Interactive Light Up Window using a Raspberry Pi and micro:bit -- Episode 527

Excellent !  

Next challenge - turn your front window into a rhombic dodecahedron infinity mirror... 

I've done it! I used a time of flight sensor

If you think that ornaments secured on the wall would survive, then that perhaps opens up some possibilities for tactile input options. Small artificial Xmas trees fitted with resistive flex sensors that will generate a varying signal with decay when brushed against could generate interesting lighting. ( I recall Tom Igoe sewing such sensors into limbs of cuddly toys to act as a user interface). Likewise reindeer with noses that glow red when touched / pressed. Standardise the base and you could have different ornaments for the different seasons such as a flexible cat's tail, and light up pumpkins which can be pressed. Endless fun with the 3D printer.

Perhaps could have a 'Simon' type memory game where robust buttons or touch sensors light up and you have to repeat the sequence shown by the lights in the window. With games though you generally need some sort of a reward if successful e.g. Santa Claus appearing out of your chimney...

LED light chaser hoops can be quite eye-catching and relatively easy to do with pixel LED strips. You can add to them over time as well. You can have lots of patterns that can be controlled over your user inputs. Relatively easy to weatherproof and secure.

A step up might be to use persistence of vision wheels which then allows for animated text and graphics in addition to colour changing. Perhaps could be upcycled from old bicycle wheels if you don't want to design from scratch.

Just need a 'garden network' to connect them all into 

I think this depends on what you plan to do with the input triggers, along with aspects such as weatherproofing, robustness, and as previously mentioned physical restraints ( I doubt the council will take kindly to you digging up the pavement, even if they appear to let everyone else do it these days...).

You could have some sort of 'button wall' along the top of the wall but then what does each button do. If you had more of a video display in the window you could start to do giant retro video games with the controllers located on the wall.

With the RGB LEDs you could perhaps have a colour sensor to match the colour in the window to someone's clothing. Lighting could be tricky here so it may have to be a sleeve in close proximity to a sensor rather than someone walking past. 

With Bluetooth input, you could have an app that allows neighbours to program their own light show and run it when passing the house. However you may need to add more lights for this.

I was initially thinking more of gobo projection. Something like projecting a sequence of animal footprints as people walk past. Depends on how brightly lit the pavement is though.

You could probably back project onto the window, or use transparent LED film, which would open up all sorts of interactivity options.

Apropos of capacitive sensors, I had wanted to put squares of mesh (e.g. chicken wire) under the welcome mat to detect when someone stepped on it. You could make mats of all different colo(u)rs.

What inputs should I use for my next video??

Definitely working on more sensors for my next video. Projecting onto the footpath would be tough given the angles, weather and closeness of the road. I actually projected out a bedroom window onto the front garden, it was fun! But not visible from the path

Perhaps work  your way up to a 'smart wall' - modular blocks that can house sensors, lights, displays, project onto the pavement...