Green Screen

So I tried to do the green screen pictures today, however I think it would have been better to pick out the background image we wanted first as we aren’t quite looking in the correct place.

 

Have a little look on the site for more background pictures we could use over the weekend and then we can always do more ‘greenscreening’ on Monday or Tuesday 🙂

 

 

 

Session 4

Wow! What a busy day we’ve had.

  • Lots of group discussion about our presentation, which you wrote on the sugar paper and Ellie has typed up into the beginnings of a school-themed presentation – thank you! How will you fit everything you want to say into 3 minutes? All those jokes about Pi..
  • Estelle has done lots of fabric sorting and pattern cutting to get Ada’s 2 outfits ready. Luca built the “body and head” chassis so we’re getting there quickly.
  • Yusef & Lulu did lots of hard work on the speed chassis – the engineering bit is hard, eh?
  • Miss Gillan, Isabella and Klaidi have made amazing progress with the dance! And Miss Parsons came in to cast an expert eye over the choreography which was really helpful, thank you!
  • Mmm, also we ate. ALOT! But it gave us the energy we needed to keep going.

 

Dressing Ada

I have started a collection of bits and bobs we could use to dress Ada. I don’t have any purple silky fabric for her dress, but if we can’t find any we could use tissue paper. See what you can find at home (ask first!) to add to the tin? We also need a funky disco outfit. I found some googly eyes!

This week

Remember – the presentation needs to be handed in soon so this needs to be created this week.

 

Also, I will be in the ICT suite each lunchtime, Mon through to Thurs (after choir). I’m hoping to see you at some point in there 🙂

Obviously I don’t expect you every lunchtime as we all need a break every now and then 🙂

 

Can’t wait to continue with this! The competition is getting much closer – Getting excited!

Ada Speeds up!

Here are some photos and videos of Ada’s adventures with E!  Well done E & her Dad! Can you see how the speed chassis is different? Why does it go faster? What makes it keep straight?

Lulu & Yusef – you will be able to experiment next week and see what you can come up with! Hopefully this will give you lots of ideas.

This is Ada with her original chassis:

Ada speed test

This is Ada on her speed chassis, which is all made out of spare parts so we don’t even need to take her apart in between challenges:

speedy Ada1

More speed

I think this is the best way to solve the gearing:

I have tried it with my EV3 robot and it goes very, very fast. The instructions are for the EV3 (the new robots) but we should be able to adapt it for Ada (she’s an NXT!)

However, it keeps going off course. I emailed Prachi and she suggested changing the build so that Ada is as low to the ground as possible and has a shape like a fish or an aeroplane. I think it’s difficult to go fast and straight so we will need to find a good balance between the 2.

If possible, we need to build a “speed frame” out of the spare parts (there are 2 spare wheels) so that in between challenges we just need to disconnect the brick from Ada and clip it on to the speed frame for that challenge. That way we won’t get too rushed and confused by taking Ada completely apart and rebuilding her.

Other suggestions:

  • Use only one motor and one axle so the wheels move together (do we need 2 motors to go faster? If 2 people run and hold hands, do they go any faster?)
  • Try 4 wheels? Not sure if this would help it go straighter?
  • Keep the design low to the ground and aerodynamic
  • Ensure the brick is directly over the wheels to get the centre of gravity right

 

Half term

During the holidays, have lots of fun!

If you get bored you could look at some Lego Build projects online, see if you can find any speed machines?! There are some links on this blog, here.

You could also try to understand the maths behind the wheel rotations for distance travelled. Read the Ada sheet I gave you and here are a couple of challenges:

  • My bike wheels are 60cm diameter. From my house to school is 2km. How many times do my bike wheels rotate on the journey?
  • My car tyre is 65cm diameter. My parents live in Cheshire – 340 km from Wimbledon. How many times do the car wheels rotate on my journey home?
  • Did you do any car journeys in the holidays? How far did you go and how wide is your car wheel? Can you work out the wheel rotations?! (Don’t measure the car wheel size by yourself, get an adult to do it or just estimate)

(Don’t forget to convert all the units of measurement to be the same first!)

You can email me the answers or any questions – nic.schofield@mertonpark.merton.sch.uk

 

Session 3

So, we did lots more Pi revision in this session and we practised some X Factor challenges that Miss Gillan made. We confirmed that we would be choosing Ada Lovelace as our theme and we chatted a bit about the challenges.

We were delighted that St Mary’s school has loaned us some robots but they don’t quite work so I’ll take them home over half term and try to fix them. And the thrilling news is that Murphy Surveys bought us 2 new EV3 robots to use after the competition!

Who was Ada?

800px-Ada_Lovelace_portrait

On 11th October each year, we celebrate the life of Lady Ada Lovelace, who is known as the world’s first computer programmer. She lived from 1815-1852 and was the daughter of the British poet, Lord Byron, whom she never knew. He was described as “Mad, bad and dangerous to know”, so Ada’s mother is thought to have encouraged her daughter to concentrate on mathematics – the “opposite” of poetry, to ensure she was calm and good. (Is it really the opposite of poetry? What do you think?!).

She worked with the British mathematician, Charles Babbage, who invented & built the Difference Engine, which was a machine for performing mathematical calculations – like a calculator but many times bigger than the ones you are used to!  He also invented the Analytical Engine, which was more like a computer because it could be programmed and it was this that Ada wrote the first algorithm for, but this was never built.  As you know, the Victorian Age was a time of great inventions and thinking. Watch the clip below:

math

Babbage had been given a lot of money by parliament to build his earlier machine (£17,000 – the cost of 2 Royal Navy warships!) and the politicians wouldn’t give him any more. Ada offered to take over the running of the project, in order to get the money to continue, but Babbage said, “No”. So, (cover your ears!) Ada turned to gambling on the horses to try and win the money. Children, the gambling didn’t end well (it never does).

Ada died young, but she left some notes containing what many consider to be the first computer program—that is, an algorithm designed to be carried out by a machine. She also imagined that computers could go beyond mere number-crunching, while others, including Babbage himself, focused only on that. Her mind-set of “poetical science” led her to ask questions about the Analytical Engine, such as that it could be further developed to program music and solve other problems.

She understood that the Analytical Engine could perform more complicated processes than adding and subtracting – it could calculate things that hadn’t been previously calculated by a human first. She also understood that it could do a lot more than produce maths tables – it could create art, music etc if only it was programmed in right way. This was “truly visionary” and a “massive conceptual leap” – in fact it was describing the computers we use today. It was a futuristic idea (think of the film “Back to the Future”!). No-one really understood what she meant. She visited weaving mills in the North of England to copy some of their technology eg punched cards. I like that she applied the technology from one idea to another (My favourite question – “What else could this be used for?” Think of a toaster, an iron, a whirly-gig washing line…).

Watch the clip about Ada below:

ada legacy

There is a computer language named after her, called Ada, and it is still used today – for example in air traffic control. So, the next time you fly, think of Ada!

We celebrate Ada’s life in Code Club by programming a machine that Ada may have liked (but her mother may not have approved of!) in Scratch.

code

 

Sources: BBC Clips, Radio 4 Great Lives, Wikipedia

Session 2 – Moving & Turning

We welcomed Lauren from IBM, who had a very interesting discussion with the children about her engineering background.

We agreed our teams (are these correct?):

X Factor Challenge – Ellie & Luca (need to learn all sensors – see Miss Gillan at Thurs lunchtime)

Speed Challenge – Lulu & Yusef (with help from Klaidi)

Best Dressed Robot – Estelle & Luca (with help from everyone)

Dancing Robot – Isabella and Klaidi (with help from Estelle)

Presentation – Klaidi & Isabella (with help from Ellie)

We discussed methods of travelling a set distance and how to calculate wheel rotations required for travelling and for turning. Then we programmed our robot to travel round a maze. It wasn’t as accurate as we had hoped – maybe the carpet’s fault?!

IMG_3295 IMG_3292

Sam (Izzytea) helped us think about gearing up the robot wheels for the speed challenge (see this example too):

IMG_3294 IMG_3293

 

Turning the robot

There are 2 types of turn:

  1. Pivot/ Point turn
    • the axis of rotation is the centre of the robot, and 2 motors are used – one to turn each wheel.
    • The steering lever is pushed over to one side
    • The number of Rotations is used to determine how far the robot turns.
    • To calculate the required number of Rotations, divide the circumference of the robot turning circle (robot diameter x Pi) by the wheel circumference (diameter x Pi).
    • With Ada using the normal tyres, the number of rotations is 2.09 for 360 degrees, and divide for smaller angles eg 90 degrees is 2.09/4.
    • The maths investigation we discussed is here as a refresher! (remember to think of Lulu (1.45m tall) doing a forwards roll!).
  2. One wheel / Swing turn – only one wheel and one motor is used to turn the robot – the other wheel is stopped during the turn. The axis of rotation is the stopped wheel and the distance traveled is further. In this case, the distance traveled by the moving wheel will trace a circular path of which the diameter is equal to TWICE the distance between the wheels. Yusef thought it might be helpful to use this turn at speed. We will investigate.

There is more explanation here DrivingTurning (2) but we need to discuss the programming on the last page of this.

Moving a set distance in a straight line

We discussed & tested 3 methods to program our robot to move a set distance in a straight line:

  1. “Trial & Error” – guess the distance, test then adjust however necessary until the given distance is achieved. Adjust Power & Seconds to reach your destination.
  2. “Maths Measuring” – accurately measure the distance you wish to travel, and divide this number by the circumference of the robot ‘s wheel to give the exact number of wheel Rotations you need. Reducing Power eg to 50 may make the robot stop more accurately.
  3. “Follow Your Robot” – whilst the robot is connected to the laptop, push it along the distance to check how many Rotations are needed to be programmed. We need to find out what units the rotations are shown in as we don’t understand them (do we need to divide by 10?). Don’t forget to programme these in afterwards!

Which method do you prefer and why? Have you used other methods with any success?

 

More Questions/ Observations

I have just finished reading the Official Manual and I have a few more observations/ comments:

  • There are lights! We could use these in our Theme or as eyes (we need eyelashes from Miss Gillan’s cupboard!)
  • Ada has 3 motors – A,B & C. Each has a Rotation sensor and a Rotation is counted as 360 degrees.
  • Our experience was that the motors don’t always seem to Rotate equally – why?!
  • If we use 2 motors to drive the wheels then we have a spare one for more exciting stuff?
  • Next Action – Coast or Brake – what does this mean? Answer ‘break’ to stop on the spot, or ‘coast’ until friction slows you down

This document was also useful lego NXT compressed (1)