Red Nose Day Door of Mystery


Sometimes a good idea can take away your entire Sunday.

“The Door of Mystery” is an unique fundraising idea that takes the old style, simple, raffle idea and turns it into a new, high-tech, complicated form. To take part all you have to do is buy one of our special “Red Nose Day” tags for two pounds and then take it to “The Door of Mystery” at my office in the Robert Blackburn building to find out your entry number. Then, at the presentation on Friday we will build a “Door of Mystery” machine of our own and then use it to pick the winner of the competition. The prize, courtesy of Microsoft Research Cambridge, is a Gadgeteer kit of your own.

The tags contain an RFID chip which is read by a Gadgeteer board inside the door unit. The unit contains an SD card with a list of RFID values which are mapped to entry numbers. Show your tag to the door and it will tell you your magic number.


This is the guts of the prototype device. I’ve cannibalised my Tweet Printer case to use for the project. I’m going to print a proper one later. If I get round to it.


I’ve got 100 RFID tags to sell for Comic Relief. Each one has been keyed to the system and you can buy them from the departmental office. Perhaps we’ll think of other uses for them over time..

You can sponsor the whole shebang over at: