Aha! Got it working now, thanks!

Hi, I just started figuring out the esp32, and by the technical docs, GPIO_OUT_REG should be a R/W register indicating current pin status. However after a simple test: void setup() { Serial.begin(115200); REG_WRITE(GPIO_ENABLE_REG, BIT4); } void loop() { REG_WRITE(GPIO_OUT_REG,BIT4); delay(500); Ser...