Sdio; Touch Sensor - Espressif Systems ESP32 Hardware Design Manuallines

Chapter 3. Schematic Checklist

3.11 SDIO

There are two sets of GPIOs (slot0 and slot1) that can be assigned to SDIO on ESP32, as shown in Table
Configuration. When ESP32 works as an SDIO host or slave, connect GPIOs in slot1 to signal lines.
CMD CLK
Slot0 GPIO11 GPIO6
Slot1 GPIO15 GPIO14
When connecting GPIOs in slot1 to signal lines, please note:
• When ESP32 works as an SDIO host, it is recommended to add pull-up resistors on the used pins. Unused
pins can be utilized for other purposes.
• When ESP32 works as an SDIO slave, add pull-up resistors on all pins, regardless of whether these pins are
used for SDIO or not. Unused pins cannot be used for other purposes.
For more information on SDIO configuration, please refer to

3.12 Touch Sensor

When using the touch function, it is recommended to populate a zero-ohm series resistor at the chip side to reduce
the coupling noise and interference on the line, and to strengthen the ESD protection. The recommended resistance
is from 470 Ω to 2 kΩ, preferably 510 Ω. The specific value depends on the actual test results of the product.
Espressif Systems
Fig. 15: ESP32 Schematic for External Capacitor
Table 7: SDIO Pin Configuration
DAT0 DAT1 DAT2
GPIO7 GPIO8 GPIO9
GPIO2 GPIO4 GPIO12
20
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DAT3 Note
GPIO10 Used to connect flash by de-
fault.
other use.
GPIO13 Multiplexed with JTAG, touch,
EMAC, and strapping func-
tions.
API References.
SDIO Pin
Not recommended for
Release master