diff --git a/main/main.c b/main/main.c
index b770382..0a38b8a 100755
--- a/main/main.c
+++ b/main/main.c
@@ -40,13 +40,14 @@ void app_main(void)
     cdc_acm_msc_init();
     vTaskDelay(10);
     userShellInit();
-    cdc_printf("Hello world!\n");
+    vTaskDelay(10);
+    cdc_printf("Hello world!\r\n");
 
     /* Print chip information */
     esp_chip_info_t chip_info;
     uint32_t        flash_size;
     esp_chip_info(&chip_info);
-    printf("This is %s chip with %d CPU core(s), %s%s%s%s, ", CONFIG_IDF_TARGET,
+    cdc_printf("This is %s chip with %d CPU core(s), %s%s%s%s, ", CONFIG_IDF_TARGET,
            chip_info.cores,
            (chip_info.features & CHIP_FEATURE_WIFI_BGN) ? "WiFi/" : "",
            (chip_info.features & CHIP_FEATURE_BT) ? "BT" : "",
@@ -57,17 +58,17 @@ void app_main(void)
 
     unsigned major_rev = chip_info.revision / 100;
     unsigned minor_rev = chip_info.revision % 100;
-    printf("silicon revision v%d.%d, ", major_rev, minor_rev);
+    cdc_printf("silicon revision v%d.%d, ", major_rev, minor_rev);
     if (esp_flash_get_size(NULL, &flash_size) != ESP_OK) {
-        printf("Get flash size failed");
+        cdc_printf("Get flash size failed");
         return;
     }
 
-    printf("%" PRIu32 "MB %s flash\n", flash_size / (uint32_t)(1024 * 1024),
+    cdc_printf("%" PRIu32 "MB %s flash\r\n", flash_size / (uint32_t)(1024 * 1024),
            (chip_info.features & CHIP_FEATURE_EMB_FLASH) ? "embedded"
                                                          : "external");
 
-    printf("Minimum free heap size: %" PRIu32 " bytes\n",
+    cdc_printf("Minimum free heap size: %" PRIu32 " bytes\r\n",
            esp_get_minimum_free_heap_size());
 
     // for (int i = 10; i >= 0; i--) {
@@ -83,19 +84,19 @@ void app_main(void)
         vTaskDelay(1000 / portTICK_PERIOD_MS);
     }
 
-    printf("Restarting now.\n");
+    cdc_printf("Restarting now.\r\n");
     fflush(stdout);
     esp_restart();
 }
 
 static void _show_build_time(int argc, char** argv)
 {
-    cdc_printf("build at %s %s\n", __DATE__, __TIME__);
+    cdc_printf("build at %s %s\r\n", __DATE__, __TIME__);
 }
 
 static uint8_t imp_restart_esp()
 {
-    cdc_printf("Restarting now.\n");
+    cdc_printf("Restarting now.\r\n");
     vTaskDelay(10);
     esp_restart();
 }