Cat or Dino- Scratch 2.0 game

I saw a tweet from the @Raspberry_Pi Foundation about a game called Knifey Spoony by @Jonic one of their senior web developers did using pico-8.

Our Senior Web Developer @Jonic just released a game called Knifey Spoony.
Playing Knifey Spoony will be all you do today.
Knifey Spoony is your life now.
Life is Knifey Spoony.
Knifey Spoony.
🔪🥄 https://t.co/wTOvwkeU92

— Raspberry Pi (@Raspberry_Pi) June 18, 2018

The idea of the game is to select if the image is a spoon or a knife as quickly as you can with a timer running getting faster and faster the higher your score, so the pressure is on.

I thought this could be done with Scratch, so I fired up Scratch 2.0 and had a go.

Here is the result.  It uses only built in graphics making it easy for anyone to replicate and extend.

It is done with Scratch 2.0 but there is nothing special so it should work with Scratch 1.4 on the Raspberry Pi as well.

https://scratch.mit.edu/projects/229582133

Making Games with Scratch and Sense Hat on Raspberry Pi

I'm a big fan of the Raspberry Pi Sense Hat and Scratch for doing interesting things and learning to code.
Previously I made a Sense Hat Cave Game using Python where you tilt the Sense Hat to move around as well as a Crane controller programmed in Scratch.
This time the goal was to create game that uses the Sense Hat as the display while programmed in Scratch.  The best of both world.  The goal for me was to lean to control the pixels a bit better in Scratch.

The result is Collect the Dots a simple game where you're a blue dot collecting red dots.  It's kind of like snake without the tail.

You control your dot using either the small joystick on the Sense Hat or use the keyboard on the computer.  Press Down to start the game.  You'll see in the video it tells you this on the Sense Hat, but if no Sense hat is attached and you're running on screen there is no prompt.

As can be seen in the video the on screen display mirrors on the Sense Hat dots, so either can be used.
Strangely even though the screen display is bigger I found it easier to play if I only looked at the Sense Hat display.
The game can also be played without the Sense Hat. Uploaded to Scratch website https://scratch.mit.edu/projects/144708660/

Embedded from the Scratch Website



You can download the code from GitHub

TIP: As the wonderful Cat Lamin points out in her blog post about using doing an animation on the Sense Hat using Scratch you have to run the code once to enable the sensors and capability of the Sense Hat.  So, the first time you run the program on a Raspberry Pi with a Sense Hat it may not work correctly.  Just stop it and start again and all will be perfect

A thought for an enhancement would be to control your dot by tilting the Sense Hat rather than using the joystick or keys.

Scratch 2.0 using Chromium on Raspberry Pi 3

Playing with Scratch and thought now that Chromium is the default browser in Raspbian Pixel whether the web based Scratch would work.

So, I went to http://scratch.mit.edu and picked a project to load. Up came the usual jigsaw piece saying a plug in was missing.  Right clicked to enable the plug in and nothing happened.  Oh, well nothing has changed.  We still have NuScratch installed on the Pi.

Before shutting down I did an update/upgrade, just to keep the machine up to date.
A whole bunch of updates for LibreOffice and NuScratch were downloaded as well as an update to Chromium.  Nothing looked too interested.

Then a strange thing happened.  Half way through the upgrade a screen appears asking me to confirm installing the Flash plugin.  I accepted and let the upgrade take it's course.

Intrigued by this I went back to the Scratch website and selected the project again.
Again, the jigsaw piece appeared.
Again, I selected to enable the plugin.
Except this time the outcome was different.  The panel went white and the familiar Scratch loading bar appeared.  It was working and working well.

See the video below.

Mike Horne did a post on his website  this and Simon Long who does Raspbian and specifically Pixel 

Looks like Chromium had an update on the 11th and by chance I did an update to my machine soon after the release.  From Simon's post this needs ARMv7 so  only works on Raspberry Pi 2 and 3. Not an option for older Raspberry Pi or the PiZero.

Toy crane controlled from Raspberry Pi Zero with SenseHat using Scratch

Since the micro:bit was launched one of the demos that I kept seeing was the toy crane controlled using the motion sensing in the micro:bit.  The kids loved it and was very interactive.

Since the SenseHat on the Raspberry Pi has the motion sensors built in I thought this would a good project for a Raspberry Jam.

So, off I went to Home Bargains and bought a crane. From the picture, definitely the right age for me.  This crane is normally controlled using two levers on the hand controller. It can rotate and raise/lower the bucket.

Didn't come with the hard hat

First order of business was to figure out the wiring and cut the cable as the final build would be battery powered to work the same as the micro:bit version.

Cut the red wire

From above the wiring is:

VCC - Red wire
GND - Brown wire (not black)

Rotate motor 
Orange and Yellow

Crane lift motor
Blue and Green.

For turning and crane the direction it goes depends on how you wire it up and how your code works so some adjusting may be needed later.

To make sure I had this right I tested by touching Red to Orange and Brown to Yellow. Crane rotated one way. Swapped wires around and crane rotated the other way.
Red to Blue and Brown to Green, Bucket went down. Swapped wires around and bucket went up.

Wiring confirmed and tested.

As the Raspberry Pi isn't designed to control motors directly I needed a small motor controller.
The L9110s looked perfect for the job. Smaller than the L298N that I usually use so would be easier to accommodate in the final box.

L9110s motor controller

The 2 terminal blocks on the left in the image are for the motors.
On the right are the control pins and power.
Top 2 connections are control for Motor A
Bottom 2 connections are control for Motor B
Then in the middle are VCC and GND

NOTE: A really important thing is to make sure when using multiple boards that all the GND lines are tied together so that all the voltages have the same base reference.  Otherwise strange things can happen.

I wired up the motors. Turning uses GPIO 5 and GPIO 6 on the Raspberry Pi and Motor B on the L9110s while lifting uses GPIO 27 and GPIO 17 and Motor A.

Again did some simple code to see if it would work from Scratch. Initially manually moving with the keyboard.  It worked great and I brought it along to the Egham Jam in April 2016.  As the organiser of the Jam I was a bit delinquent in taking pictures so the only one I have is of the crane, bottom left in the booth of the car before I went to the event. I promise the kids loved it and it was a massive hit, really. Actually, I had a different project called ZeroBall that was finished so it took most of my time.

Bottom leftis the crane

There were two technical reason I didn't have it all set up with motion sensing and coded in Scratch for the Jam.

1. The SenseHat covers all the GPIO pins meaning I couldn't get at the pins to attach the wires for the motor controller.  So, I could get the readings from the SenseHat but couldn't control the motors.
2. The Scratch at the time had a problem whereby it didn't support AddOn board. 

The first problem was solved with Stacking Headers and great tutorial from Keith's Pi Tutorials even has a video.
Also, a great reference site for Raspberry Pi board pin usage is pinout.xyz.  They have loads of boards listed and this is where I got the details for the pins used on the SenseHat

Stackable Headers. Note the high tech blutac for holding it all in the tub

The second problem of Scratch not working at all with AddOn boards was reported and fixed in the May 2016 Raspbian update.

With the purchase of Stackable Headers from The Pi Hut and a freshly imaged SD card both of these technical problems were overcome and the way forward was sorted for the SenseHat to be used to control the crane.

Since I wanted it to be battery powered the Raspberry Pi Zero was the obvious choice as it is low power. Only thing is Scratch is a GUI program and so I needed a desktop environment to run it (If you can run Scratch code without a GUI I'd love to know, but I suspect it kind of defeats the purpose of a drag and drop interface if you run it from the command line)

To overcome this I used a USB wifi dongle to connect over the network to the PiZero and then on a laptop used RealVNC to get a desktop. Since this was going to be shown at the first Wimbledon Raspberry Jam I didn't know if I would have a wifi network to connect to so I brought my own in the shape of a VoCore. A one inch cubed wireless router running openWRT.  I backed this as a crowdfunding thing a while back and all I've used it for it to create a local wifi hotspot.  At the Jams I can even power it from a powered Raspberry Pi USB port.

Side Notes:
I think the number is the manufacturing order of the original batch and I've never seen one with a number lower than 26.
The VoCore is only the top layer. The rest is an add-on that gives you USB, Ethernet, microUSB power socket and a microSD slot.  IT also has it's own GPIO pins so can be used for embedded projects.

Vocore. Basically, the guts of a wifi router

Obviously, as this was going to be standalone it had to be battery powered. I'd been picking up these 18650 Lithium Ion batteries in Poundworld and thought 4 of these in a case would make a decent power supply for the day.  No idea why when I cracked them open one was pink.  The battery case was from eBay and it all snapped together really easily.
The case has 2 USB ports for power so could power the Raspberry Pi and the VoCore at the same time.

Batteries in their original cases

Batteries in their new case

I mentioned above that all the Grounds need to be tied together.  In this instance I have 3 circuits that need to all have the same GND. Crane, L9110s and Raspberry Pi Zero (The SenseHat is take care of through the Pi Zero)
I tied the Crane GND (Brown wire directly to Pin 39 on the Raspberry Pi, then the GND pin on the L9110s was tied to Pin 6 on the Raspberry Pi.  In this way all 3 had a common GND.

It's good to be aware that in a circuit all GND can usually be treated as the same point. Especially for such low power and low frequency signals.  If this was a high power high frequency circuit then the trace length between the different GND points could case harmonics.  I cannot think of a project using the Pi that I would do where the length of the trace between GND pins would be a problem

So, now I have power, local network, a way to run Scratch so people can see the code and all the bits wired up. Last of all was the actual Scratch code.

From the image you'll see the code isn't very complex.  The main thing I'd to figure out was which one of the sensors I needed to read. It's the Accelerometer.
I believe the range is -4095 to + 4095 on each axis.
When the program is run a base "flat' reading for Lifter and Turning is taken so any movement in the sensor doesn't carry from one person to the next.  This is what the middle block of code does.
The block of code on the right is there if it all goes wrong and I can just press [space] to turn off the motors.

Th middle block is where the magic happens.  It checks if Accelerometer X is 1000 less or 1000 more than the flat reading for Lifter and/or Turning and then activates the appropriate motor to either turn the crane or raise/lower the bucket.

Not shown below is a second costume for the crane that just says "Put Pi on a flat surface" at the start of the calibration.

If you're not up for trying to copy the code from the image you can download the Scratch code from GitHub.

To make it hand held I stuffed all the bits in to a plastic Chinese takeaway box.  You can see the L9110s on the left, wifi dongle on a short microUSD to USB cable and the SenseHat with the Stackable Headers so the wires for the motor controller can could be added.

Finally, here is a boy totally engrossed in playing with the crane at the Wimbledon Jam.  It all ended really well.

Hours of fun transporting monkey from one place to another

9th Egham Jam – Show and Tell Competition – Prizes donated by 4tronixs

I think we might be coming to the end of the Prize announcements.
So, last but not least are the Prizes donated by 4tronixs.

Robot lovers Prizes from 4tronixs

These prizes are especially situated to the robots lovers.

Each Prize includes:

The PlayHat includes a 3x3 full colour neopixel LED matrix, 4 big buttons and a buzzer.
Great for programming with the Raspberry Pi. This is just begging out for a game of Simon to be created.

PiRoCon and iBoost64 This board is great. Te PiRoCon  plugs right on top of the Raspberry P and gives you all the additional electronics needs to drive motors.
Motors are fun things. When they start they draw a lot of  power (think of train pulling out of the station. It needs far more power to get going then it does to keep itself moving.  Same thing for motors).  This mean if you want to drive motors you need extra circuitry to do it safely without damaging your Raspberry Pi.  The PiRoCon is one of the best solutions for this for the Raspberry Pi.

In addition to motors drawing a lot of power when they start and stop they can also affect the voltage and current of electronics drawing from the same power supply.  This can cause difficulties in getting good readings or accurate control.  This is where the iBoost64 comes in.  It cleans up the signals and makes them good without affecting the rest of the circuit.  Ideal for robots where there can be a lot of stopping and starting of motors as well as reading of external sensors for line following or object avoidance.

With the combination of the PiRoCon and iBoost64 you have the electronics to get that robot built.
If working in Scratch the current ScratchGPIO library from Simon Walters supports the PiRoCon.

If you have robots you will need power.  The final 2 boards are a 1 way and 4 way charger board for Li-Po batteries.  These are great batteries for robotic as they store lots of energy and give out a consistent voltage.  Cheap batteries have a power curve that means they very quickly drop from the maximum voltage which can cause lots of problems with motors.  Li-Po batteries are the ones used in high quality remote control cars.
Unfortunately you can't just plug a Li-Po battery into your normal battery charger due to the way they work so custom chargers are usually provided or need to be purchased with the battery.  These great little boards mean you can use a standard 5V microUSB power supply to charge the batteries.  This is the same type of power supply used for the Raspberry Pi, meaning if you are building a Raspberry Pi based robot you will already have the correct power supply.
There are 2 different boards included.  A 1 way, so it can charge 1 battery and a 4 way which can change 4 batteries at the same time.  Giving you more than enough power for your laser guided, GPS tracking, missile shooting, web cam streaming, grabber, digger, flame thrower robot. Or maybe just a line following robot.

From the picture you can see they also provided some pens.

Thank you 4tronixs for the prizes.

Created a game in Scratch

I came across some videos of Jeff Minter who created some amazingly original games in the 8 bit era and is still going strong developing new games today and it got me thinking of one of his stranger games that I remember playing on the Commodore VIC-20.
Meta Galactic Llama Battle at the Edge of Time.  Here's a video of it on the Commodore 64. I can't remember if I had it for the C64 as well, but definitely played it on the VIC-20

As with most of Jeff Minters games it kind of takes a slightly different approach.

You're a Llama at the bottom of the screen and you can move left and right.  You can exit one side of the screen and come in the other side as well.

You shoot lasers out of your mouth at 45 degrees and you have to shoot the spiders falling from the top of the screen.

If a spider reaches the ground it starts to crawl towards you making evasive action essential. 

All very interesting so far.  To add to the complexity and the control you can also raise and lower a ceiling for your laser to bounce off of to assist in shooting the spiders.

 I had great fun with this game all those years ago and so wanted to see if I could re-create something similar using Scratch.

After some fumbling I put created a little game inspired by the Llamas.

Below is the game and here is a Link to project on Scratch website if you want a peek inside. https://scratch.mit.edu/projects/61239650/

It's been fun developing a game in Scratch. I'm most definitely not an expert and I expect there are a lot of refinements that could be done to the code to improve the game but it plays similar to the original.  I hope you enjoy it.

7th Egham Raspberry Jam - 26th April 2015

What a great Sunday afternoon of Raspberry Pi activity.

40+ people turned up on the day with an ever greater proportion of parents with their kids with a real buzz on the day.

The most popular tables were the ones where a boy and girl were showing other kids how to program in Scratch.  I had a lovely experience at the end of the event where a father and his daughter came of to say they were leaving and the daughter was beaming as she had just written her first program in Scratch.  It was amazing to see the excitement on her face and the please she was experiencing from leaning a new skill.

For those interested in the latest in desktop environments +Martin Wimpress was there showing how fantastic Ubuntu Mate run on the Raspberry Pi 2 with desktop effects enabled. We had a great chat about RPi.GPIO support and what it would take to have it baked into the next build.
Martin also solved one of my questions. When navigating menus in Mate on the Pi2 sometimes they would stick and not respond.  I thought this was an I/O issue but it looks like it is down to OpenOffice have massive icons SVGs so on first opening a menu the Raspberry Pi has to render the icons for display. This happens once when you go to the menu for the first time. For return visits the icons are already renders so the menu is nice and fast.
I'm trying to decide if I will uninstall OpenOffice as Abiword and Gnumeric give me everything I need and then for graphics I use GIMP and Inkscape.
Martin had a build of Ubuntu Mate that used F2FS (http://en.wikipedia.org/wiki/F2FS) This is a file system specifically designed for flash memory and is suppose to improve the life of SD cards as well as improve performance.  I haven't had a chance to test yet but another win for optimisation.

As a side note GIMP and Inkscape are definitely usable on the Pi2.  I have previously used both on hardware of similar performance for commercial website development.  It's not going to match your i5/i7 with 16GB RAM and the latest graphics card, but it is definitely usable.

A second side note not from the Jam. I had my Ubuntu Mate Pi2 set up at home and needed to print.
It found my wifi network printer and installed all the correct drivers without me having to do anything special.  I love that Graphics acceleration just work, wifi (with the right dongle) just works and printing just works. There are the 3 points that I usually have concerns about on Linux and with the Raspberry Pi they just work.

Back to the Jam details.
Among the many items on display were:

Music playing Octopus (see flickr link at the bottom for pictures)
Portable games console,
Robot arm controlled by Scratch,
Crumble board (http://redfernelectronics.co.uk/crumble/) A great little interface board programmed using an block based interface like scratch.
Minecraft fun
Robot with robotic arm and webcam all controlled using PWM to vary speed from an Android table.
Sonic Pi coding +Sonic Pi
Scratch Development
CNC machine controlled by Raspberry Pi by +Stephen Cornes
EEG Brainwave reading using Mindflex, Arduino and Raspberry Pi
7 Segment of Pi board for development
Pitrol - build it yourself controller for the Raspberry Pi

At the end of the event I got the TwitterCam running and it did take pictures and tweeted them
The pictures can be see at the @EghamJam feed

Here is a link to some pictures from the event if you want to get a flavour for what happens at the Egham Jam.

https://www.flickr.com/photos/tictactoepony/sets/72157649918333124/

What a great day and thank you to everyone who came and brought their projects and enthusiasm to share.


We also had some Motorola LapDock troubleshooting going on as well.  These things turn your Raspberry Pi into a laptop

EEG Brainwave reader with Ubuntu Mate Visualisation

Looking forward to the next Egham Jam.

List of online resources to assist in learning to code

The final session of the robot club at my kids school was Easter break and I promised them a handout detailing resources that are free they can use to continue to learn to code.  The kids were aged 10-12 and most were very new to coding so wanted to give a range of resources.  
They've spend the last term building small robots with an Arduino as the main controller so included Arduino as well as general programming resources.

As per the sheet a great combination for new people starting out if they don't have any hardware is the Earthshine Electronics guide and the AtuoDesk 123D Circuits online electronics and Arduino emulator.  The guide gives 14 projects of varying degrees of complexity from an electronics and programming standpoint and the AutoDesk 123D Circuits gives you a free resource to do your coding. The electronics pieces is done on a breadboard and is very visual. Reminds me of Fritzing.

https://drive.google.com/file/d/0B23BvTk93HRYSmZzU2RnclhhRlU/view?usp=sharing

If you'd prefer not to download the handout here is the list of links

Websites

Scratch - https://scratch.mit.edu/

Code.org - http://code.org/learn

BBC Dr. Who programming game - http://www.bbc.co.uk/cbbc/games/doctor-who-game

Codecademy - http://www.codecademy.com/

AutoDesk 123D - http://www.123dapp.com/circuits

Books and Reading Material

Invent with Python - https://inventwithpython.com/

Earthshine Electronics – Arduino Starter Kit Manual - http://thearduinoguy.org/?page_id=100

YouTube Channels

Jeremy Blum, Tutorial Series for Arduino - http://bit.ly/1xrxqvr

Kevin Durrah - https://www.youtube.com/user/kdarrah1234/featured

The New Boston - https://www.youtube.com/user/thenewboston/featured

Egham Raspberry Jam - 25th of January

What a day. More than double the attendees. More than double the stands, more teachers and kids attending.  More fun and learning than ever before.

When the Egham Jam was announced back in December I thought we would do better than the last Jam (46 registrations) but was blown away by the response.
Maybe a lot of new Raspberry Pis were sold at Christmas.
We were not only 'SOLD OUT' but also had more people who wanted to attend as well as people who register who advised me they couldn't make it so their tickets were released.

In the end 90 attended, more than double the October event and a record for the Egham Jam.

I was also really delighted the number of educators who attended looking for ways to integrate the Raspberry Pi into their schools Computing work.

There were at least 12 show and tell standard, some of them had multiple displays making for a very interesting day.  Also, very delighted that on a number of stands children were leading the show and tells. Giving great demonstrations on what they have build.

I tried to meet everybody who attended as possible and got the chance to connect teachers and people with specific needs with others who I know from previous Jams demoed a similar project.

Below are some pictures from the event.  Lots of fun.  Roll on the next Egham Raspberry Jam.

Surrey & Hampshire Hackspace were out in force

Scrolling messages

Pirates and MiWars winner

Raspberry Pi Development solution in a box

Robots are go.  Controlled over Wifi

Kodi set up being demoed by a young engineer

PiTrol - build it yourself controller

Remote arm controlled in Python

RISCOS on an HDMIPi

Seven Segment of Pi display

Getting the Wifi network set up to demo Airplay

Minecraft and RetroPie

Scratch 

Robot arm controlled from Scratch

Seven Segments of Pi. It's a big one.

4th Egham Raspberry Jam - 3rd November 2013

Yesterday was the 4th Egham Raspberry Jam and we had a great day with a variety of projects on show and nice range of people attending.
Everything from people learning about the Raspberry Pi so they could teach their grand children about computers and computer technology to children looking to be inspired for school projects.

I arrived about 12:00 noon to get set up and people showing started to arrive around 1:00.

We had a great mix of projects.
Leo White's Big Trak http://www.mybigideas.co.uk/RPi/BigTrak/
Now upgraded with a new metal robotic arm.

Leo also has a project that just looked like flasking LEDs on the PiGlow until I had a quick chat with Leo and found out that it was all being done in BBC BASIC using RISCOS running on the Raspberry Pi. So, if your old enough to have programmed in BBC BASIC you will be right at home.

Carl Monk brought along his DeLorean Time Machine control panel and flux capacitor as featured on the Raspberry Pi website http://www.raspberrypi.org/archives/4856

Carl also brought along his Pumpkin Game. Great fun using Pumpkins to play a Scratch based game.

Stephen Cornes brought his excellent LED clock which displayed the time in multiple formats.  This project uses the excellent Pi-Lite board which communicates with the Raspberry Pi over serial.

Alan has his bi-direction motor controller running. Even though this is a small project it is a major milestone as Alan knew nothing about Linux, programming or electronics when he came to his first Jam and now he is writing python code on a Linux computer to control a real world motor using a H-bridge.

Matt Sendorek brought along his excellent Maplin robotic arm controlled from Scratch using an intermediary Python script.  Matt has been building this to to use in his after school computer club and from his picture on his write up of the  Egham Jam it looks like it's the perfect thing to get kids interested in computing http://mattrealm.me.uk/blog/?p=41

Matt has also put together a guide to getting the robotic arm working with Scratch

http://www.mattrealm.me.uk/media/arm_doc.pdf  

Marcus Taylor-Moore brought along his robots that were used in a maze challenge and also a really small quadcopter. All very exciting and I know I want both...

https://plus.google.com/u/0/+MarcusTylerMoore/about

Nicholas Herriot had a great set up of home automation. I must admit I didn't get a change to chat much to Nick and so my knowledge of his project is very limited.

Then the amazing Neil Ford came with a show of his own. Not content with 1 display he brought 5

2 Wheel Robot controlled by Raspberry Pi. Perfect as a beginner robotic project with a build that requires no soldering and only a bit of glue.

Neil set up a station where visitors could try out Scratch. See how easy it is to use and how through some simple steps interesting and fun projects can be built.

We had some great music being composed using SonicPi. I must get some time to check this out as it really looks like a great way to introduce programming and giving immediate feedback in a fun way.

How about controlling real world objects with Python

Finally, a great Minecraft set up that was very busy during the day. With kids doing some playing and programming. 

My own little project was Halloween based with a PIR detecting motion and then flashing LEDS inside a couple of clear/greenish skulls and a 'Scream' mask and at the same time played a creepy sound. The sound was so convincing that my daughter didn't like me playing it at home.  All programmed up in Python and using Pygame to play the audio. I did up a PDF Guide with the build instructions and also the Python code. Special call out for Raspberry Pi Spy for his guide and code I used for the PIR motion sensor.  I was just looking for the details on the PIR as I bought it on ebay and so received no instructions. Not only did Raspberry Pi Spy provide details on the PIR he also provided code that works..

I also brought along the Surrey & Hampshire Hackspace 2 pager cheat sheet with details on programs to install on the Raspberry Pi, Controlling an LED, building a Sphere in Minecraft and other useful information on one page and the FOSSWire Linux Cheat Sheet which is a great reference for the often need Linux commands that somebody starting out may not have experience with.

The Hackspace is based in Farnborough and is a great place to meet like minded people who are interested in Raspberry Pi, Arduino, Linux, 3D Printing, Online security as many other fun activities.

I hope those who came had a great time and were inspired to try something new with their Raspberry Pi. It's an amazing little bit of kit that can be used in many different ways (as can be seen from the projects on show)

Here's looking forward to the next Egham Raspberry Jam.

Also, if you're into seeing what's going on with the Raspberry Pi and have a focus on Education the the Raspberry Jamboree on the 27th-28th February 2014. Some great presentations and workshops are already announced and more will be announced closer to the time. I plan to be there on the 28th at least. Maybe stay over for the party.  

Raspberry Pi Model A - Scratch performance with 2013-05-25 Raspbian image

With the new Raspbian 2013-05-25 image Scratch is suppose to be faster due to the work on the Pixman library.
So, I thought I would do a comparison between the new image and the 2012-07-15 image.
With the expectation that Scratch will mainly be used in schools and that these may be kitted out with Model As I did the testing on a Model A, so limited to 256MB of RAM

Video Below:

I download the images and flashed them fresh to 8GB SD cards - same make and model.
Then on boot up expanded the partition.
No updates were done and only a wireless keyboard/mouse USB dongle was plugged into the single USB port.

The Scratch program has 3 sprites + Stop Sprite. Each main sprite has 2 costumes and they move around the screen bouncing off the edge.
1 Sprite (Felix) also increments a global variable by 1 for each step.
This whole thing is repeated 500 times, giving a long enough time for the task to get a fair comparison. Shorter and the difference in speed would have been harder to measure. Longer and I would have fallen asleep.


Raspbian 2012-07-15 Image
Login was rejected a few times before I was allowed it. This is with the default username/password and using the same keyboard as for the 2013-05-25 image so it looks like some USB based issues were resolved since the 2012-07-15 image was released.
Scratch felt sluggish in loading and resizing the program to full screen
To keep it consistent I ran the program full screen. On the 2012-07-15 image full screen did not stretch but just put a 480 x 360 window in the middle of the screen
Test ran in 1m 22s


Raspbian 2013-05-25 Image
Login worked first time every time.
Scratch felt responsive in loading and resizing the program to full screen
Full Screen stretched to the resolution of the screen, so was true full screen experience.
You will see the updating of the Variable is not real time. It looks like variable updates on screen do not happen every time the variable is changed.
Test ran in 0m 51s 
37% faster than the 2012-07-15
An amazing increase in performance purely based on a software update

Raspbian 2013-05-25 Image Turbo Mode (1GHz)
I used raspi-conf to set the the Raspberry Pi to Turbo Mode to see what the maximum performance is.
Login worked first time every time.
Scratch felt really responsive in loading and resizing the program to full screen
Full Screen stretched to the resolution of the screen, so was true full screen experience.

You will see the updating of the Variable is not real time. It looks like variable updates on screen do not happen every time the variable is changed.

Test ran in 0m 33s 
60% faster than the 2012-07-15 (non-Turbo)
35% faster than 2013-05-25 (non-Turbo)

Compared to stock 2012-07-15 image the new 2013-05-25 image with Turbo mode set is nearly 3 times faster in Scratch.
All without a hardware upgrade and with user changeable settings.

The only limitation appears to be the speed at which variable are updated on the screen. The variables are updated in the background it is purely the screen update that is slow.

For most thing I'd expect the variable issue will not be a problem so a fantastic result.

Scratch is now definitely usable on the Raspberry Pi.