diff --git a/main/main.c b/main/main.c
index 29863a2..c7a0db3 100644
--- a/main/main.c
+++ b/main/main.c
@@ -160,35 +160,46 @@ static void post_data(camera_fb_t * pic){
       return;
    }
 
+   // the empty body of the header, must be sent to complete the message
    sprintf(tmpStr, "\r\n");
    esp_http_client_write(client, tmpStr, strlen(tmpStr));
 
+   // wait a bit for response, expecting code 100
    vTaskDelay(10 / portTICK_RATE_MS);
    esp_http_client_fetch_headers(client);
-   ESP_LOGI(TAG, "code %d", esp_http_client_get_status_code(client));
+   int http_status_code = esp_http_client_get_status_code(client);
 
-   // send head
+   if (http_status_code != 100) {
+      ESP_LOGE(TAG, "Expecting HTTP status code 100, received: %u", http_status_code);
+      return;
+   }
+   else {
+      ESP_LOGI(TAG, "HTTP status code %d, continue sending data ...", http_status_code);
+   }
+
+   // got 100, proceed to send head
    esp_http_client_write(client, head, strlen(head));
-   ESP_LOGI(TAG, "%s", (char *)head);
+   ESP_LOGI(TAG, "head: %s", (char *)head);
 
+   // data in chunks
    size_t nChunks = pic->len / CHUNK_SIZE + 1;
 
    uint8_t *ptr = pic->buf;
    size_t fbLen = pic->len;
-   ESP_LOGI(TAG, "photo size 0x%x, will be posted in %u chunks", fbLen, nChunks);
+   ESP_LOGI(TAG, "photo size %u bytes, will be posted in %u chunks", fbLen, nChunks);
 
    for (size_t n = 0; n < fbLen; n += CHUNK_SIZE) {
       if (n + CHUNK_SIZE < fbLen) {
          esp_http_client_write(client, (char *)ptr, CHUNK_SIZE);
-         if (n<2) {
-            sprintf(tmpStr, "%u:", n);
-            for (int i = 0; i < 15; i++) {
-               char nextChar[4];
-               sprintf(nextChar, "%x", ptr[i]);
-               strcat(tmpStr, nextChar);
-            }
-            ESP_LOGI(TAG, "%.16s", tmpStr);
-         }
+         //if (n<2) {
+         //   sprintf(tmpStr, "%u:", n);
+         //   for (int i = 0; i < 15; i++) {
+         //      char nextChar[4];
+         //      sprintf(nextChar, "%x", ptr[i]);
+         //      strcat(tmpStr, nextChar);
+         //   }
+         //   ESP_LOGI(TAG, "%.16s", tmpStr);
+         //}
          ptr += CHUNK_SIZE;
       }
       else if (fbLen % CHUNK_SIZE > 0){
@@ -196,10 +207,18 @@ static void post_data(camera_fb_t * pic){
       }
    }
 
-   ESP_LOGI(TAG, "%s", (char *)tail);
+   // and the tail
+   ESP_LOGI(TAG, "tail: %s", (char *)tail);
    esp_http_client_write(client, tail, strlen(tail));
-   esp_http_client_fetch_headers(client);
-   ESP_LOGI(TAG, "response %d", esp_http_client_get_status_code(client));
+
+   // check HTTP response
+   int response_length = esp_http_client_fetch_headers(client);
+   http_status_code = esp_http_client_get_status_code(client);
+   ESP_LOGI(TAG, "HTTP status: %d, content-length: %d", http_status_code, response_length);
+   if (response_length > 0 && response_length < CHUNK_SIZE) {
+      esp_http_client_read(client, tmpStr, response_length);
+      ESP_LOGI(TAG, "HTTP response: %s", tmpStr);
+   }
 
    esp_http_client_cleanup(client);
 }