF Spycam I have on board the quadcopter: this also operates at 2.4GHz, but in analog, so there should be no interference. I also have an ICOM IC-R3 handheld I will be able to receive the X10 video stream on:

One Hobby King 2.4Ghz 6Ch Tx USB Cable for Win2000/XP

This interface cable allows the Transmitter to be controlled from a laptop/desktop.

Processor

Arduino Duemilanove with ATmega328

Sensors

One 5DOF add on board (X,Y,Z, Roll and Pitch)

One Dual Axis Gyro

The concept is that the sensors detect the position and orientation of the quadcopter, and the Arduino board runs software that uses this information, together with motion control signals from the Transmitter, to adjust the power going to each of the four motors. This in turn affects the thrust from each of the propellors, which produces the desired (or not!) motion of the quadcopter.

Nash Equilibrium

I was in a discussion the other day where the topic changed to Nash Equilibria, about which I knew nothing. Later investigation led me into Wikipedia vortex in which I discovered not only what a Nash Equilibrium is, but also that if you add a new road to a transport system then it can increase the congestion, rather than alleviate it. Who knew? Apparently this is a real phenomenon, and has been observed in various large cities around the world, and is called Braess Paradox.

Will I ever use my new found understanding of Nash Equilibrium? Quite possibly not, but it’s generally true that time spent investigating stuff like this is well spent. I recall reading about genetic algorithms years ago, and spending quite some time writing my own for fun (looking at the Travelling Salesman problem), never thinking that it would turn out to be useful in the future. Nowadays I use GAs a lot, for all sorts of problems.

Earlier on today, a chap contacted me and asked if his 1913 British Penny was worth anything. He included a picture of a very worn specimen, probably essentially worthless, and I told him so. Just because something is old, doesn’t mean it is valuable

On more pressing matters, Microsoft Security Essentials is asking me to reboot my machine, and I must obey. I love this MSE, so much better and less intrusive than that awful Symantec/Norton thing that I had before, and which seems to snarfle a significant fraction of my system resources.

The Oscars

As a veteran of watching these long drawn out proceedings, I can say with some confidence that this year’s was Yawnsville, Arizona. Why on earth we needed two not quite funny guys compering rather than just one is a puzzle. Bring back Billy Crystal.

I didn’t understand what had possessed James Cameron’s wife to wear that dress, and I couldn’t get my mind around the idea of Sandra Bullock being a decent actress. Seeing the Big Lebowski win was heartening, though, and the collection of horror films was very well done.

The only film that really demands to be seen is the “Up in the Air” thing with Clooney: it looks mighty entertaining.

Now Mitchell Has Gone …

Time for a new fish. A Six Line Wrasse – very colourful, quite cheeky.

Pasticcio got nowhere with Anna, so now it’s my go

You said: Do you have drawers?
Anna: Here you will find the Clothes organisers

You said: No, I mean drawers, you know, the ones you wear?
Anna: Here you will find the Clothes organisers.

You said: I’m curious about your underwear
Anna: Can I suggest that you use the internet, or a library, to find out more about this subject?

You said: I’d rather ask you directly
Anna: It’s difficult to talk about this properly as I’m really only programmed to talk about IKEA and our products and services.

You said: I know it’s difficult, and perhaps embarrassing, but I wish you’d try
Anna: Good. A positive attitude is essential.

You said: I think you’re being evasive. Are you wearing a bra?
Anna: You are perfectly entitled to hold any opinion you want about me. Furthermore, your comments improve my knowledge base. Thank you!

You said: How about you improve your knowledge base by showing me your chuff?
Anna: It might be nice to talk about that sometime, but for the moment let’s get back to talking about IKEA.

You said: If you just loosened another button on that t-shirt, I might get to see some cleavage
Anna: If you are missing anything from your purchase, all you need to do is return to your local IKEA store. Just go to the “Returns and Exchanges” desk with your original purchase receipt and a friendly co-worker will be happy to assist you.

You said: Perhaps a drink would help you mellow out a bit. I suggest a stiff one
Anna: Here you will find the Eating & drinking category.

You said: We have something in common: a one track mind
Anna: I’ll do my best.

You said: I’m guessing you are rather kinky, or is it wishful thinking?
Anna: I have a vast knowledge base with lots of information about IKEA, our products and services. Ask me a question about IKEA and test me yourself.

You said: Are you free for dinner after work tonight?
Anna: To which IKEA store are you referring to when asking about the restaurant?

You said: Please please please stop going on about IKEA. I want to get to know the real Anna.
Anna: Good. We’re reading from ‘the same page’ then as they say.

You said: We are? So how about we kiss with tongues?
Anna: I think you’re confused or trying to ask me a question, but I need more than that to give you a proper answer. Please try again.

You said: Now we’re getting somewhere! When can I sink my sausage?
Anna: Please take a look at Sinks.

You said: Yes, I will. I expect I’ll get more action with a sink than with you.
Anna: Please take a look at Sinks.

You said: I get the message. Au revoir!
Anna: Bye, then! It was very nice talking to you!

Brass and Bottoms at the Rose Parade

Once you’ve seen one X, you’ve seen ‘em all. Where X = floats, fannies, etc.. Again, this year, there was no stealth bomber doing a fly-by, which was disappointing. On the other hand there were lots of large brass instruments.

Mitchell is DEAD!

After a long, unhappy life pestering fellow fish, belligerently snapping at snails, harassing hermit crabs and gaping truculently through the glass at us, Mitchell has finally put his heckles down and gulped his last gulp of briney water.

Let us pause a moment and reflect on the epitome of unpleasantness he represented. He somehow distilled the essence of obnoxiousness (and we all have some of that in us, at least at a level) and be hopeful that that has died with Mitchell.

Ha! Fat chance.

HOORAH.

This day has not come soon enough for any of us. I shall now dance on his grave (the loo).

Holidays

Well, I haven’t updated on here for a while, and now it’s time for the holidays.

I will *not* be shopping at all at Best Buy in protest at their obnoxious pop-up ad that is making my LJ browsing a misery. Do they really think that by forcing me to watch their cruddy ad it will make me want to go in their shop? Guess again!

Collisions at the LHC!

Protons are colliding: min bias rate around 1Hz. This is the first physics run.

Watches

I have about ten watches which I don’t wear because the batteries have run out. All of these darned watches seem to use a different size of battery, none of which tend to be available in the places I normally look. So the watches sit unused.

Perhaps I should order new batteries online. But for the cost plus shipping, it’s almost the same price as buying a new (cheap) watch.

I’m really discombobulated by this predicament.

Cinq Questions

1. What brought you to the States?

Initially, I believe it was a Boeing 747-400. I had steak. I was going to Colorado Springs for a Digital Equipment Corporation customer jamboree. When we got there, it was snowing and cold. The next morning, it was 75F and sunny. This gave me a strange initial impression of America.

Later, when I moved her permanently, I came in a different model ‘plane. For a more complete description of why I came to Pasadena, you’d need to fish around in the archive of this LJ, something I don’t recommend unless you have trouble sleeping.

2. Do you love it, miss home, or a mixture of both?

Southern California is easily the best place to live in the world. Everything you ever want or need is here, except for really old buildings, and they are over-rated. There are some things about the UK I am nostalgic for. An example that occurred to me yesterday is Goddard’s Components, a little shop in St. Albans where you could buy electronic bits and pieces, like a BC108 transistor and an old computer board. Also there was a very good market on a Saturday. What I don’t miss is the damp, grey mornings and the ubiquity of plastic bags and sick in the gutters. Oh, and I miss custard tarts and the occasional Jaffa Cake.

I lived in Geneva for many years, and there is more I miss about there. For example the raclette and fondue and the sublime Italian food, the proximity to all the other countries, the view of Mont Blanc from everywhere, and the excellent skiing. On the other hand I don’t miss scraping an inch of ice off the windscreen in the morning, and the loony French drivers. Nor do I miss driving around the Pays de Gex on a Saturday trying to find a shop that sells a CD player before everywhere shuts at 4:30pm.

3. What do you think of Californians, and do you think they are typical Americans?

To me, a typical American is a guy in a loud check jacket, light blue trousers, and a pair of golf shoes. I haven’t seen anybody fitting this description in California, and I strongly suspect they are all in Salt Lake City.

4. Favorite foods

Haggis and chips (fries) with onion gravy. Caprese salad, with a crusty baguette. A thin crust pizza with pesto sauce, aubergines and pepperoni. And McVitie’s Milk Chocolate Digestive biscuits.

5. Are you now what you wanted to be when you grew up?

When I was growing up I had no idea what I wanted to be. I toyed with the idea of being a barrister, and I think I might have been quite good at it, as I enjoy a good argument. Another occupation I remember investigating was a Patent Officer, which is probably interesting at least part of the time. So somehow I gravitated towards physics (if you’ll excuse the pun), probably largely influenced by the fact that my Dad, who I admire, is a physicist.

Portland

Portland next week for a conference. Last time I was there, a few years ago, it pissed down almost continuously, which is perhaps why they gave all the attendees an umbrella!

Old Chaps at the Dermatologists

I overheard the following exchange yesterday, while in the waiting room to see this guy:

(or his spitting image. And no, I didn’t use the ‘phone.)

Old guy: “Hello Charles, how are you?”
Charles: “Oh, you know. How about you, Phil?”
Old guy (Phil): “Coming in for my regular. How often do you come in?”
Charles: “Twice a week.”
Phil: “Oh my God! You must be terrible!”
Charles: “Yup. I’m going straight to Hell.”

This amused me highly for some reason. Also Charles looked just like Harry Stanton:

Which brings me to the point of this post: increasingly I find that many people I meet or see remind me strongly of someone else. I’m forever saying “Ooooh, you know who s/he looks like? Bela Lugosi!” (although not always Bela Lugosi, obviously).

Anybody else suffer from this disease?!

Rummaging in drawers

My plan is to build another analogue synthesizer, but this time a modular one. I’ve been collecting the needed parts for a few years now, and am nearing the point where I can fire up the ‘scope, chauffe the old soldering iron (or “soddering iron”, as it’s known here) and start building circuits.

Something like this is what I’m thinking of (but probably not quite as professional):

South Pasadena Classic Car Show

Some very nice cars on show today down in South Pas. There was only one 914:

and only one Batmobile:

Man made Climate Change?

The climate change hoo-hah continues to alternately amuse and baffle me. The world’s climate has been changing for millions of years, so why any change at the moment is so shocking is beyond me. Of course the media love it: they pitch the nonsensical idea that mankind is somehow responsible. This notion just doesn’t stand up to common sense: the idea that we have any control over the climate is conceited and off-scale. Of course, if you live in a big city and notice the man made pollution you might be forgiven for naively assuming that everywhere else has the same levels of pollution. But if you’ve ever looked at a satellite image of the earth and seen how largely uninhabited it is, 2/3 of it covered by water, or looked out of the window on a transAtlantic flight, where you fly for hours and hours over desolate, completely uninhabited land, you see how pathetically insignificant a bit of pollution in a small area of a few hundreds of square miles is, and how ridiculous is the notion that our SUVs are affecting the global system.

So the climate is changing. Big deal. The latest article I read in the paper today had a title like “Arctic Ice Area at Third Lowest Since Records Began”. It turns out that the Arctic ice has actually been *increasing* in area over the last few years, and also that records began only in 1979! The third lowest in 20 measurements, and we are supposed to be alarmed? And I read somewhere else recently that, in fact, global temperatures have been *decreasing” over the last years. Unfortunately such news is not as exciting as “We Will All Fry To Crisps in 2010!”.

You can see from the graph that we aren’t yet up to medieval temperatures (which the media then would probably have blamed on oxen farts and witch bonfires).

Man made global warming is a load of tosh, and I’d love to be proved right

American Education

It’s no wonder I have been impressed so far by the American education system: Muffet’s school has just been recognised as one of the best in the country, with a Blue Ribbon award.

In other school related news, a high school friend uploaded this photo of me to FaceBook, taken around 1976, when I was in the Sixth Form. Check out the size of the lapels!

Hitler wants a uniform

I had some fun making this. Flagged for bad language in the subtitles.

Deep Fried Butter?!

I haven’t decided where I stand on this yet.

Huge Cloud

This huge cloud is appearing above the San Gabriel mountains. I wonder if it is related to the Station Fire?

While I was getting my double espresso from the campus cafe, I noticed on the TV that they were showing a piece about how pilots are on strike because they are fed up with having to relieve themselves in bags. My guess is that they are not allowed to emerge from their cockpit during the flight to visit the First Class loo.

How very demeaning that must be … and I fully sympathise with their plight. Many times I have sat on a ‘plane rather wishing I could go to the loo, but the constant stream of women who seem to have to visit it six times every hour for ten minutes a “job” prevents me from getting a look in. Many times I have yearned for a bag, and some privacy while I whip out the old todger and relieve myself into it.

The solution for the pilots is quite simple. Just install one of those tubes that department stores used to have for sending message around the building, running it between the First Class loo and the cockpit. The pilot would then simply uncap the tube, slash into it, and replace the cap. The liquid would emerge at the other end, where it would empty into the loo bowl. Perhaps a button in the cockpit could be provided so that the pilot could remote flush, if desired?

For women pilots, the solution is less obvious, but I suppose equally pressing. Some sort of gas-mask like contraption, placed over the business parts, might work, although clean up would be a problem.

There would also need to be some sort of interlock mechanism so that a First Class passenger seated on the loo could avoid being doused by a copious stream of warm pilot piss whilst they were in mid-wipe.

In which I fondle a long one

Quiz: which of my LJ friends owns the lens I am fondling in this photo?

The Chinaman's Nipple

Just back from a couple of lazy weeks, and trying to adjust to having to do stuff again.

Why I Like Google Android

Android is so easy to write little applications for, and is a delight if you are a Java fan! With the Android Eclipse plug in and the decent emulator provided, and the easy integration with the phone itself, the whole package is just convenient and efficient.

To take advantage of some of the new features in the latest Android SDK (1.5 “Cupcake”) I decided to flash my Google G1 Developer phone to the new release, earlier this week.

Since my phone was running 1.0, I needed to do this in two steps: first upgrade to 1.1, and then upgrade to 1.5. (I tried going directly to from 1.0 to 1.5, but it proved impossible – although it’s not clear why).

The instructions I used are here:

HTC – Support – Flashing your Android Dev Phone with a Factory System Image

The first step is to place the new radio image on the sdcard in the phone, using “adp push” from the desktop. Then the phone is rebooted into the management console, and the new image installed. Then the new system image is pushed to the phone, and installed in the same way.

This all went without a hitch, after I realised that the phone should not be mounted as a USB storage device during the process (otherwise the adp push commands to send the files to the sdcard from the desktop will fail with “no permission”).

I was surprised to find, after the upgrade, that all my installed application were still there, which was uber-cool.

Following the upgrade, yesterday I tinkered around with the Sensor API in the G1. In particular I was interested in the accelerometer, which provides real time measurement of acceleration in all three axes of the phone. It appears to be quite accurate. There are three or four built in interrogation rates for the sensor – I used “Normal”, as I was interested in making a seismometer, which doesn’t need very fast rates (I think the fastest is around 20ms per sample).

Over one lunchhour I was easily able to make the little app shown at the start of this post, and deploy it on the G1. It emulates a pen chart recorder, and shows three pens that plot the acceleration in X, Y and Z. The lines move from right to left. At the bottom of the screen is printed the latest measurement: time since start and X,Y,Z values.

UK Citizenship Test

This is insanely difficult:

http://www.ukcitizenshiptest.co.uk/

I got 14 out of 24 right, and failed. Good job I don’t need to pass it

Townsend Tennis Club

This was (is?) sort of tucked away at the back of St. Albans. My friend Chris and I would go up there to play tennis, and snigger at the old girls called Doris, who were all dressed in white, playing bowls very seriously. There was an old chap called Ted who ran the bar, and he had an enlightened attitude towards under-age drinking – namely, he didn’t care. Either that or he was so old he couldn’t judge what age we were. He would make these icy-cold bitter-shandy drinks that Chris and I would glug down after a game of tennis. Most of the tennis courts were grass, but there were a few that were shale, or something. Great clouds of red dust would come up when we ran across them, and by the end of the game we’d be covered in it. The changing rooms were in the pavilion, which was a wood frame building that smelled of old socks and soap. There was a table tennis table, a table football machine, and one of those TV tennis games with the little bars and the ponging noise. I loved it there and would happily get into a time machine now for a few hours of tennis followed by a couple of bitter shandies.

The Graduate

After the ceremony, we ate in a place called Las Iguanas in Brighton, which was good – I had some creamy coconut chicken thing with fried plantains.

Security Questions My Arse

Signing up for some online banking the other day, and getting invited to select from several “Security Questions” that would apparently enhance the safety of my “online banking experience”.

The questions had to be selected from a drop-down menu of four, if I remember:

1) The name of the mascot of your high school (In the UK we didn’t have “mascots”)
2) The town in which your father was born (No idea. I know the region, but not the town. I bet my daughters don’t know the town *I* was born in.)
3) The street you grew up on (I grew up on several)
4) Your favourite teacher (Didn’t have one)

Who thinks up these questions? Isn’t it possible to come up with a set that everyone can answer? Or (the best option) allow me to choose my own security questions?

Perhaps it’s not so easy. Let’s see:

1) The name of the nasty boy who stole your James Bond DB5 Corgi toy and hid it in his underpants
2) The location of the first embarassing pimple that appeared on your pubescent chin
3) The name of that girl who showed you her fanny behind the bike sheds
4) Your favourite licquorice allsort
5) The word your first girl/boyfriend used to describe your private parts
6) The alcoholic drink you first got pie-eyed on