Pi-Stop – Updates, new materials and a new product!

The Pi-Stop and the Pi-Stop Stands are now available from the 4Tronix website.

The Pi-Stop

Pi-Stop Support for “Plus Models”

The introduction of the model B+  (see my previous post “Fresh Pi” for more details) conveniently adds two additional locations for the Pi-Stop, which we will call Location A+ and Location B+.

New Pi-Stop “Plus Model” locations

Pi-Stop “Original Model” locations
You will notice that Locations A to D remain totally unaffected, so you can continue to use the same guides and examples on any model or variant of the Raspberry Pi.

New – RGB-LED and DPad “Plus Model” Support

I’ve now updated the user manuals and guides for the RGB-LED kit and the DPad Kit so “Plus Model” users can easily connect and use them. The kits are fully compatible with ALL variants of the Raspberry Pi.

Pi-Stop GitHub Updates

I’ve updated the Pi-Stop Git Hub workshop files to include details for both models:


In the development branch I’ve started to experiment with a special method of customising the markdown pages, this will allow me (and users) to create easy to adjust workshops and smooth out the process of publishing the workshops both here (or if anyone else wishes to publish them) and on GitHub.

New Guides

I’ve been busy thinking up some great new ideas for some more workshop materials, including some with Pirate and Secret Agent themes!

Of course I would welcome any additional feedback on the current materials too. If you use them let me know how you get on!

And finally…

We also have a little surprise from the 4tronix foundry…

4Tronix PiStop Road Crossing preview!

4Tronix PiStop Road Crossing preview!

Looking forward to writing some guides and tutorials (and games!) for it.

Fresh Pi

Posted: September 7, 2014 in General

Fresh Pi

The summer also saw a new iteration (or “evolution” as the foundation calls it) of the Raspberry Pi.  The Raspberry Pi Model B+ is an incremental improvement to the older Model B (a Model A+ version is due later in the year).

The Register provide an excellent review explaining the new changes.

Improvements include:

  • USB ports increased from 2 to 4 (thanks to new version of the combined LAN/USB hub chip)
  • Replacement of the 3V3 linear power supply with a switch-mode supply (around 30% power saving) – users of my 5V Switch-mode PSU will be well aware of the advantages!
  • Rewiring of power links (so USB hubs will no longer back power the Raspberry Pi)
  • The 26 pin P1 header has been extended to 40 pins (the first 26 pins are identical to the original version but add-ons which fit directly on to the GPIO header may have problems fitting) – ALL of my add-ons will work exactly the same with the Model B+, simply wire them to the top 26 pins.
  • Looking closely at the GPIO pin functions there is also an additional hardware PWM (which is extremely useful for directly driving servos).  By having two hardware PWMs it is dead easy to add a servo controlled tilt AND pan fixture for the Pi-Camera!
Dual servo Tilt and Pan camera/sensor mount - typically this would need two PWM outputs to control

Dual servo Tilt and Pan camera/sensor mount – typically this would need two PWM outputs to control (now available on the Model B +)

  • The composite video connector has now been combined into the headphone audio socket, it will function as a standard audio socket but with a suitable 3.5mm audio-video cable you can continue to use the composite video out as before.
  • External connectors moved to two sides – which means you can mount it inside something a lot easier (fit it into a corner and all the ports will be on an edge).  Although it does mean you will need a new type of case (which is fine since you probably already have a RPi to fill your old case).
  • The full size plastic SD-Card slot has been replaced with a metal micro SD-Card slot.  Since the SD-Card slot has been a particular weakness of the original Raspberry Pi this is great news.  If your collect of SD-Cards are full-size ones you will have to get hold of some new micro SD-Cards – thankfully the price of an 8Gb micro SD-Card has dropped since the Raspberry Pi was first released so this shouldn’t be a big issue.

Image from raspi.tv (I have to borrow the image since I’m yet to get a Model B+ of my own)

There is also a great detailed look at the NEW Model B+ at RaspTV : Raspberry Pi Model B+ Launched Today

I’ll be updating the guides and lessons to ensure that Model B+ users will be 100% clear how to connect the add-ons.

UPDATE: I’ve now updated the user manuals and guides for the RGB-LED kit and the DPad Kit so “Plus Model” users can easily connect and use them.  They are fully compatible with ALL variants of the Raspberry Pi.

Old Hat? New H.A.T.

One particularly interesting feature is HAT (Hardware Attached on Top) which will allow Model+ add-ons to identify themselves to the Raspberry Pi allowing automatic configuration of any drivers or programs when different hardware is connected.  HAT is basically a I2C interface (via Pins 27/28) which on a HAT board will connect to a I2C EEPROM (which will contain vendor info, GPIO map and valid device tree information).

Note that HAT is not compulsory and would make little sense on smaller less complicated boards, however it should take the pain out of more complex add-ons such as screens and digital sound-cards for example.  Potentially you could create an entire system which through HAT will be configured to function as soon as it is connected.

Gert’s great VGA surprise!

Revealed only yesterday, Gert-Van-Loo (a truly excellent guy without which the Raspberry Pi may have not made it without his hardware skills), a new add-on for the new Model + Raspberry Pi which provides VGA output.

Through some clever electronics and cunning use of the additional GPIO added on the Model B+ (so this VGA add-on will NOT work for non “plus” models), Gert has been able to provide native VGA output (i.e. full GPU output, no CPU loading, 1080p/60 and dual screen with HDMI).

The best part is his has said it will be open-sourced and the components required are incredibly basic so it should be nice and cheap too!  A good reason to keep hold of those VGA only monitors and LCD screens, this should help out a large number of schools.

The not so good news though is it uses all but 4 of the GPIO pins…so we shall have to see what hardware we can support while using the VGA output.  You can be sure that we will find a way to still use hardware with it, one way or another!

More details from RaspTV : VGA for Pi Debuts at CamJam, alongside HDMIPi production model No. 1

Welcoming in the NEW!

Posted: September 5, 2014 in General

Well the summer has come and gone very quickly and September has flipped over on the calendar far too quickly.

Back to School

With September we welcome in the academic new year, millions of children starting in new schools, new classes and with a brand new curriculum.  2014 brings in the latest incarnation of the “Computing” curriculum which promises to replace the outdated ICT (Information and Communications Technology – aka how to use MS Office) with a new focus on programming.


Image thanks to www.freedigitalphotos.net (user stockimages)

Image thanks to http://www.freedigitalphotos.net (user stockimages)

A good explanation of the new curriculum can be found on the Guardian website.

This long overdue change is one which has been championed by the Raspberry Pi foundation which have not only provided a home computing platform for children (and adults) but have spent a huge amount of resources adapting its use for the classroom.

They have also been busy providing expert training at their very own Pi-Academy.  The Pi-Academy is a 100% free CPD (continuous professional development) available for teachers in the UK – and being FREE means not only do teachers get top quality training but it leaves more funds available to actually buy equipment to make use of the training.  The next session starts at of the end of September, swiftly followed by another in October!

New resources for the Raspberry Pi in school

Be sure to check out the new Teacher’s Guide to using Raspberry Pi in the classroom created by the foundation (although I feel that the MagPi magazine should be highlighted as a huge resource of information for schools, teachers and pupils).

Also don’t forget the Pi-Stop github which has  ready-to-go workshop materials for use with the Pi-Stop (or with some adjustments, any other traffic light type add-on or hardware – such as my Breadboard  & Components Kit (Chapter 6)).


Create your own traffic lights, just waiting to be programmed!

Create your own traffic lights, just waiting to be programmed! – using the PiHw breadboard and components kit 

There are two particularly awesome projects which if you are running a school, class-room, club or even a few Raspberry Pi at home should be particularly useful to you…

1. Raspi-LTSP – Raspberry Pi Linux Terminal Server Project

This is a full set-up suitable for running a large number of Raspberry Pi computers, complete with centralised user management, a single shared operating system and management of study tasks.

Ideal for a school set-up as each Raspberry Pi only requires a minimal boot SD-Card (which doesn’t even need to stay inserted in the Raspberry Pi once connected – so only a few cards could start a whole classroom).  The Raspberry Pi will connect to the central server and load a copy of the master image (a typical Raspbian install) via the network.  The pupil will login with their own personal details and have access to their own profile (no matter which Raspberry Pi or SD-Card they were using previously).

Compare this to a class-room of standalone Raspberry Pi computers, each with their own SD-Cards which (if not painstakingly re-imaged and set-up each lesson) soon become a mess to handle (and that is without needing to consider how you keep pupil data safe and accessible from lesson to lesson).

As much as I love the idea behind this concept it is probably overkill for my uses in workshops (for now – although it would be an excellent workshop in itself) but I would love to hear how others are getting on using it or are interested in using it.

2. Noobs Config

 This a fantastically useful variant of the official NOOBS set-up, it just needs a single script replaced from the standard NOOBS scripts to enable it.  From then on, you can take any of the standard images supplied with NOOBS and use the Noobs Config method to insert files/configurations automatically as part of the imaging process.

To put it simply…this is VERY powerful and incredibly useful!

NoobsConfig by procount

NoobsConfig by procount

I’ve experimented extensively with this set-up and produced excellent results, from a single image I can select from multiple custom flavours which can automatically install all my preferred programs, settings (including WiFi settings, menus, start-up scripts) or even automatically running demonstrations on power-up. I’ve even used it to provide workshop attendees with images which are pre-configured with my workshop materials and all the required installations ready completed.

Noobs config has the advantage over the standard flavours methods supported by NOOBS as you don’t need to keep repackaging all the files.  Noobs config allows you to construct multiple set-ups directly from the files you place on the SD-Card (allowing common settings to be shared between set-ups seamlessly).

One particularly handy set-up allowed scripts to dropped onto the SD-Card from a Windows or Mac computer, and automatically run when the Raspberry Pi is powered up.  Combined with a basic hardware shutdown button (which can also be automatically added to the config), this would allow simple Raspberry Pi hardware programming without the need for a screen!

For the home user with one or more Raspberry Pi computers in the house, it makes it very easy to set-up and reinstall SD-Cards without needing to go through the painful manual configuration process.  You can have a brand new clean image built in a matter of minutes, which is tailored completely for your needs.  Once you get in the habit of adding anything useful to your configuration, you’ll soon wonder how you managed before!

I’m going to continue experimenting with these various set-ups and share a few how-to guides on how to do it yourself.


I’m pleased to announce the Pi-Stop is now available to pre-order from the 4Tronix.co.uk shop.


The Pi-Stop


Take a look at the product page on the 4Tronix site for more details, or on my site, or take a look at the resources available via GitHub (contains a range of workshop materials and resources available to use or adapt for your own needs).

I look forward to sharing this exciting new add-on with everyone!

First off, a big thank you to everyone who came to the workshop, I hope everyone had a wonderful time.

The whole Digimakers event was absolutely amazing, had a really great time, huge thank you to all involved (organisers, people running workshops/showing things off, and of course the people who came along!

Unfortunately, I didn’t take many photos so I shall have to let other’s document all the wonderful things that were happening.  However, I did promise I would post up the materials for the workshop, and this is the purpose of this post!


It was great to see the response to the Pi-Stop, the workshop material and to meet so many great people.


My focus now is to get all the workshop materials loaded on to the website, the PDF files are below.

As mentioned before we had a REDYELLOWGREEN theme for the workshop material.




The files are stored on a new GitHub repository:


  1. REDSetup: Scratch GPIO (workshop version) [PDF] – Explains how to setup Scratch GPIO
  2. YELLOWExplore and Challenge Scratch GPIO: Pi-Stop First Steps [PDF] – Introduces how to use Scratch and using Scratch GPIO. If you are already familiar with Scratch you can skip this.
  3. GREENExplore and Challenge Scratch GPIO: Pi-Stop Traffic Sequence [PDF] – Create your own traffic light sequence and learn how to use Scratch GPIO with the Pi-Stop.
  4. GREENExplore and Challenge Scratch GPIO: Pi-Stop Reaction Game [PDF] – How fast are your reflexes? Test your reaction time with the Pi-Stop Reaction game.
  5. GREEN: Explore and Challenge Scratch GPIO: Pi-Stop Simon Memory Game [PDF] – Challenge your memory and get the highest score!

The worksheet is also available here:  Workshop Worksheet [PDF]

Generally once we got through the RED stage, everyone flew through the rest of the material and there was lots of additional programs being written, new experiments and lots of great stuff being done!


I will be posting up more information about the Pi-Stop very soon (it deserves a proper introduction), including all the source files used for the workshop (I want the materials to be open and available so it is easy for people to modify and adjust them to suit their own needs and requirements).  For example, it would take very little to adapt the material to work for any traffic light/3 LED type board/kit.

In fact, I have some cunning ideas regarding that which may work nicely for making the material even easier to adapt (shall have to wait and see if it works).

As soon as I have more information regarding availability of the Pi-Stop I shall let everyone know.

If you are interested in classroom packs, or would like additional information then feel free to contact me:



Finally, many thanks for a most excellent day!

Tim Cox.

I will be attending the Digimakers event Saturday and running a workshop.

The workshop will be using an exciting new prototype board called PiStop!


The attendees will be the first to use the new board and I will be keen to see what everyone thinks about it!

I will add more details on the board soon (since I still have workshop material to prepare) – I have lots of juicy details on how the board works, the different ways it can be used and the whole idea behind it.

The workshop will be using Simon Walters (@cymplecy) excellent Scratch GPIO:


 Getting Setup!

For those who are attending, here is a link to the setup PDF, which will detail the setup steps for the workshop.

Setup:Scratch GPIO (PDF)

There isn’t much to setup, you will just need a standard Raspbian image and a single file (available from here: http://goo.gl/Pthh62).

Obviously if you are able to download it onto your Raspberry Pi ready, then it will save time and hassle in the actual workshop, you can do this with the following command:

sudo wget http://goo.gl/Pthh62 -O install_scratchgpio5.sh


Don’t panic if you are not sure what you need to do yet, there will be help at hand on the day and plenty more information available if you need it.


Other Equipment…

You will need your Raspberry Pi, Power Supply and SD-Card.  Plus a screen/keyboard/mouse (some will be available) or laptop (see below):

There will only be a limited number of screens/keyboards/mice available, so if you have a laptop (it will need built-in wired network socket, most do) please bring it along and I will be able to show how to directly connect to your Raspberry Pi.

Again, if you can try this before the workshop then you will be good to go straight away.

Details here: https://pihw.wordpress.com/guides/direct-network-connection/

Connect and use your Raspberry Pi with just a Network Cable, SDCard and Power!

Connect and use your Raspberry Pi with just a Network Cable, SDCard and Power!

You will also need to install Putty and Xming on your laptop (to allow you to connect and display Raspberry Pi desktop programs on your screen):

Download and run http://sourceforge.net/projects/xming/ from the Xming site.

NOTE: If you have VNC setup or know how to find your Raspberry Pi on a network, then you can use that if you prefer.



The workshop plan

Going with the RED, YELLOW, GREEN theme the workshop material is split into three stages: setup, learning and experimenting:


  1. RED: Setup: Scratch GPIO (workshop version) – Explains how to setup Scratch GPIO
  2. YELLOW: Explore and Challenge Scratch GPIO: Pi-Stop First Steps – Introduces how to use Scratch and using Scratch GPIO. If you are already familiar with Scratch you can skip this.
  3. GREEN: Explore and Challenge Scratch GPIO: Pi-Stop Traffic Sequence – Create your own traffic light sequence and learn how to use Scratch GPIO with the Pi-Stop.
  4. GREEN: Explore and Challenge Scratch GPIO: Pi-Stop Reaction Game – How fast are your reflexes? Test your reaction time with the Pi-Stop Reaction game.
  5. GREEN: Explore and Challenge Scratch GPIO: Pi-Stop Simon Memory Game – Challenge your memory and get the highest score!




I will have some copies of my book available to buy (a great Fathers day gift!), plus a selection of my kits, so your Raspberry Pi fun can continue when you get home.

I look forward to meeting everyone, and I hope you all have an excellent day!



Not able to make the workshop?

Don’t worry, I will also be making all the workshop material and lots more supporting material freely available after the event (via github in markdown format & as generated PDFs).

The aim will be to build a resource of materials which anyone can download, adjust and use for their own workshops, classes or just at home in their own projects.

Hopefully people will also add their own materials, and also adapt them for other similar boards/kits.


Breadboard & Components Hobby/Education Kit for Raspberry Pi (Chapter 6 Hardware Kit)


The mini breadboard kit includes some of the components used in Chapter 6 of my book, plus are ideal for a number of starter projects (traffic lights, RGB colour mixing, timed response challenge, memory game etc).

The mini breadboard kit includes some of the components used in Chapter 6 of my book, plus are ideal for a number of starter projects (traffic lights, RGB colour mixing, timed response challenge, memory game etc).


Mini-Breadboard Kit

The mini-breadboard kit includes all the components needed to complete several small hardware projects.  This kit is intended to provide all the parts you need to complete the following recipes from my book:

  • Controlling an LED
  • Responding to a Button
  • Controlled Shutdown Button

Add a Self-Solder Combo Kit

The Mini-Breadboard & Self-Solder Combo Kit contains everything to complete all the examples in Chapter 6 of the book, including two self-solder kits (the RGB-LED and D-Pad modules used in the more advanced recipes).

Mini-Breadboard & Self-Solder Combo Kit - For everything in Chapter 6

Mini-Breadboard & Self-Solder Combo Kit – For everything in Chapter 6

The Mini-Breadboard & Self-Solder Combo Kit contains everything to complete all the examples in Chapter 6 of the book, including two self-solder kits (the RGB-LED and D-Pad modules used in the more advanced recipes).

RGB-LED Kit B (Includes GPIO Cable)

Used in the following sections in Chapter 6 of the book:

  • Multiplexed color LEDs
  • There’s more… Hardware Multiplexing
  • There’s more… Displaying random patterns
  • There’s more… Mixing multiple colors

There are also lots of lessons already on the site for the RGB-LED kit

D-Pad / Game Controller Kit B (Includes GPIO Cable)

Used in the following sections in Chapter 6 of the book:

  • The GPIO keypad input
  • There’s more… Generating other key combinations
  • There’s more… Emulating mouse events
  • See also – Can also be used with the game examples created in Chapter 4
I hope by providing these kits people can try out all the examples and material now available, and enjoy using hardware and electronics with the Raspberry Pi.

See the Breadboard & Components Kit (Ch6 Kit) product page for more details, or the Shop to purchase.

Note regarding the hardware in other chapters of the book:

I currently do not have plans to release kits for the other chapters 7, 8, 9 and 10.  This is because these chapters mainly make use of existing hardware modules which are available to buy directly from other retailers.  If I were to stock all of the modules used I would need to buy for them for the same price and then add extra (to cover my time, cost of stock etc etc).  I would have to take an existing product, add a markup and sell it on.  Unfortunately I don’t have the time and resources to do this cost effectively, therefore, it would not provide good value for money for people.

The book contains details on the places which stock the items, but let me know if you have difficulty getting a particular item so I can find an alternative and provide details on the website.


In recent months I’ve had issues charging my phone, it became apparent that some chargers were more effective than others, and it seemed that some of my USB cables were better than others.

The setup

To put this to the test I’m going to use a USB Voltage and Current monitor I purchased for measuring the power requirements of the Raspberry Pi.  If you search around this can cost a few dollars (http://www.dx.com/p/usb-av-usb-power-current-voltage-tester-translucent-blue-silver-235090).

4.94V being supplied.

4.94V being supplied.

Read the rest of this entry »

From the book…Stop-frame Animation!

I learnt so many new things during the course of writing the book, many of which I wanted to share with my kids to enjoy (but due to the tight deadlines this was often not possible).

Now that the mammoth task of the book has been completed it I thought it only fair I spent some doing some of the activities with them.

Early Saturday morning, ready for the workshop!

@Bristol Science Center is an excellent place to visit

As it happens, we visited @Bristol a few weekends ago (readers of previous posts will know this is the home of the Bristol Digi-Makers events, which we attend for the MagPi stand), this time though we were visiting the science center which is its main purpose.

We had a fab time, but it was an ultra busy weekend so we were unable to have a go on the Aardman Animation desks (Aardman amongst other things were responsible for Nick Park’s Wallace and Gromit).

Thankfully, it is something which a Raspberry Pi with a camera module can achieve and one of the things I’ve been wanting to do anyway.

Chapter 8 – Creating Projects with the Raspberry Pi Camera Module – Recipe – “Creating a stop frame animation”

The project was done using “Chapter 8 – Creating Projects with the Raspberry Pi Camera Module” of my Raspberry Pi Cookbook for Python Programmers book, which has a full recipe called “Creating a stop frame animation”.

Find out how we got on at the following page…Ch8…Example: Creating a stop frame animation


D-Pad / Game Controller Learning Module Hobby/Education Kit for Raspberry Pi



This kit is one of the hardware items used in Chapter 6 -Using Python to Drive Hardware of the new book.

For more details, see the product page and visit the PiHardware shop for details on how to purchase it.

D-Pad Controller

This will allow us to cover inputs in some new lessons.  Also, the user manual includes example code to allow you to map keyboard commands to the D-Pad buttons, converting it into a handy little game controller or keypad.

As always, the kit comes with an extensive user manual with clear and detailed instructions, explaining the design and function through to assembly and testing.

So with or without the book the kit should make an excellent project.

For your comfort, a thick foam backing is supplied for those extended gaming sessions!


I would like to add, that it has undergone extensive testing with the Spectrum version of Bruce-Lee (Datasoft/US Gold 1984), via Fuse!  Many an hour spent completing the original game some time ago.