Hardware design


How to avoid the VDD3P3_RTC being powered down after ESP32 entering light-sleep mode?

After ESP32-WROVER-B entering light-sleep mode, the GPIO levels corresponding to pads powered by VDD3P3_RTC may be decreased. It is generally because of the power-down of RTC after entering light-sleep mode. Please call esp_sleep_pd_config(ESP_PD_DOMAIN_RTC_PERIPH, ESP_PD_OPTION_ON) to maintain the power supply of RTC.

The pins for I2S signals

The pins for I2S signals are located far apart from one another in the reference designs provided by Espressif. Can these pins be located closer together? For example, configure all the I2S signals to GPIO5, GPIO18, GPIO23, GPIO19 and GPIO22; and configure all the I2C signals to GPIO25 and GPIO26, or GPIO32 and GPIO33.

All I2S I/Os can be allocated freely. Please note that some I/Os can only be used as input pins. For details, please refer to the last page of ESP32 Datasheet.

What are the general power supply requirements of the ESP8266?

  • Digital voltage requirement: 1.8 V - 3.3 V

  • Analog voltage requirement: 3.0 V - 3.6 V (The lowest possible analog voltage is 2.7 V.)

  • Peak analog circuit current: 350 mA

  • Peak digital circuit current: 200 mA

Note: CHIP_EN works at 3.0 V - 3.6 V, please use a level converter to ensure compatibility with digital logic at 1.8 V.