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Beginner Post: ESP32 WROOM Circuit Help

Posted: Wed Jun 17, 2020 1:22 am
by Shaunaaaa
Hoping I can get some help to power and monitor the output of the attached schematic. How can this be connected this to an ESP32 WROOM to monitor pulse output? I'm mainly concerned about overloading issues, the sketch isn't a problem? Power being supplied from the 5V (VIN) p

Re: Beginner Post: ESP32 WROOM Circuit Help

Posted: Wed Jun 17, 2020 3:30 am
by Beowulff
The LED can be powered from 3.3v, through a dropping resistor (value is not critical, I’d start with 200Ω).
The photodetector needs 5v, so its output needs to be connected to a resistor to act as a voltage divider. Since the pullup resistor is 10KΩ, putting a 10KΩ resistor to ground will limit the “High" voltage to 2.5v, which is safe for the input of the ESP32, and is valid logic “1"