In your ESP32 Deep Sleep – External Wake Up lesson, you talk about a pullup resistor but didn’t really say much about a pulldown resistor or show it’s use or schematic or sketch. If you are trying to put the ESP32 to sleep and use minimal power, which would be better and why?
What part of the unit are you referring to? Is this text in the code example?
/* First we configure the wake up source We set our ESP32 to wake up for an external trigger. There are two types for ESP32, ext0 and ext1 . ext0 uses RTC_IO to wakeup thus requires RTC peripherals to be on while ext1 uses RTC Controller so doesnt need peripherals to be powered on. Note that using internal pullups/pulldowns also requires RTC peripherals to be turned on. */
Basically, this text means that if we wanted to configure internal pull-up or pull-down resistors, the RTC peripherals should be turned on. However, we don’t use internal pull-up or pull-down resistors (these should be defined in the code).
In our examples, we’re using external pull-down resistors (physical resistors that are connected to GND). See our schematic diagrams below:
We don’t configure any pull-up or pull-down internal resistors in the code.
I’m not really sure if I understood your question or if this answers your doubts.
Let me know what you think.