We represent the Lollipop League

Thanks for bearing with us while we took the Easter break off – we return to you refreshed and full of chocolate.

The marvellous Spencer Organ, one of our Certified Educators, is a teacher at King Edward VI Sheldon Heath Academy (KESH Academy to its friends) in Birmingham. The school recently put on a student performance of The Wizard of Oz.


Spencer was in charge of performance technology, and wanted to see if he could fit a Raspberry Pi in as special effects equipment. The Tin Man’s heart presented a perfect opportunity. Spencer used the Pimoroni Unicorn HAT with a Model A+ to make the Tin Man’s heart (which was made out of red foil back when I did the same play as a kid) a glowing, animated thing of wonder. For more on HATs, see James’ post from last year.

(Spencer sensibly tweaked the brightness settings; a Unicorn HAT at full blast is positively retina-searing.)


The heart was programmed to pulse, giving the audience the impression it was beating.

Spencer says:

The code was relatively simple and I used a simple list to assign the x,y and colour data for each pixel to be used.


To give the effect of the heart beating and pulsating I gradually changed the brightness of the pixels from about 30 – 80%. It was important not to go too bright as I could have blinded the audience or other cast members!

while True:
    for bright in range (30,80):

This gave a very passable beating effect which looked stunning on the stage. The Pi was powered with a portable battery pack and to make backstage life easier the code was activated from boot using crontab with:

@reboot sudo python /home/pi/Pimoroni/heart.py &

Spencer has made the Python script you’ll need to make your own available on his website; check out the Raspberry Pi section of his blog for more teaching and learning ideas with the Pi. Thanks Spencer!



That is fantastic. I was one of the flying monkeys for my school’s performance of The Wizard of OZ. This appears to be a much more up market performance to ours, all those years ago (in the great southern land of OZ).


This is such a great use of hardware! Really awesome!


guild… guild… we represent the lollipop GUILD!

*wanders off tutting to himself* :-p

Great use of a Pi though, well done :-)

Liz Upton

Aargh – you’re right! I am confusing the Lollipop Guild with the Lullaby League. (Too late to change it now – permalinks and all that. It’ll be a lasting monument to my shame.)


Another one to add to the list. It’s getting quite long now. I might need to buy a new notebook soon :P

Liz Upton

Oh, pthwap.


You filled up a terabyte drive on a notebook computer with Liz gaffs? Geez, I woulda thought a 16 GB tablet would have been big enough :D LOL, as in Lots of Love! We sexy sexagenarians are laughing with you, not at you … well, not in front of you, at least ;)


That is such a nice use of the UnicornHat.


Did the Lollipop Guild and the Lullaby League merge to become the Lollypop League.


As Baldrick would say, (thanks to Spencer) “I have a cunning plan !

Great projet. Inspirational!

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