Ask HN: I have a crazy idea. How do I approach VCs?

Hi,

I have a crazy idea for a product. Well, the product itself is more of an 'experience', if that makes any sense. Now, the product would need a HW component + embedded sw + mobile app + backend apps + IT infrastructure.

When I approach VCs, do I build prototypes for all these and then take it to them ? The product as a whole, would need all these components to deliver the experience. Which one do I build first? I mean, I could buy an RPi/ arduino and prototype the hw component, but it would be incomplete without the other parts. Or do I just have architectural diagrams(ie, how all the components work together) on the presentation?

Thanks!