diff --git a/scanner/pages/camera/camera.js b/scanner/pages/camera/camera.js
index 80bd04a..5cfa5dd 100644
--- a/scanner/pages/camera/camera.js
+++ b/scanner/pages/camera/camera.js
@@ -33,6 +33,7 @@ Page({
     phone_model: "unknown",
     progress: 0,
     zoom: -1,
+    rule_zoom: -1,
     max_zoom: 1,
     use_worker: false,
     show_tip: false,
@@ -42,6 +43,9 @@ Page({
     should_check_auto_torch: true,
     done_checking_auto_torch: false,
     camera_sensitivity: 1,
+    frame_uploaded: 0,
+    last_frame_upload_time: 0,
+    frame_upload_seq_num: 0,
   },
 
   make_hint_text(r) {
@@ -53,6 +57,10 @@ Page({
       }
     }
     if (qr_is_valid) {
+      if (this.on_qr_found) {
+        this.on_qr_found();
+        this.on_qr_found = null;
+      }
       var err = r.err || "";
       if (err.includes("margin too small")) {
         return "对齐定位点";
@@ -71,12 +79,18 @@ Page({
   },
 
   onLoad(options) {
+    var new_session_id = Date.now();
+    getApp().globalData.session_id = new_session_id;
+    if (options.env == 'dev') {
+      console.log("Using dev env settings.");
+      getApp().globalData.server_url = 'https://dev.themblem.com';
+    }
     this.log("camera page load (build240622.2120)");
     get_camera_rule(null, () => {});
     this.log("options", options);
     options = options || {};
     if (options.debug || options.scene == 'debug') {
-      getApp().globalData.debug = true;
+      getApp().globalData.debug = true
     }
     var enable_debug = getApp().globalData.debug;
     const si = get_system_info();
@@ -309,12 +323,21 @@ Page({
     }
     get_camera_rule(max_zoom, (rule) => {
       var zoom = rule.zoom;
+      var initial_zoom = 2;
       this.setData({
-        zoom,
+        zoom: initial_zoom,
+        rule_zoom: zoom,
       });
       const ctx = wx.createCameraContext();
-      this.log("camera set zoom", zoom);
-      ctx.setZoom({ zoom });
+      this.log(`camera set initial zoom to ${initial_zoom}x, will zoom in to ${rule.zoom}x when qr is found`);
+      ctx.setZoom({ zoom: initial_zoom });
+      this.on_qr_found = () => {
+        this.log(`qr found, zoom to ${rule.zoom}x`);
+        ctx.setZoom({ zoom: rule.zoom });
+        this.setData({
+          zoom: rule.zoom,
+        });
+      }
       if (!this.listener) {
         this.log("creating camera frame listener...");
         const listener = ctx.onCameraFrame((res) => { this.handle_frame(res) });
@@ -336,6 +359,36 @@ Page({
       this.failed = true;
     }
   },
+  handle_image_data_url(data_url) {
+    const now = Date.now();
+    const interval = 5000; // 5 seconds
+    if (now - this.data.last_frame_upload_time < interval) {
+      return;
+    }
+    this.setData({
+      last_frame_upload_time: now,
+      frame_upload_seq_num: this.data.frame_upload_seq_num + 1,
+    });
+    var fd = {
+      session_id: getApp().globalData.session_id,
+      phone_model: getApp().globalData.phone_model,
+      seq_num: this.data.frame_upload_seq_num,
+      image_data_url: data_url,
+    }
+    wx.request({
+      url: getApp().globalData.server_url + '/api/v1/camera-frame/',
+      method: "POST",
+      data: fd,
+      success: (res) => {
+        this.setData({
+          frame_uploaded: this.data.frame_uploaded + 1,
+        });
+      },
+      fail: (e) => {
+        this.log("frame upload failed", e);
+      },
+    });
+  },
   do_handle_frame(res) {
     if (this.busy) return;
     this.busy = true;
@@ -361,6 +414,7 @@ Page({
         result: JSON.stringify(r.result),
         debug_image_data_url: r.data_url,
       });
+      this.handle_image_data_url(data_url);
       if (this.data.done_checking_auto_torch && result.ok && result.angle >= 0 && result.qrcode.length && is_emblem_qr_pattern(result.qrcode)) {
         this.setData({
           show_modal: "verifying",
diff --git a/scanner/pages/camera/camera.wxml b/scanner/pages/camera/camera.wxml
index baa9959..097dda4 100644
--- a/scanner/pages/camera/camera.wxml
+++ b/scanner/pages/camera/camera.wxml
@@ -33,6 +33,7 @@
         <view>model: {{ phone_model }}</view>
         <view>zoom: {{ zoom }}</view>
         <view>sensitivity: {{ camera_sensitivity }}</view>
+        <view>frame uploaded: {{ frame_uploaded }}</view>
         <view>max zoom: {{ max_zoom }}</view>
         <view>result: {{ result }}</view>
     </view>