Data Sheet

Table Of Contents
Appendix A
Appendix A ESP32 Pin Lists
A.1. Notes on ESP32 Pin Lists
Table 24: Notes on ESP32 Pin Lists
No. Description
1
In Table IO_MUX, the boxes highlighted in yellow indicate the GPIO pins that are input-only.
Please see the following note for further details.
2
GPIO pins 34-39 are input-only. These pins do not feature an output driver or internal pull-
up/pull-down circuitry. The pin names are: SENSOR_VP (GPIO36), SENSOR_CAPP (GPIO37),
SENSOR_CAPN (GPIO38), SENSOR_VN (GPIO39), VDET_1 (GPIO34), VDET_2 (GPIO35).
3
The pins are grouped into four power domains: VDDA (analog power supply), VDD3P3_RTC
(RTC power supply), VDD3P3_CPU (power supply of digital IOs and CPU cores), VDD_SDIO
(power supply of SDIO IOs). VDD_SDIO is the output of the internal SDIO-LDO. The voltage of
SDIO-LDO can be configured at 1.8 V or be the same as that of VDD3P3_RTC. The strapping
pin and eFuse bits determine the default voltage of the SDIO-LDO. Software can change the
voltage of the SDIO-LDO by configuring register bits. For details, please see the column “Power
Domain” in Table IO_MUX.
4
The functional pins in the VDD3P3_RTC domain are those with analog functions, including the
32 kHz crystal oscillator, ADC, DAC, and the capacitive touch sensor. Please see columns
“Analog Function 1~3” in Table IO_MUX.
5
These VDD3P3_RTC pins support the RTC function, and can work during Deep-sleep. For
example, an RTC-GPIO can be used for waking up the chip from Deep-sleep.
6
The GPIO pins support up to six digital functions, as shown in columns “Function 1~6” In Table
IO_MUX. The function selection registers will be set as N-1”, where N is the function number.
Below are some definitions:
SD_* is for signals of the SDIO slave.
HS1_* is for Port 1 signals of the SDIO host.
HS2_* is for Port 2 signals of the SDIO host.
MT* is for signals of the JTAG.
U0* is for signals of the UART0 module.
U1* is for signals of the UART1 module.
U2* is for signals of the UART2 module.
SPI* is for signals of the SPI01 module.
HSPI* is for signals of the SPI2 module.
VSPI* is for signals of the SPI3 module.
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ESP32 Series Datasheet v3.5