ESP32 Arduino IDE version for pulsesensor what's new #define ESP32 uses 2msec interrupt for ESP32 derived from https://github.com/WorldFamousElectronics/PulseSensor_Amped_Arduino GPIO34 is changed from A0 for signal input LED5 is faded by LEDC timer interrpt code https://github.com/espressif/arduino-esp32/blob/master/libraries/ESP32/examples/Timer/RepeatTimer/RepeatTimer.ino recommended http://www.instructables.com/id/Arduino-Pulse-Sensor-Cardio-Graph/