This is (largely) what I have for my "dumb" washer. What makes mine unique is the washer is in my apartment building's cellar, too far for Wifi. So I have a LoRa transmitter that routes the message to a LoRa receiver on my home network.
Unfortunately, as you noted, I haven't figured out how to handle the dryer as the load is too much for all the smart plugs I've found. I wish there was a clamp-style monitor on an extension cord, but it seems that is something which doesn't exist.
Thankfully, the dryer isn't as much of an issue since dry clothes can sit there until I remember to get them.
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.
I considered that, but the washer and dryer are stacked (limited space) so the vibrations of the washer would be picked up in a dryer vibration sensor.
Is that really a problem though? If you're washing another load at the same time as the dryer is running, wouldn't you generally want to wait until both are done anyways so you can swap the wash to the dryer after getting the dry load out?
Also at least in my experience the dryer takes longer to run than the washer, so if I've just rotated a previous load and started both at the same time I'm always waiting on the dryer to be able to do the next one.
Not always. I only put sheets and towels in the dryer, everything else gets hung up. So I may do two or even three washing loads in the time of a single dryer load (it can be very slow). So I'm much more interested in when the washer finishes than the dryer.
Unfortunately, as you noted, I haven't figured out how to handle the dryer as the load is too much for all the smart plugs I've found. I wish there was a clamp-style monitor on an extension cord, but it seems that is something which doesn't exist.
Thankfully, the dryer isn't as much of an issue since dry clothes can sit there until I remember to get them.