diff --git a/package.json b/package.json
index 16470ba..b6cdea1 100644
--- a/package.json
+++ b/package.json
@@ -18,7 +18,7 @@
 		"@byteowls/capacitor-filesharer": "^6.0.0",
 		"@capacitor/core": "^6.1.2",
 		"@fontsource-variable/noto-sans": "^5.0.5",
-		"@mmote/niimbluelib": "0.0.1-alpha.21",
+		"@mmote/niimbluelib": "0.0.1-alpha.22",
 		"@popperjs/core": "^2.11.8",
 		"bootstrap": "5.3.3",
 		"d3-dsv": "^3.0.1",
diff --git a/src/index.ts b/src/index.ts
index f27e586..cfe8915 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -2,6 +2,7 @@ import "./style.scss";
 import "@popperjs/core";
 import "toastify-js/src/toastify.css";
 import "bootstrap/js/dist/dropdown";
+import "bootstrap/js/dist/collapse";
 import App from "./App.svelte";
 import { config as FabricConfig } from "fabric";
 
diff --git a/src/lib/PrinterConnector.svelte b/src/lib/PrinterConnector.svelte
index 1871525..8f3e96e 100644
--- a/src/lib/PrinterConnector.svelte
+++ b/src/lib/PrinterConnector.svelte
@@ -1,5 +1,6 @@
 <script lang="ts">
   import {
+    FirmwareProgressEvent,
     NiimbotCapacitorBleClient,
     SoundSettingsItemType,
     Utils,
@@ -24,10 +25,13 @@
   import { onMount } from "svelte";
   import { LocalStoragePersistence } from "../utils/persistence";
   import type { MaterialIcon } from "material-icons";
+  import { FileUtils } from "../utils/file_utils";
 
   let connectionType: ConnectionType = "bluetooth";
   let rfidInfo: RfidInfo | undefined = undefined;
   let featureSupport: AvailableTransports = { webBluetooth: false, webSerial: false, capacitorBle: false };
+  let fwVersion: string = "";
+  let fwProgress: string = "";
 
   const onConnectClicked = async () => {
     initClient(connectionType);
@@ -76,6 +80,34 @@
     await $printerClient.abstraction.printerReset();
   };
 
+  const upgradeFw = async () => {
+    if (!confirm("Flashing wrong firmware can make your printer dead. Are you sure?")) {
+      return;
+    }
+
+    const data = await FileUtils.pickAndReadBinaryFile("bin");
+
+    const listener = (e: FirmwareProgressEvent) => {
+      fwProgress = `${e.currentChunk}/${e.totalChunks}`;
+    };
+
+    $printerClient.stopHeartbeat();
+
+    try {
+      $printerClient.on("firmwareprogress", listener);
+      fwProgress = "...";
+      await $printerClient.abstraction.firmwareUpgrade(data, fwVersion);
+      $printerClient.off("firmwareprogress", listener);
+      await $printerClient.disconnect();
+
+      Toasts.message("Flashing is finished, the printer will shut down now");
+    } catch (e) {
+      Toasts.error(e);
+      $printerClient.startHeartbeat();
+      $printerClient.off("firmwareprogress", listener);
+    }
+  };
+
   const switchConnectionType = (c: ConnectionType) => {
     LocalStoragePersistence.saveLastConnectionType(c);
     connectionType = c;
@@ -133,8 +165,15 @@
       {/if}
 
       {#if $printerMeta}
-        <div>
-          Model metadata:
+        <button
+          class="btn btn-sm btn-outline-secondary d-block w-100 mt-1"
+          type="button"
+          data-bs-toggle="collapse"
+          data-bs-target="#modelMeta">
+          Model metadata <MdIcon icon="expand_more" />
+        </button>
+
+        <div class="collapse" id="modelMeta">
           <ul>
             {#each Object.entries($printerMeta) as [k, v]}
               <li>{k}: <strong>{v ?? "-"}</strong></li>
@@ -144,8 +183,15 @@
       {/if}
 
       {#if rfidInfo}
-        <div>
-          Rfid info:
+        <button
+          class="btn btn-sm btn-outline-secondary d-block w-100 mt-1"
+          type="button"
+          data-bs-toggle="collapse"
+          data-bs-target="#rfidInfo">
+          Rfid info <MdIcon icon="expand_more" />
+        </button>
+
+        <div class="collapse" id="rfidInfo">
           <ul>
             {#each Object.entries(rfidInfo) as [k, v]}
               <li>{k}: <strong>{v ?? "-"}</strong></li>
@@ -155,8 +201,15 @@
       {/if}
 
       {#if $heartbeatData}
-        <div>
-          Heartbeat data:
+        <button
+          class="btn btn-sm btn-outline-secondary d-block w-100 mt-1"
+          type="button"
+          data-bs-toggle="collapse"
+          data-bs-target="#heartbeatData">
+          Heartbeat data <MdIcon icon="expand_more" />
+        </button>
+
+        <div class="collapse" id="heartbeatData">
           <ul>
             {#each Object.entries($heartbeatData) as [k, v]}
               <li>{k}: <strong>{v ?? "-"}</strong></li>
@@ -165,15 +218,35 @@
         </div>
       {/if}
 
-      <div>Tests</div>
+      <div class="input-group input-group-sm mt-1">
+        {#if fwProgress}
+          <span class="input-group-text">Uploading {fwProgress}</span>
+        {:else}
+          <button class="btn btn-sm btn-primary" on:click={upgradeFw} disabled={!!fwProgress}>Upgrade FW</button>
+          <span class="input-group-text">To version</span>
+          <input class="form-control" placeholder="x.x" type="text" size="6" bind:value={fwVersion} />
+        {/if}
+      </div>
 
-      <button class="btn btn-sm btn-primary" on:click={getRfidInfo}>Rfid</button>
-      <button class="btn btn-sm btn-primary" on:click={startHeartbeat}>Heartbeat on</button>
-      <button class="btn btn-sm btn-primary" on:click={stopHeartbeat}>Heartbeat off</button>
-      <button class="btn btn-sm btn-primary" on:click={soundOn}>Sound on</button>
-      <button class="btn btn-sm btn-primary" on:click={soundOff}>Sound off</button>
-      <button class="btn btn-sm btn-primary" on:click={fetchInfo}>Fetch info again</button>
-      <button class="btn btn-sm btn-primary" on:click={reset}>Reset</button>
+      <button
+        class="btn btn-sm btn-outline-secondary d-block w-100 mt-1"
+        type="button"
+        data-bs-toggle="collapse"
+        data-bs-target="#tests">
+        Tests <MdIcon icon="expand_more" />
+      </button>
+
+      <div class="collapse" id="tests">
+        <div class="d-flex flex-wrap gap-1 mt-1">
+          <button class="btn btn-sm btn-primary" on:click={getRfidInfo}>Rfid</button>
+          <button class="btn btn-sm btn-primary" on:click={startHeartbeat}>Heartbeat on</button>
+          <button class="btn btn-sm btn-primary" on:click={stopHeartbeat}>Heartbeat off</button>
+          <button class="btn btn-sm btn-primary" on:click={soundOn}>Sound on</button>
+          <button class="btn btn-sm btn-primary" on:click={soundOff}>Sound off</button>
+          <button class="btn btn-sm btn-primary" on:click={fetchInfo}>Fetch info again</button>
+          <button class="btn btn-sm btn-primary" on:click={reset}>Reset</button>
+        </div>
+      </div>
     </div>
     <span class="input-group-text {$heartbeatFails > 0 ? 'text-warning' : ''}">
       {$printerMeta?.model ?? $connectedPrinterName}
diff --git a/src/style.scss b/src/style.scss
index a8425f2..e5d0c1f 100644
--- a/src/style.scss
+++ b/src/style.scss
@@ -11,6 +11,7 @@
 @import "bootstrap/scss/close";
 @import "bootstrap/scss/progress";
 @import "bootstrap/scss/alert";
+@import "bootstrap/scss/transitions";
 @import "font";
 
 body {
@@ -22,3 +23,9 @@ body {
   border: 1px solid var(--bs-danger-border-subtle);
   color: var(--bs-danger-text-emphasis);
 }
+
+.toastify.toast-info {
+  background: var(--bs-success-bg-subtle);
+  border: 1px solid var(--bs-success-border-subtle);
+  color: var(--bs-success-text-emphasis);
+}
diff --git a/src/utils/file_utils.ts b/src/utils/file_utils.ts
index a3b41ed..42a3d12 100644
--- a/src/utils/file_utils.ts
+++ b/src/utils/file_utils.ts
@@ -137,6 +137,44 @@ export class FileUtils {
     });
   }
 
+  /**
+   * Open file picker and return file contents
+   *
+   * fixme: never ends if dialog closed
+   *
+   * */
+  static async pickAndReadBinaryFile(acceptExtension: string): Promise<Uint8Array> {
+    return new Promise((resolve, reject) => {
+      const input: HTMLInputElement = document.createElement("input");
+      const reader = new FileReader();
+
+      input.type = "file";
+      input.accept = `.${acceptExtension}`;
+
+      input.onchange = (e: Event) => {
+        const target = e.target as HTMLInputElement;
+        if (target.files !== null) {
+          const file: File = target.files[0];
+          const ext = file.name.split(".").pop();
+
+          if (ext === acceptExtension) {
+            reader.readAsArrayBuffer(file);
+            reader.onload = (readerEvt: ProgressEvent<FileReader>) => {
+              if (readerEvt?.target?.result) {
+                resolve(new Uint8Array(readerEvt.target.result as ArrayBuffer));
+              }
+            };
+            reader.onerror = (readerEvt: ProgressEvent<FileReader>) => {
+              console.error(readerEvt);
+              reject(new Error("Unable to load file"));
+            };
+          }
+        }
+      };
+      input.click();
+    });
+  }
+
   static async loadCanvasState(canvas: fabric.Canvas, state: FabricJson): Promise<void> {
     await canvas.loadFromJSON(state, (_, obj) => {
       if ("set" in obj) obj.set({ snapAngle: OBJECT_DEFAULTS.snapAngle });
diff --git a/src/utils/toasts.ts b/src/utils/toasts.ts
index c1aa516..462be96 100644
--- a/src/utils/toasts.ts
+++ b/src/utils/toasts.ts
@@ -13,6 +13,15 @@ export class Toasts {
     }).showToast();
   }
 
+  static message(text: string) {
+    Toastify({
+      text,
+      gravity: "bottom",
+      duration: 5000,
+      className: "toast-info",
+    }).showToast();
+  }
+
   static zodErrors(e: any, prefix: string) {
     if (e instanceof z.ZodError) {
       e.issues.forEach((i) => {
diff --git a/yarn.lock b/yarn.lock
index d1e0a58..fb2294d 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -183,14 +183,15 @@
     "@jridgewell/resolve-uri" "^3.1.0"
     "@jridgewell/sourcemap-codec" "^1.4.14"
 
-"@mmote/niimbluelib@0.0.1-alpha.21":
-  version "0.0.1-alpha.21"
-  resolved "https://registry.yarnpkg.com/@mmote/niimbluelib/-/niimbluelib-0.0.1-alpha.21.tgz#35b2c31094070c69aec4663521ce64475662ebfb"
-  integrity sha512-wSJ1d7VgLwl6G71DOmKITX7XX1OypZaPNim+Aa2Dpa6nyifo1v8WrYOr4aKGGJzZt1oSxQ+spWv2thsQrX2Baw==
+"@mmote/niimbluelib@0.0.1-alpha.22":
+  version "0.0.1-alpha.22"
+  resolved "https://registry.yarnpkg.com/@mmote/niimbluelib/-/niimbluelib-0.0.1-alpha.22.tgz#34ee209616dcf3988a063eb154d83251315928d6"
+  integrity sha512-XsD9DyyD7RaNlZwqZinLopFy6knjov1JU4nnrA9iqJ4Tdv5sDu6WFHdUKR8Ip8+fkJ7sBF6UHi7y+Ucc4A5wIg==
   dependencies:
     "@capacitor-community/bluetooth-le" "^6.0.2"
     "@capacitor/core" "^6.0.0"
     async-mutex "^0.5.0"
+    crc-32 "^1.2.2"
     eventemitter3 "^5.0.1"
 
 "@popperjs/core@^2.11.8", "@popperjs/core@^2.9.2":
@@ -507,6 +508,11 @@ concat-map@0.0.1:
   resolved "https://registry.yarnpkg.com/concat-map/-/concat-map-0.0.1.tgz#d8a96bd77fd68df7793a73036a3ba0d5405d477b"
   integrity sha512-/Srv4dswyQNBfohGpz9o6Yb3Gz3SrUDqBH5rTuhGR7ahtlbYKnVxw2bCFMRljaA7EXHaXZ8wsHdodFvbkhKmqg==
 
+crc-32@^1.2.2:
+  version "1.2.2"
+  resolved "https://registry.yarnpkg.com/crc-32/-/crc-32-1.2.2.tgz#3cad35a934b8bf71f25ca524b6da51fb7eace2ff"
+  integrity sha512-ROmzCKrTnOwybPcJApAA6WBWij23HVfGVNKqqrZpuyZOHqK2CwHSvpGuyt/UNNvaIjEd8X5IFGp4Mh+Ie1IHJQ==
+
 css-tree@^2.3.1:
   version "2.3.1"
   resolved "https://registry.yarnpkg.com/css-tree/-/css-tree-2.3.1.tgz#10264ce1e5442e8572fc82fbe490644ff54b5c20"