Need handmade On Air Bed Sensor

Hi. I have airbed (air mattress). Would like to have sensor which can detect if i placed on it. Tried to do something like by layers: air bed aluminium foil layer connected to analog pin/vcc/gnd (tried differect combination) textile aluminium foil layer connected to - analog pin/vcc/gnd (tried differect combination) wooden floor

When i just placed on bed values goes up but after some time goes down even less then arranger value. And one more issue: analog PIN gives sinusoid values. Maybe need some capacitor and coaxial cable... (i'm noob about about electronic btw). Any suggestion how to detect when i placed on air bed? Thanks

you need an air-pressure sensor I think.

i have no good way to put sensor inside.... need some kind of external one...

put a load cell underneath?

i think hard to do with load cell, cuz weight much depends where ur body placed on bed(queen size)...