UART1 Init

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 };
//Configure UART1 parameters
    uart_param_config(UART_NUM_1, &uart_config);

    uart_set_pin(UART_NUM_1, 21, 13, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE);
    uart_driver_install(UART_NUM_1, BUFFER_SIZE * 2, BUFFER_SIZE * 2, 0, NULL, 0);