esp_random() function

Get one random 32-bit word from hardware RNG If Wi-Fi or Bluetooth are enabled, this function returns true random numbers. In other situations, if true random numbers are required then consult the ESP-IDF Programming Guide "Random Number Generation" section for necessary prerequisites. This function automatically busy-waits to ensure enough external entropy has been introduced into the hardware RNG state, before returning a new random number. This delay makes sure the reading frequency does not exceed 15-75 KHz. The actual value is dependent on the specific chip. More information on this can be found in components/esp_hw_support/hw_random.c.