By default, the Waveshare ESP32-S3 Touch 7B uses UART0 for serial communication (logging and monitoring).

However, in many real-world projects, you may need to:

• Free UART0 for USB debugging

• Use another UART for external devices (sensors, modules, etc.)

• Avoid conflicts with flashing and logs

In this guide, you will learn how to switch from UART0 to UART1 using ESP-IDF.

🧠 Understanding UART on ESP32-S3 Touch 7B waveshare

• UART0 → Default (used for flashing and logs)

• UART1 → Available for custom use

• UART2 → Optional (depending on configuration)

👉 UART signals can be routed to different GPIOs, making it very flexible.

⚙️ Step 1: Change Console Output to UART1

before you change UART 0 to UART1 you must change selector to UART selected

Open your project in ESP-IDF and run:

idf.py menuconfig

Navigate to:

Component config → ESP System Settings → Channel for console output

Change:

UART0

To:

UART1

🔌 Step 2: Configure UART1 Pins

Add this code in your main.c:

#include "driver/uart.h"

#define UART_PORT UART_NUM_1
#define TXD_PIN 17
#define RXD_PIN 18

void app_main(void)
{
    uart_config_t uart_config = {
        .baud_rate = 115200,
        .data_bits = UART_DATA_8_BITS,
        .parity    = UART_PARITY_DISABLE,
        .stop_bits = UART_STOP_BITS_1,
        .flow_ctrl = UART_HW_FLOWCTRL_DISABLE
    };

    uart_driver_install(UART_PORT, 1024, 0, 0, NULL, 0);
    uart_param_config(UART_PORT, &uart_config);
    uart_set_pin(UART_PORT, TXD_PIN, RXD_PIN, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE);
}

🔨 Step 3: Build and Flash

idf.py build
idf.py flash

📟 Step 4: Monitor UART1 Output

Since logs are now on UART1:

• Use a USB-to-TTL converter

• Connect:

  • TX → RX

  • RX → TX

Then open a serial monitor (PuTTY, Arduino Serial Monitor, etc.)

⚠️ Important Notes

• Avoid GPIO pins used by the LCD (Waveshare display)

• Make sure selected pins are free

• UART0 is still used during flashing (unless using USB CDC)

🎯 Conclusion

Switching from UART0 to UART1 allows you to:

• Separate debugging and communication

• Improve system flexibility

• Build more advanced ESP32-S3 projects

With ESP-IDF, you have full control over UART configuration.

🚀 Next Topics

• ESP32 UART Communication Example

• ESP32-S3 USB CDC vs UART

• LVGL + UART Data Integration

   Read also : 🚀 Getting Started ESP-IDF with PowerShell & Espressif IDE (Beginner Guide)