diff --git a/demo/audio_v1_mic_singlechan_template.c b/demo/audio_v1_mic_singlechan_template.c
index 59fbaa74..c10275dc 100644
--- a/demo/audio_v1_mic_singlechan_template.c
+++ b/demo/audio_v1_mic_singlechan_template.c
@@ -120,11 +120,11 @@ volatile bool tx_flag = 0;
 void usbd_audio_open(uint8_t intf)
 {
     tx_flag = 1;
-    printf("OPEN\r\n");
+    USB_LOG_RAW("OPEN\r\n");
 }
 void usbd_audio_close(uint8_t intf)
 {
-    printf("CLOSE\r\n");
+    USB_LOG_RAW("CLOSE\r\n");
     tx_flag = 0;
 }
 
@@ -148,7 +148,7 @@ void audio_init()
     usbd_audio_add_interface(&audio_class, &audio_stream_intf);
     usbd_interface_add_endpoint(&audio_stream_intf, &audio_in_ep);
     usbd_audio_add_entity(0x02, AUDIO_CONTROL_FEATURE_UNIT);
-    
+
     usbd_initialize();
 }
 
diff --git a/demo/audio_v1_mic_speaker_dualchan_template.c b/demo/audio_v1_mic_speaker_dualchan_template.c
index d23a1ea0..8d156842 100644
--- a/demo/audio_v1_mic_speaker_dualchan_template.c
+++ b/demo/audio_v1_mic_speaker_dualchan_template.c
@@ -171,7 +171,7 @@ uint32_t actual_read_length = 0;
 void usbd_audio_out_callback(uint8_t ep)
 {
     if (usbd_ep_read(ep, out_buffer, AUDIO_OUT_EP_MPS, &actual_read_length) < 0) {
-        printf("Read DATA Packet failed\r\n");
+        USB_LOG_RAW("Read DATA Packet failed\r\n");
         usbd_ep_set_stall(ep);
         return;
     }
@@ -201,7 +201,7 @@ void audio_init()
     usbd_interface_add_endpoint(&audio_stream_intf2, &audio_out_ep);
     usbd_audio_add_entity(0x02, AUDIO_CONTROL_FEATURE_UNIT);
     usbd_audio_add_entity(0x05, AUDIO_CONTROL_FEATURE_UNIT);
-    
+
     usbd_initialize();
 }
 
diff --git a/demo/audio_v2_mic_multichan_template.c b/demo/audio_v2_mic_multichan_template.c
index fbece086..fc09d8e2 100644
--- a/demo/audio_v2_mic_multichan_template.c
+++ b/demo/audio_v2_mic_multichan_template.c
@@ -151,11 +151,11 @@ volatile bool tx_flag = 0;
 void usbd_audio_open(uint8_t intf)
 {
     tx_flag = 1;
-    printf("OPEN\r\n");
+    USB_LOG_RAW("OPEN\r\n");
 }
 void usbd_audio_close(uint8_t intf)
 {
-    printf("CLOSE\r\n");
+    USB_LOG_RAW("CLOSE\r\n");
     tx_flag = 0;
 }
 
@@ -180,7 +180,7 @@ void audio_init()
     usbd_interface_add_endpoint(&audio_stream_intf, &audio_in_ep);
     usbd_audio_add_entity(0x01, AUDIO_CONTROL_CLOCK_SOURCE);
     usbd_audio_add_entity(0x03, AUDIO_CONTROL_FEATURE_UNIT);
-    
+
     usbd_initialize();
 }
 
diff --git a/demo/audio_v2_mic_speaker_multichan_template.c b/demo/audio_v2_mic_speaker_multichan_template.c
index 1bb61cfc..2d55a4cd 100644
--- a/demo/audio_v2_mic_speaker_multichan_template.c
+++ b/demo/audio_v2_mic_speaker_multichan_template.c
@@ -199,20 +199,20 @@ void usbd_audio_open(uint8_t intf)
 {
     if (intf == 1) {
         rx_flag = 1;
-        MSG("OPEN1\r\n");
+        USB_LOG_RAW("OPEN1\r\n");
     } else {
         tx_flag = 1;
-        MSG("OPEN2\r\n");
+        USB_LOG_RAW("OPEN2\r\n");
     }
 }
 void usbd_audio_close(uint8_t intf)
 {
     if (intf == 1) {
         rx_flag = 1;
-        MSG("CLOSE1\r\n");
+        USB_LOG_RAW("CLOSE1\r\n");
     } else {
         tx_flag = 0;
-        MSG("CLOSE2\r\n");
+        USB_LOG_RAW("CLOSE2\r\n");
     }
 }
 
@@ -256,7 +256,7 @@ void audio_init()
     usbd_audio_add_entity(0x05, AUDIO_CONTROL_CLOCK_SOURCE);
     usbd_audio_add_entity(0x07, AUDIO_CONTROL_FEATURE_UNIT);
 
-    
+
     usbd_initialize();
 }
 
diff --git a/demo/audio_v2_speaker_multichan_template.c b/demo/audio_v2_speaker_multichan_template.c
index 4c831d9a..bd5cfc44 100644
--- a/demo/audio_v2_speaker_multichan_template.c
+++ b/demo/audio_v2_speaker_multichan_template.c
@@ -151,11 +151,11 @@ volatile bool rx_flag = 0;
 void usbd_audio_open(uint8_t intf)
 {
     rx_flag = 1;
-    printf("OPEN\r\n");
+    USB_LOG_RAW("OPEN\r\n");
 }
 void usbd_audio_close(uint8_t intf)
 {
-    printf("CLOSE\r\n");
+    USB_LOG_RAW("CLOSE\r\n");
     rx_flag = 0;
 }
 
@@ -180,7 +180,7 @@ void audio_init()
     usbd_interface_add_endpoint(&audio_stream_intf, &audio_in_ep);
     usbd_audio_add_entity(0x01, AUDIO_CONTROL_CLOCK_SOURCE);
     usbd_audio_add_entity(0x03, AUDIO_CONTROL_FEATURE_UNIT);
-    
+
     usbd_initialize();
 }
 
diff --git a/demo/cdc_acm_msc_template.c b/demo/cdc_acm_msc_template.c
index 78ec824a..1b7be8f0 100644
--- a/demo/cdc_acm_msc_template.c
+++ b/demo/cdc_acm_msc_template.c
@@ -113,16 +113,16 @@ void usbd_cdc_acm_out(uint8_t ep)
 
     usbd_ep_read(ep, data, 64, &read_byte);
     for (uint8_t i = 0; i < read_byte; i++) {
-        printf("%02x ", data[i]);
+        USB_LOG_RAW("%02x ", data[i]);
     }
-    printf("\r\n");
-    printf("read len:%d\r\n", read_byte);
+    USB_LOG_RAW("\r\n");
+    USB_LOG_RAW("read len:%d\r\n", read_byte);
     usbd_ep_read(ep, NULL, 0, NULL);
 }
 
 void usbd_cdc_acm_in(uint8_t ep)
 {
-    printf("in\r\n");
+    USB_LOG_RAW("in\r\n");
 }
 
 /*!< endpoint call back */
@@ -148,7 +148,7 @@ void cdc_acm_msc_init(void)
     usbd_interface_add_endpoint(&cdc_data_intf, &cdc_in_ep);
 
     usbd_msc_class_init(MSC_OUT_EP, MSC_IN_EP);
-    
+
     usbd_initialize();
 }
 
diff --git a/demo/cdc_acm_multi_template.c b/demo/cdc_acm_multi_template.c
index e89c06d9..eebd90c3 100644
--- a/demo/cdc_acm_multi_template.c
+++ b/demo/cdc_acm_multi_template.c
@@ -123,16 +123,16 @@ void usbd_cdc_acm_bulk_out(uint8_t ep)
 
     usbd_ep_read(ep, data, 64, &read_byte);
     for (uint8_t i = 0; i < read_byte; i++) {
-        printf("%02x ", data[i]);
+        USB_LOG_RAW("%02x ", data[i]);
     }
-    printf("\r\n");
-    printf("read len:%d\r\n", read_byte);
+    USB_LOG_RAW("\r\n");
+    USB_LOG_RAW("read len:%d\r\n", read_byte);
     usbd_ep_read(ep, NULL, 0, NULL);
 }
 
 void usbd_cdc_acm_bulk_in(uint8_t ep)
 {
-    printf("in\r\n");
+    USB_LOG_RAW("in\r\n");
 }
 
 /*!< endpoint call back */
@@ -196,7 +196,7 @@ usbd_endpoint_t cdc_in_ep4 = {
 void cdc_acm_multi_init(void)
 {
     usbd_desc_register(cdc_descriptor);
-    
+
     usbd_cdc_add_acm_interface(&cdc_class1, &cdc_cmd_intf1);
     usbd_cdc_add_acm_interface(&cdc_class1, &cdc_data_intf1);
     usbd_interface_add_endpoint(&cdc_data_intf1, &cdc_out_ep1);
diff --git a/demo/cdc_acm_template.c b/demo/cdc_acm_template.c
index d733c8b3..158dd2f0 100644
--- a/demo/cdc_acm_template.c
+++ b/demo/cdc_acm_template.c
@@ -108,16 +108,16 @@ void usbd_cdc_acm_out(uint8_t ep)
 
     usbd_ep_read(ep, data, 64, &read_byte);
     for (uint8_t i = 0; i < read_byte; i++) {
-        printf("%02x ", data[i]);
+        USB_LOG_RAW("%02x ", data[i]);
     }
-    printf("\r\n");
-    printf("read len:%d\r\n", read_byte);
+    USB_LOG_RAW("\r\n");
+    USB_LOG_RAW("read len:%d\r\n", read_byte);
     usbd_ep_read(ep, NULL, 0, NULL);
 }
 
 void usbd_cdc_acm_in(uint8_t ep)
 {
-    printf("in\r\n");
+    USB_LOG_RAW("in\r\n");
 }
 
 /*!< endpoint call back */
diff --git a/demo/usb_host.c b/demo/usb_host.c
index 1406718a..ae073127 100644
--- a/demo/usb_host.c
+++ b/demo/usb_host.c
@@ -11,11 +11,11 @@ void usbh_cdc_acm_callback(void *arg, int nbytes)
 
     if (nbytes > 0) {
         for (size_t i = 0; i < nbytes; i++) {
-            printf("0x%02x ", cdc_buffer[i]);
+            USB_LOG_RAW("0x%02x ", cdc_buffer[i]);
         }
     }
 
-    printf("nbytes:%d\r\n", nbytes);
+    USB_LOG_RAW("nbytes:%d\r\n", nbytes);
 }
 
 int cdc_acm_test(void)
@@ -25,30 +25,30 @@ int cdc_acm_test(void)
     struct usbh_cdc_acm *cdc_acm_class = (struct usbh_cdc_acm *)usbh_find_class_instance("/dev/ttyACM0");
 
     if (cdc_acm_class == NULL) {
-        printf("do not find /dev/ttyACM0\r\n");
+        USB_LOG_RAW("do not find /dev/ttyACM0\r\n");
         return -1;
     }
 
     memset(cdc_buffer, 0, 512);
     ret = usbh_ep_bulk_transfer(cdc_acm_class->bulkin, cdc_buffer, 512, 3000);
     if (ret < 0) {
-        printf("bulk in error,ret:%d\r\n", ret);
+        USB_LOG_RAW("bulk in error,ret:%d\r\n", ret);
     } else {
-        printf("recv over:%d\r\n", ret);
+        USB_LOG_RAW("recv over:%d\r\n", ret);
         for (size_t i = 0; i < ret; i++) {
-            printf("0x%02x ", cdc_buffer[i]);
+            USB_LOG_RAW("0x%02x ", cdc_buffer[i]);
         }
     }
 
-    printf("\r\n");
+    USB_LOG_RAW("\r\n");
     const uint8_t data1[10] = { 0x02, 0x00, 0x00, 0x00, 0x02, 0x02, 0x08, 0x14 };
 
     memcpy(cdc_buffer, data1, 8);
     ret = usbh_ep_bulk_transfer(cdc_acm_class->bulkout, cdc_buffer, 8, 3000);
     if (ret < 0) {
-        printf("bulk out error,ret:%d\r\n", ret);
+        USB_LOG_RAW("bulk out error,ret:%d\r\n", ret);
     } else {
-        printf("send over:%d\r\n", ret);
+        USB_LOG_RAW("send over:%d\r\n", ret);
     }
 
 #if 0
@@ -56,15 +56,15 @@ int cdc_acm_test(void)
 #else
     ret = usbh_ep_bulk_transfer(cdc_acm_class->bulkin, cdc_buffer, 512, 3000);
     if (ret < 0) {
-        printf("bulk in error,ret:%d\r\n", ret);
+        USB_LOG_RAW("bulk in error,ret:%d\r\n", ret);
     } else {
-        printf("recv over:%d\r\n", ret);
+        USB_LOG_RAW("recv over:%d\r\n", ret);
         for (size_t i = 0; i < ret; i++) {
-            printf("0x%02x ", cdc_buffer[i]);
+            USB_LOG_RAW("0x%02x ", cdc_buffer[i]);
         }
     }
 
-    printf("\r\n");
+    USB_LOG_RAW("\r\n");
 
     return ret;
 #endif
@@ -80,23 +80,23 @@ int msc_test(void)
     int ret;
     struct usbh_msc *msc_class = (struct usbh_msc *)usbh_find_class_instance("/dev/sda");
     if (msc_class == NULL) {
-        printf("do not find /dev/sda\r\n");
+        USB_LOG_RAW("do not find /dev/sda\r\n");
         return -1;
     }
 #if 1
     /* get the partition table */
     ret = usbh_msc_scsi_read10(msc_class, 0, partition_table, 1);
     if (ret < 0) {
-        printf("scsi_read10 error,ret:%d\r\n", ret);
+        USB_LOG_RAW("scsi_read10 error,ret:%d\r\n", ret);
         return ret;
     }
     for (uint32_t i = 0; i < 512; i++) {
         if (i % 16 == 0) {
-            printf("\r\n");
+            USB_LOG_RAW("\r\n");
         }
-        printf("%02x ", partition_table[i]);
+        USB_LOG_RAW("%02x ", partition_table[i]);
     }
-    printf("\r\n");
+    USB_LOG_RAW("\r\n");
 #endif
 
 #if 0
@@ -105,11 +105,11 @@ int msc_test(void)
     usb_iofree(msc_buffer);
     // for (uint32_t i = 0; i < 1024; i++) {
     //     if (i % 16 == 0) {
-    //         printf("\r\n");
+    //         USB_LOG_RAW("\r\n");
     //     }
-    //     printf("%02x ", msc_buffer[i]);
+    //     USB_LOG_RAW("%02x ", msc_buffer[i]);
     // }
-    // printf("\r\n");
+    // USB_LOG_RAW("\r\n");
 #endif
 
 #if 0
@@ -127,16 +127,16 @@ int msc_test(void)
         res_sd = f_read(&fnew, ReadBuffer, 512, &fnum);
         for (uint32_t i = 0; i < fnum; i++) {
             if (i % 16 == 0) {
-                printf("\r\n");
+                USB_LOG_RAW("\r\n");
             }
-            printf("%02x ", ReadBuffer[i]);
+            USB_LOG_RAW("%02x ", ReadBuffer[i]);
         }
-        printf("\r\n");
+        USB_LOG_RAW("\r\n");
         f_close(&fnew);
         /*unmount*/
         f_mount(NULL, "2:", 1);
     } else {
-        printf("open error:%d\r\n", res_sd);
+        USB_LOG_RAW("open error:%d\r\n", res_sd);
     }
     usb_iofree(ReadBuffer);
 #endif
@@ -151,11 +151,11 @@ void usbh_hid_callback(void *arg, int nbytes)
 
     if (nbytes > 0) {
         for (size_t i = 0; i < nbytes; i++) {
-            printf("0x%02x ", hid_buffer[i]);
+            USB_LOG_RAW("0x%02x ", hid_buffer[i]);
         }
     }
 
-    printf("nbytes:%d\r\n", nbytes);
+    USB_LOG_RAW("nbytes:%d\r\n", nbytes);
 }
 
 int hid_test(void)
@@ -163,20 +163,20 @@ int hid_test(void)
     int ret;
     struct usbh_hid *hid_class = (struct usbh_hid *)usbh_find_class_instance("/dev/input0");
     if (hid_class == NULL) {
-        printf("do not find /dev/input0\r\n");
+        USB_LOG_RAW("do not find /dev/input0\r\n");
         return -1;
     }
 #if 1
     ret = usbh_ep_intr_async_transfer(hid_class->intin, hid_buffer, 128, usbh_hid_callback, hid_class);
     if (ret < 0) {
-        printf("intr asnyc in error,ret:%d\r\n", ret);
+        USB_LOG_RAW("intr asnyc in error,ret:%d\r\n", ret);
     }
 #else
     ret = usbh_ep_intr_transfer(hid_class->intin, hid_buffer, 128, 1000);
     if (ret < 0) {
         return ret;
     }
-    printf("recv len:%d\r\n", ret);
+    USB_LOG_RAW("recv len:%d\r\n", ret);
 #endif
     return ret;
 }
\ No newline at end of file
diff --git a/demo/video_hs_mjpeg_template.c b/demo/video_hs_mjpeg_template.c
index e459acbd..68df3879 100644
--- a/demo/video_hs_mjpeg_template.c
+++ b/demo/video_hs_mjpeg_template.c
@@ -134,11 +134,11 @@ volatile bool tx_flag = 0;
 void usbd_video_open(uint8_t intf)
 {
     tx_flag = 1;
-    MSG("OPEN\r\n");
+    USB_LOG_RAW("OPEN\r\n");
 }
 void usbd_video_close(uint8_t intf)
 {
-    MSG("CLOSE\r\n");
+    USB_LOG_RAW("CLOSE\r\n");
     tx_flag = 0;
 }