Hey there, I've been reading a book about IoT and I found something that didn't make much sense to me. The author said the thermostat worked as a variable resistor, so he calculated the charging time to get the 'thermostat resistor' value. The thing is, he said that GPIO #1 worked as an output and GPIO #4 worked as an input. So, he set #1 as HIGH, and then he measured the time until #4 was HIGH, subtracted those times and like so, got the charging time. I mean, it has it's logic, afterall, the eletrons in the capacitor will start to push back with the same force of the source when the capacitor is charged, the thing is, #4 is working as an open circuit, therefore it will always have the same value as #1, right?