I wonder if it would be practical to McGyver a solution into place by coiling some wire around / next to the dryer's power cable - to detect flowing current - and connecting the coil to an Arduino / Raspberry Pi
My understanding is that detecting an electrical current through a power cord typically doesn't work when measuring all the wires together, because the current in the live wire is canceled out by the return current in the neutral wire. This is why clamp-style meters are usually put at the electrical panel, where individual wires are accessible. Since I live in an apartment, that isn't an option for me.
It's also possible that your machine lets off some elecromagnetic noise you can detect directly.
The other thing you could try is put some sort of a microphone / vibration on it, then train a small NN on the waveform to distinguish between the washer and dryer.
My understanding is that detecting an electrical current through a power cord typically doesn't work when measuring all the wires together, because the current in the live wire is canceled out by the return current in the neutral wire. This is why clamp-style meters are usually put at the electrical panel, where individual wires are accessible. Since I live in an apartment, that isn't an option for me.