diff --git a/scanner/pages/frame/frame.js b/scanner/pages/frame/frame.js
index df27d65..a3b9d6d 100644
--- a/scanner/pages/frame/frame.js
+++ b/scanner/pages/frame/frame.js
@@ -10,7 +10,7 @@ Page({
     data: {
         uploaded: 0,
         failed: 0,
-        session_id: Date.now(),
+        session_id: null,
         frame_id: 0,
         next_upload_time: 0,
         uploading: false,
@@ -73,20 +73,24 @@ Page({
     },
 
     set_pos() {
+        const session_id = new Date().toISOString() + "_pos";
         this.setData({
             label: "pos",
             pos_class: "active",
             neg_class: "",
             stop_class: "",
+            session_id,
         })
     },
     
     set_neg() {
+        const session_id = new Date().toISOString() + "_neg";
         this.setData({
             label: "neg",
             pos_class: "",
             neg_class: "active",
             stop_class: "",
+            session_id,
         })
     },
     stop() {
@@ -105,6 +109,7 @@ Page({
         })
         const listener = ctx.onCameraFrame((res) => { this.handle_frame(res) });
         listener.start();
+        this.ctx = ctx;
     },
     handle_frame(res) {
         if (!this.data.label || this.data.uploading) {
@@ -150,4 +155,19 @@ Page({
             },
         });
     },
+    zoom_1x() {
+        this.ctx.setZoom({
+            zoom: 1,
+        });
+    },
+    zoom_2x() {
+        this.ctx.setZoom({
+            zoom: 2,
+        });
+    },
+    zoom_4x() {
+        this.ctx.setZoom({
+            zoom: 4,
+        });
+    },
 })
\ No newline at end of file
diff --git a/scanner/pages/frame/frame.wxml b/scanner/pages/frame/frame.wxml
index 51d1423..edf66dd 100644
--- a/scanner/pages/frame/frame.wxml
+++ b/scanner/pages/frame/frame.wxml
@@ -3,6 +3,9 @@
     <button class="{{pos_class}}" bind:tap="set_pos">Pos</button>
     <button class="{{neg_class}}" bind:tap="set_neg">Neg</button>
     <button class="{{stop_class}}" bind:tap="stop">Stop</button>
+    <button bind:tap="zoom_1x">1x</button>
+    <button bind:tap="zoom_2x">2x</button>
+    <button bind:tap="zoom_4x">4x</button>
     <view>
         uploaded: {{ uploaded }}
         failed: {{ failed }}