Before you change to the other circuit and device type, try running this with:
static st::PS_Voltage sensor3(F("power1"), 15, 0, PIN_VOLTAGE, 0, 1023, 0, 64000, 1, 100);
static st::PS_Voltage sensor3(F("power1"), 15, 0, PIN_VOLTAGE, 0, 1023, 0, 64000, 1, 5);
Be sure to record some time at the end of the cycle where you are trying to determine that the cycle is complete. I think you might be able to get a better look at the signal with one of these device configurations.
Even with the data you collected, looking for a value less than 1 for more than 2 minutes would give you an indicator that the dryer was no longer running.
Edit: looking at the data more carefully, I see a couple things. The transition from heater on to heater off has a shape that is likely driven by the low pass filter frequency being extremely low. I would reduce the capacitor size to address this.
Your dryer has 3 states:
- motor on
- motor and heat element on
State 3 is easy to see. The magnitude of state 3 is so large compared to state 2 that it makes seeing state 2 on the plot very difficult. I wonder if you could distinguish the difference between state 2 and state 1 if the existing data was plotted with a vertical axis maximum of 1 instead of 10. State 3 would be off the chart, but that's ok.