My 7 year old has a fascination with robots and how they operate, sensors, motors, communication etc. As a mechanical engineer I am limited to how I can fulfil this interest. I think his interest is types that have an element of life (humanoid, dog, cat etc.). I am wondering around a suitable starting kit that we can build together. Not too basic, but not too complex. Not too cheap, but not too expensive, perhaps £150 max? I’d appreciate any help ordirection. Thank you.