13th Egham Raspberry Jam

On Sunday 22nd January I travelled down Egham to attend the 13th Egham Raspberry Jam, it's my second time I have attended this particular jam. It was held at the Gartner UK HQ offices, which was easy to find and had plenty of parking. There were plenty of cool show and tell projects to look at, but no workshops or talks.

I took a couple of micro:bit projects and my Christmas decoration project along. I spent most of my time talking to people about my projects, however I did manage to have a look at the other projects on show.

Some of my projects on display.

Zbit:bod

A nice collection of Zbit boards from Nevil Hunt.

Musical Octopus, using the awesome Makey Makey board.


IoT controlled Sense hat by Nigel Stirzaker.


Scratch controlled Lego train.


RetoPie by Albert Hickey.


Some more pictures can be found on my Flickr page. 

Micro Simon

I recently stumbled across some excellent micro:bit resources on this website,  I liked the look of the micro Python Simon game project so I built the project to try it out.  

 Micro Python Simon game 

More details about the BBC micro:bit  Simon Game I used as a starting point can be found here  

This gave me an idea, could I connect a micro:bit to an vintage MB Simon game hmmm.   The original full sized game uses a custom MB Electronics processor (the MB4850) which performs nearly all of the functions for the game. The only other significant piece of electronics is a SN75494N chip which interfaces the processor to the light‐bulbs and the built in speaker.

After a quick hunt on eBay for a broken Simon game, I managed to find one cheap. While I waited for the game to arrive, I knocked up a quick circuit with some 2.5v MES light bulbs and a ULN2003A Darlington transistor array to drive the bulbs. Now for the next part of my cunning plan….

Testing my idea

Breadboard Layout - Showing added bulbs and ULN2003A 

When the game arrived I duly took it apart, sadly it didn’t work and was pretty beaten up, oh well. I found some useful information about these classic Simon games here, included on the site was a schematic which helped me trace out the PCB layout so I could tap into the existing bulb and switch circuits. 

MB Simon secrets revealed 

Simon circuit board top view

Simon circuit board bottom view

More testing 

I removed the existing custom processor and SN75494N chip and soldered some new wires to the existing colour switches and bulbs.   I then connected these to my existing breadboard layout and gave it a quick whirl.  It worked brilliantly, another awesome micro:bit hack in the bag.

Finished project

#projectSimon is finished oh yeah..... #microbit @whaleygeek @microbit_edu pic.twitter.com/LA4Hd3uOSX

— Thomas Stratford (@MrTomsWorld) January 10, 2017

Finally I modified the existing code, which can be found on my github.

Update 12th February 2017

I took my Micro Simon game out on the road and it performed well but the bulbs weren't very bright.  Despite some experimenting to see if I could get the bulbs any brighter, I couldn't so I decided to build some LED modules to replace the existing bulbs.  I brought some of these TruOpto OSPW5111P high intensity white (30000mcd) LED's from Rapid Electronics and set about building the LED modules on a small piece of stripboard.

LED Modules completed.

I removed the existing bulb holders from the MB Simon game PCB and installed the LED modules.

A final test 

My improved #microbit Micro Simon is up and running.. @microbit_edu @whaleygeek pic.twitter.com/Ra1jiO5kpE

— Thomas Stratford (@MrTomsWorld) 12 February 2017