ESP32 Forum

When we used SD_MMC arduino library, UART1 and I2C are not working.
UART1 Pins we use are: GPI36 for Rx and GPIO4 for Tx.
I2C Pins we use are: GPIO16 for SCL and GPIO13 for SDA.

UART1 Setup - Arduino Code:
---------------------------
#include <HardwareSerial.h>

static HardwareSerial UART1(1);

UART1.begin(BAUD_RATE, /* baud speed */
SERIAL_8N1, /* UART mode */
36, /* RX pin */
4 /* TX pin. */
);

SDMMC Setup - Arduino Code:
---------------------------
#include "FS.h"
#include "SD_MMC.h"

if(!SD_MMC.begin())
{
Serial.println("Card Mount Failed");
return;
}

I2C Setup - Arduino Code:
---------------------------
#include <Wire.h>
#include "RTClib.h"

/* I2C Pins & Frequency */
#define SCL 22 // Mapped SCL to GPIO21
#define SDA 21 // Mapped SDA to GPIO122
#define FREQ 100000

RTC_DS3231 RTC;

Wire.begin(SDA, SCL, FREQ); // SDA, SCL, Frequency
RTC.begin();

Please help us to resolve this issue.

Sdmmc uses pins 2,4,12,13,14,15

Thanks for reply.
Please refer Olimex ESP32 EVB schematics, sdmmc uses GPIO15 (data in), GPIO2 (data out) and GPIO14 (clock).