Light - like sausages?

I have just read the article in New Scientist about twisted light. It needs re-reading. https://www.newscientist.com/article/mg22429954.600-twisted-light-sends-mozart-record-distance-through-air/

It got me thinking about the dual nature of light- waves and particles. This article does not mention the particle nature of light. But consider that waves are not light travelling in a sinusoidal path, but really a measure of the magnitude or density of the light at that point. That's where sausages come in. A stream of sausage meat coming out of a machine has dense bits which are the sausage and is then squeezed down to nothing  and rises again. Now if the contents of this are particles, it means that at high amplitudes of the light wave, we have a high density of particles.

Another  aspect of the wave nature of light is that if light travelled in a wave motion, it would be travelling faster than light.

How can I consider the varying density of  light particles in the dual slit experiment?

Also have to consider how this fits in with polarisation and phase shifting. Colours of light are due to the frequency of the waves,

Thinking about phase, this article does not make it clear, actually it confuses the issue, about the form of phase shifting that occurs.  One type is horizontal, where the peak arrives at a slightly different time and the other I'll call angular, where the wave is at a different angle for the reference wave.

Forms of Government

DEMOCRACY: The United Kingdom (UK) is a democracy. A democracy is a country where the people choose their government. In the UK there are too many people to ask and too many decisions to take therefore representatives are elected to make decisions.  from http://www.bbc.co.uk/education/guides/zwvqtfr/revision

This is the form of government created and developed by the British over eight hundred years since the Magna Carta and used in most of the free countries of the world.

AUTOCRACY: government in which one person has uncontrolled or unlimited authority over others; the government or power of an absolute monarch.
from: http://www.dictionary.com/browse/autocracy

PLUTOCRACY: a government or state in which the wealthy class rules.
http://www.dictionary.com/browse/plutocracy

OLIGARCHY: a form of government in which all power is vested in a few persons or in adominant 
class or clique; government by the few. From: http://www.dictionary.com/browse/oligarchy

This is how Daniel Hannan identified the EU. This form of government is not used anywhere else in the world and is too cumbersome, with no direct lines of responsibility for any action. 

And from Wikipedia:
The EU treaties declare the EU to be based on representative democracy, and direct elections take place to the European Parliament. The Parliament, together with the Council, form the legislative arm of the EU. The Council is composed of national governments, thus representing the intergovernmental nature of the EU. Laws are proposed by the European Commission which is appointed by and accountable to the Parliament and Council although it has very few executive powers.

Note who proposes the laws: An Appointed body, not elected. 


The EU operates through a hybrid system of supranational and intergovernmental decision-making.^[17][18] The seven principal decision-making bodies—known as the institutions of the European Union—are the European Council, the Council of the European Union, the European Parliament, the European Commission, the Court of Justice of the European Union, theEuropean Central Bank, and the European Court of Auditors.  from https://en.wikipedia.org/wiki/European_Union.

For me that it too many bodies trying to take over too much. 

In Russia, there is a constitution that protects the rights of the citizen,  and people voted for it, but I cannot find anything that says how democratic Russia is. 

Voting Day- Brexit response to Facebook Post

This morning I was upset to see a proud post from my distant cousin that the labour party had given her to post, saying that she had voted to Remain. I was tempted to respond, but didn't. My response would have been:

1. This shows how the British educational system has gone wrong. These students have no idea of the History that has gone into making Great Britain what it is. It must be socialist teachers (Guardian readers) teaching of how we have benevolent  leaders in Brussels.

2. You believed Cameron's lies?

3. You are happy to be a slave to unelected leaders in a foreign country. This sounds like Totalitarianism.

4. You obviously believe that the graph showing GB's contributions to the EU has peaked, whereas everybody else thinks that the EU will demand more and more until they drive GB into poverty.


Friday after the vote:

http://www.telegraph.co.uk/news/2016/06/24/the-european-elite-forgot-that-democracy-is-the-one-thing-britai/                        Charles Moore.


I need to keep a link to this. it is a most powerful video about what the EU thinks is the future of England - see about 19 minutes. https://www.youtube.com/watch?v=BCBq0gloK-4&feature=share

Brexit for Scientists

According to this report: https://royalsociety.org/~/media/policy/projects/eu-uk-funding/uk-membership-of-eu.pdf

The UK gives a lot of money to the EU (2007-13) £77.7B, of which £5.4B is allocated to Science Spending.  (6.9% of £77.7B)

The UK receives £8.8B Back from the EU from this science budget. Therefore according to Scientists, we should remain because we are better off. We don't want to lose our science budget.

BUT, this £8.8B is only 3% of the money spent on science in the UK. The rest comes direct from UK sources.

So If we came out - Brexit, and were able to double the amount that Science had had from the EU, say to £18B,  (23% of the 77.7B) The UK would still have ~£60B to spend on other things, like the NHS, any tax barriers to EU trade, or whatever.

Advantages to Remaining in the EU

Well, We could save a lot of money by dispensing with our parliament and just being ruled by nameless unelected bureaucrats from Brussels. This in effect means cancelling Magna Carta. Common law is defunct.

What was spent on parliament can be used to fund the NHS.

Don't worry about Habeas Corpus any more, you can be locked up indefinitely without trial.

Before you do anything, check whether it is legal, because that is different from our current system, where you can do anything unless it is illegal.

Currently for working people our holidays and benefits are better than elsewhere in Europe, maybe we will have to downgrade?

David Cameron for Brexit?

On Sunday 29th Countryfile, David Cameron was being interviewed by the Countryfile Presenter Tom. Cameron replied to a question that sheep/cattle farmers should stay in the EU because they could sell into the whole EU easily, but the EU did not have any trading agreements with other countries for farmers to trade with the rest of the world. This sounds like an argument for Brexit surely?

I just had to make a note of this, because I wondered if anyone else had noted that.


8 june '16 In the papers in the last couple of days:

http://www.telegraph.co.uk/business/2016/06/05/economic-arguments-about-brexit-have-succumbed-to-group-think/                         We like Roger Bootle.

and

http://www.theglobeandmail.com/news/world/embracing-role-as-eus-de-facto-leader-germany-expands-its-army/article30282688/               Shades of 1930. Will we have the luftwaffe on Britain's air bases?

10 June: From my Capital & Conflict  newsmail:

But what about Brexit?

If Goldman is worried that Brexit is one of the “concerns” that could lead to a 20% drawdown in stocks, should you be worried too? Chancellor George Osborne says yes. Showing the fortitude and perseverance that have characterised the British attitude toward adversity, Osborne told the BBC last night, “there’s a lot to be scared about.”

How Churchillian. 

He was responding to allegations that he and the prime minister have engaged in a scare-mongering campaign to persuade the British public to vote Remain in the referendum on European Union membership on 23 June. Appearing on the BBC, Osborne said, “If we vote to leave, then we lose control... If we lose control of the economy, we lose control of everything. People should be under no illusions.” 

Control of their own economic and political future is precisely what the British people can get if they vote to leave. Also, note to chancellor: the government doesn’t control the economy and we don’t want the government to have “control of everything.” 

He’s right about one thing. People should be under no illusions that when push comes to shove, a certain species of political conservative reveals its preference for arguments from authority. If we’ve learned anything this week, it’s that Cameron and Osborne don’t believe the British people can be trusted. 

To be fair, the elites on the left and the right are united in this belief these days: you don’t know what’s best for you so you need to be told. This is not your Britain. 

Ever the voice of calm reason, The Fleet Street Letter’s Charlie Morris had something to say about Brexit in his latest update. Charlie commented that both the pound and the euro had rallied against the US dollar on the back of a weak jobs report last Friday in America. Then he wrote:

This is important because despite a shift in the polls towards Brexit, the pound hasn’t collapsed at all. The scare mongering campaign, otherwise known as “Project Fear”, is hugely exaggerating events. If Britain votes to leave, life will continue as normal. There will be a period of renegotiation, and a new agreement will be reached. The fall out – if there is any – will not come from Britain leaving. It will come from a diminished EU as other European nations follow Britain’s lead.

I won’t publish the rest of Charlie’s analysis (which is available to FSL readers). But the last point gets to the heart of the matter. For Charlie, this is your Britain. 

Elites in British public life and elites at organisations like the IMF, OECD, the World Bank, Goldman Sachs and JP Morgan all want to remain because it’s good for them. They make the rules for the rest of us and live a largely separate life, benefitting immensely from the financialisation of the economy (and from huge and perpetual public debts).

No wonder they don’t want any change. The status quo is good for those at the top. And it keeps everyone in their proper place. If Britain bolts from the EU, the stampede will be on (see Soros below). It will be the high-water mark for the whole European project in its current, anti-democratic, bureaucratic, highly-regulated form. And that’s not a bad thing. Why?

The project will be forced to evolve into something the people of Britain and Europe find more useful (and more accountable). In nature, apex predators don’t have to adapt. They’re at the top of the food chain. They kill what they want. When you’re the king of the jungle, it’s good to be the king. 

Brexit is an external event (like the meteor that killed the dinosaurs) which threatens the current unnatural political order in Europe. British and EU political elites are acting like annoyed and cornered predators. Annoyed because they have to lower themselves to seek the public’s approval. Cornered because now that they’ve left the result to democratic forces, it’s beyond their control. 

And as Osborne said last night, it’s about control, isn’t it? 
 

Thoughts about Brexit

It seems that older people are in favour of leaving the EU, and in general younger people are going to vote to stay in. Well, I have two thoughts about this.

1. The young should consult the old and find out why they want to leave. Usually it is because they voted for a European economic community (which isn't working) and didn't want to have rules of a European political entity imposed on them by faceless unelected bureaucrats.

2. The young do not have a spirit of adventure, and are not willing to face new challenges. The world has changed from the constancy of the 1970's and is very volatile. Britain should become it's own nation again and use the spirit of Nelson and Drake to become it's own master once again.

24/4/16 Barack Obama has just come to the UK and told us how to vote, thus antagonizing a whole bunch of brits that don't like being told what to do by a foreigner. But the question is, what does David Cameron have to do to pay POTUS for coming over and making that speech?

2/5/16 from the Capital & Conflict email: [It's quite strong. I had to put it all.]

Save British Justice

By Christopher Gill

“Safer, stronger and better off” says the prime minister, to which one might retort “how can we possibly be safer if, as might potentially happen to any one of us, we can be arrested without the least shred of evidence that we have indeed committed an offence.”

Not many people know that this is the current state of affairs and, for reasons that are not hard to discern, neither the PM nor his sycophantic ministers want us to know! In spite of the best efforts of those of us who are totally opposed to any dilution or abandonment of the defences which, heretofore, have ensured that individual British subjects are protected against state-inspired coercion, in November 2014 the government led by David Cameron took steps to reconfirm Britain’s support for the iniquitous European Arrest Warrant (EAW). 

Cameron did not need to do this – no treaty obligations would have been broken if he had simply said “thanks, but no thanks” – but he did so in spite of substantial opposition from his own backbenchers and while all the time hypocritically saying he wanted to see powers repatriated back to the UK!

The power that he gratuitously and wantonly gave away to the totalitarian European Union is the power of the state to deprive its citizens of their liberty – in other words, the ultimate power of statehood – and he gave it away to a group of nations whose criminal justice systems, with the honourable exceptions of Ireland and Malta, are totally alien to our own and whose shameful record of incarcerating entirely innocent people speaks for itself. 

The learned opinion of Jonathan Fisher QC (see www.tfa.net under Publications/Research) is that the EAW negates the law of habeas corpus – the law of habeas corpus once having been described on Radio 4, by no lesser person than Archbishop Desmond Tutu, as “such an incredible part of freedom”.

The simple reason why habeas corpus was “such an incredible part of freedom” was because it prevented the powers-that-be from arresting a suspect unless, within 24 hours, they could produce evidence, in open court, that the accused had in fact committed an offence and were thus able to charge him or her accordingly.

During the parliamentary passage of the Extradition Bill, which in 2003 put the EAW onto the statute book , government justified its actions by claiming that there was an “equivalence” between UK law and that extant in other EU member states – an equivalence that, frankly, didn’t exist then and doesn’t exist now!

All the defences and protections against false accusation, arbitrary arrest and wrongful imprisonment, that have historically been enjoyed by defendants in the UK and other common law countries, such as trial by jury; the presumption of innocence; the right to silence; the inadmissibility of hearsay evidence; the withholding of the defendant’s previous convictions; press reporting restrictions and (until recently) protection against double jeopardy; not to mention the aforesaid law of habeas corpus, are virtually unknown in continental Europe.

The EU’s concept of a just and equitable criminal justice system is their embryonic corpus juris which mirrors the criminal justice systems extant on the continent, modelled upon the “Code Napoléon” with its roots in the Inquisition and certainly not, as with our own system, with its roots in Magna Carta. 

Ironically, while in 1215 the barons were prevailing upon King John to append the royal seal to Magna Carta, the pope in Rome was at the very same time imposing the Holy Inquisition. To this day the continental systems of criminal justice remain “inquisitorial”, with the onus upon defendants to prove their innocence, which is, of course, totally contrary to the “adversarial” systems of common law countries where the onus is firmly upon the prosecution to establish guilt.

Another little known feature of the EU’s contingency planning is the establishment of the office of European Public Prosecutor (EPP) who will be superior to all national public prosecutors and who will, of course, do the bidding of his EU political masters. 

Work on the establishment of the office of EPP is scheduled in the current EU work programme but is highly unlikely to manifest itself before 23 June for fear of frightening the horses (ie, the British electorate who are, as yet, blissfully ignorant of the repressive legal system which will almost certainly be imposed upon us should we be foolish enough to vote to remain within the benighted EU).

Already in being is the European Gendarmerie Force (see www.eurogendfor.eu) – an EU organisation with its training facilities at Vicenza in Italy. What possible use could be envisaged for such an armed para-military force other than to ensure that the EU’s writ is enforced throughout its territories? In this connection let us not forget that James Brokenshire MP, a Conservative Home Office Minister in the last parliament, in answer to a parliamentary question by Dominic Raab MP, stated that HMG would be prepared to invite “special intervention forces” (aka the EGF) onto British soil if the need arose. The problem with that is that once here the EGF, being answerable only to Brussels, would leave only if ordered by Brussels to do so. In other words we would effectively be under EU occupation.

The only way to be sure that the horrors I have outlined above – “the elephant in the room” that our prime minister and others of his persuasion do not wish us to see – do not deprive us and generations as yet unborn of our individual freedom, is to vote to leave. As someone once famously said, “the price of freedom is eternal vigilance” and never was vigilance more necessary than at the present time!


And add Theo Paphitis  (Dragon's Den) thoughts
The IMF’s article titled ‘Exit could cause severe damage’ (BBC.co.uk) was rather misleading, as the key point is surely that a ‘UK exit from the EU would “disrupt and reduce mutual trade and financial flows’.  Scaremongering again.  This story’s true meaning actually does far more for the Vote Leave campaign and some of the conjecture out there.

http://www.theopaphitis.com/theos-blog-walking-and-chewing-gum-at-the-same-time/

[6/5/15] From Daniel Hannan Book A Doomed marriage:

Margaret Thatcher observed that Britain's problems had come from Europe, and the solutions from the rest of the world. 

Also that before we joined the EU, we controlled 75%? of the fisheries around Britain, now the EU controls it and we have access to only a small portion.

8 May 2016 - Michael Gove on the Andrew Marr Show

Gove said that we give so Many Billions to the EU, Andrew Marr replied that we get a lot of it back.
Gove replied that we get back what they want to give us, and without guarantees, and the EU could change it, and also that they tell us where to spend it. 

What he didn't say is that if we Remain, they could put up our contribution. 

11 May 16  - Are we Fools? 

http://www.telegraph.co.uk/business/2016/05/10/government-treating-uk-public-like-fools-in-brexit-debate-says-f/

Following on from Trevors posts on FB I have been looking into the fisheries. The UK used to have a lot of fishing areas, but the EU has assigned areas so that we have a lot fewer. They have also put in a quota system which can be considered good as it has helped stocks to grow. A  recent article http://www.telegraph.co.uk/comment/11305123/No-end-to-the-EUs-crazy-fishing-policy.html implies that this has destroyed Britain's Fishing fleet, but this article says that it was good: https://www.opendemocracy.net/can-europe-make-it/griffin-carpenter/eu-common-fisheries-policy-has-helped-not-harmed-uk-fisheries-0 

So I don't know what to believe. 

13 May 2016   And Hargreaves Speaks out:

Peter Hargreaves is willing to take the other side of the trader. The billionaire owner of Hargreaves Lansdown told The Guardian that a vote to leave will be like Dunkirk again. That was eerily familiar. The Fleet Street Letter Investment Director Charlie Morris was all over “the financial Dunkirk moment” Brexit has brought us to, months ago. 

Hargreaves used the same metaphor. But he means something different. He suggested that the very uncertainty created by Brexit will be a catalyst for positive change. It’s like Brexit is a disruptive technology. He says:

It would be the biggest stimulus to get our butts in gear that we have ever had… It will be like Dunkirk again… We will get out there and we will be become incredibly successful because we will be insecure again. And insecurity is fantastic… All the people in the City of London who I rate and are intelligent and talk sense actually say it would better if we left… All the government lackeys, all the bureaucrats and the people on the boards [who] haven’t got a clue what they are talking about want us to remain.

RC-Car-1 RAspberry Pi to drive ex-RC car

27-10-17 New comments at end.
------------------------------------------

22-2-16, Finally got Raspbian Jessie wirelessly connected to network on IP 192.168.1.8.  errors and struggle was due to wrong ESSID. [note _ instead of - ]

 I have installed Apache as per the instructions I am currently following. and have connected to apache base page.

see:

http://raspberrywebserver.com/gpio/piface/building-a-remote-control-vehicle-using-a-raspberry-pi.html

27-2-16 Testing basic html on R-Pi.    Have nicked  buttons from here as the ones that I found didn’t format nicely.  These do OK.

Now I have taken my LED blink program that tested three GPIO ports and edited it so that different buttons  with different GPIOs. On each prog I have cut out two ports. I have  read up how to call Python direct from HTML, which seems to use CGI anyway.   This needs testing.

I have discovered that the connections on my GPIO breakout box are correctly labelled. the labels P17 stand for GPIO17 which is actually pin 11 on the GPIO pins.

The programs now refer to that in the naming as blink17/22/23.

Then things like how to terminate the python program when you leave the button for left/right, and how the stop will stop the forward action.

I have just discovered that I have a permissions problem with the blink programs.  ssh into it and change permissions of the blinkxx.py files to 777. It still just lists the files.

1/3/16 Have asked question of the web site above, but no response yet. Am looking at

http://davstott.me.uk/index.php/2013/03/17/raspberry-pi-controlling-gpio-from-the-web/

but he uses a feature called fastcgi. that is more complex.

and:

https://www.raspberrypi.org/forums/viewtopic.php?f=31&t=96200 has some comments. I haven’t tried it yet.

---------------------------  ----------------------

3/4/16 I have made two attempts using samples that I found on the Internet.

This attempt number three

26/3/16 This one is going to be developed using the notes from

http://www.cardboard-car.com/en/top-story-en/raspberry-pi-robot-steering-internet-smartphone/6961

and mostly from

http://webiopi.trouch.com/

27/3/16 New card; Raspbian Jessie 18/3/16, wired into router, IP=192.168.1.19 (found with fing from tablet)

ssh into it,

Ssh -l pi 192.168.1.19 from Drive/R-Pi-initial setup

then expand filesystem using sudo raspi-config, and reboot

Sudo apt-get update

Sudo apt-get upgrade

sudo apt-get install zd1211-firmware

sudo apt-get wpasupplicant  [ though it may already have the latest]

sudo apt-get install lighttpd

configure network from Drive/wireless Configuration

configure wpa-supplicant using nano on the unit.

reboot wireless

For once it worked first time

how do I get WebIoPi tar file on to the R-Pi? Download it to kubuntu, copy it on to the SD card, and:

It is very easy to install WebIOPi on the Raspberry Pi. You have to download the WebIOPi file from the WebIOPi homepage and extract the file. After this you have to install WebIOPi and that is it. To do so you need a few commands I listed here:

The command to extract the WebIOPi tar file: tar zxvf WebIOPi-0.7.0.tar.gz

Now you have to change the directory to the folder where the WebIOPi files are extracted to.

With the next command you will install WebIOPi on your Raspberry Pi:

[sudo python setup.py install]    Invalid 
sudo ./setup.sh    works     [13/11/2017]

Now WebIOPi is available and can be used.

------------ ------------ ------------

WebIOPi successfully installed

* To start WebIOPi foreground : sudo webiopi [-h] [-c config] [-l log] [-s script] [-d] [port]

* To start WebIOPi background : sudo /etc/init.d/webiopi start

* To start WebIOPi at boot : sudo update-rc.d webiopi defaults      - must do this next time I connect to th R-Pi

----------- ----------- -------------

Put rapi_car_webio.html in www/html directory and it was picked up by browser.

So far so good. 

Hardware:
Had a look at the car. The rear wheels are driven via relays, and it looks like one of the inputs to the circuit is via a capacitor, even though they are DC motors. There is a chip that does all the intelligent stuff from receiving the RF signal to driving outputs. [SCRX2FS] Unfortunately, the spec sheet for this chip is in Chinese, but the pinouts are in English, so perhaps I can sort that out.

Here is a picture of both sides of the PC board in these cars. In the two relays the lines to the rear wheels are held at ground unless a relay is energised, then the motor drives. I have noticed that the line to the motor from one relay goes through a capacitor, so I wonder if they are driven by PWM as many seem to be.

Just southwest of the IC are two surface mount transistors that switch the relays (Q2, Q3). The multiple wires (blue,green,orange,yellow,red) run to the front wheel steering module. I don't know how they work. 

[6 April 16] From the spec sheet I found at the bottom a circuit diagram.

This shows which pinouts of the chip drive what.  [I am not sure how to make this image darker].

It does show me how For [11] and Back[10] drive the rear wheels, and Left [7] and Right [6] steer. 

I just need to know what all these other lines running to the steering box do. Guess it's time to open it up.   Blue and Green drive the motor. Brown, orange, yellow, and red are a Gray code wheel with brown as the common, for feedback.  That's not in this circuit diagram! 

My current thoughts are that If I remove the chip, I can use those pinouts to drive the motors directly from the Raspberry Pi. 

[10 April 16] Current problems are working out how this gray code thing on the steering works as feedback  for the control. As I have no circuit diagram it is difficult.

Secondly, looking at the python code for driving the car, it has two drive motors, one for each side and steers by adjusting the PWM for these motors. I'll try it just to see if it works before modifying it. 

[12 April 16] No, I need to modify the code, or else if I try it it will turn as well as go. I need to separate the two functions. Motor 1 is driven by pins 22 and 27, Motor 2 by 24 & 25.  What I propose is to change the code in the sections for Forward/Back Left and Right to Motor 1 being forward and back, motor 2 being Left/Right. 

[15 April 16] edited rapi_car_webio.py file to comment out the motors that I did not want to drive for forward/reverse/left and right. 

now need to test with LEDs

[19 April 16] connected LEDs to pins 24 & 25, set webipoi to run at startup, and also started it, but couldn't get LEDs to light. Must put in modified Python Program to test.

[20 April 16] Noticed that the HTML program does not call the Python Program. Funny. Look again and look at the webIOPi site and see how it should work, otherwise ask author of cardboard car.

The Python Program should be called script.py  and edit /etc/webiopi/config  to specify locations. 

[24 April 16] searched for webiopi debugging on internet and found

 https://www.raspberrypi.org/forums/viewtopic.php?f=37t=78471  This indicates that I also need to edit  /etc/init.d/webiopi  to specify file names and restart service. Didn't find this in webiopi instructions. 

Debugging output commands suggested after doing this are 'systemctl status webiopi.service' and 'journalctl -xn'.


[13 June 16]  On one of the PCB's I ripped out the chip and connected a USB connector to the 5v and Ground contacts. On the two tabs out of the chip to the Transistors for the rear motor I connected wires. I touched these to the +,gnd and the motors jumped - well and good. 

On another set of back wheels without the PCB, I touched +3 volts to it and the wheels spun- Therefore it is a direct drive motor and not a PCM driven one. 


[Oct 27 2017]  Have been struggling to find a battery to drive the motors, but I picked up another RC car at the tip and it contained a Li-Ion battery. A real treasure of a find. I have  charged it up using a 9 Volt/ 0.8 Amp power supply and a 100 ohm resistor, and soldered the leads out of my new find onto the board of my RC car. It all works a treat. It goes very fast, so I think I'll have to look into some sort of PCM speed control. This is available in webIOPI.  

Comments on charging: I found a 4 pin square connector from an old PC PSU, and two of the pins were in the correct orientation for the plug on the battery so it was cut down to provide the charger connector.   I monitored both the current and the voltage on a couple of power supply units before using this one. 

[Nov 9, 2017] Observations. 
It works, But has no speed control. Forward is forward at full speed, as is reverse, and Left and right immediately crank the wheels over hard until I stop them, which usually means it has done at least one complete circle. In  script.py There is  no code about them, so I have added lines to control the turning and switch it off after 300msec. 

But so far I am pleased.

[10/11/17]  I can't stop. I now have put in Left/right turn controls with 300msec  bursts of turn into the python script, and it works on the LED test rig. Must try it in the car now. For the record, this is SD card #4.