Add serial number display

src/lib/components/MoreInfo.svelte

@@ -1,17 +1,24 @@
 <script lang="ts">
   import type { PopoverTriggerProps } from 'bits-ui'
+  import type { Snippet } from 'svelte'
 
   import IconInfo from '~icons/material-symbols/info'
   import * as Popover from '$lib/components/ui/popover'
 
-  interface Props extends PopoverTriggerProps {}
+  interface Props extends PopoverTriggerProps {
+    icon?: Snippet
+  }
 
-  const { children, ...restProps }: Props = $props()
+  const { icon, children, ...restProps }: Props = $props()
 </script>
 
 <Popover.Root>
   <Popover.Trigger aria-label="More info" {...restProps}>
+    {#if !icon}
       <IconInfo class="text-muted-foreground text-sm" aria-hidden />
+    {:else}
+      {@render icon()}
+    {/if}
   </Popover.Trigger>
 
   <Popover.Content class="text-sm">

src/lib/contexts/device.svelte.ts

@@ -48,3 +48,15 @@ export function createDeviceContext(): DeviceContext {
 
   return setContext(DeviceContextToken, ctx)
 }
+
+export async function tryOpenDevice(device: HIDDevice): Promise<boolean> {
+  if (device.opened) return true
+
+  try {
+    await device.open()
+    return true
+  } catch (e) {
+    toast.error(`Unable to open device: ${e}`)
+    return false
+  }
+}

src/lib/layouts/connect/ConnectSection.svelte

@@ -3,9 +3,40 @@
   import IconCheckCircle from '~icons/material-symbols/check-circle'
   import ConnectButton from './ConnectButton.svelte'
 
-  import { getDeviceContext } from '$lib/contexts/device.svelte'
+  import { getDeviceContext, tryOpenDevice } from '$lib/contexts/device.svelte'
+  import MoreInfo from '$lib/components/MoreInfo.svelte'
 
   const deviceCtx = getDeviceContext()
+
+  let serial = $state('[Retrieving...]')
+
+  async function updateSerial() {
+    if (deviceCtx.device === null) {
+      serial = '[Retrieving...]'
+      return
+    }
+    if (!(await tryOpenDevice(deviceCtx.device))) {
+      serial = '[Error]'
+      return
+    }
+
+    function setSerial(e: HIDInputReportEvent) {
+      if (e.reportId !== 0x02) return
+      serial = String.fromCharCode(...Array.from(new Uint8Array(e.data.buffer)))
+    }
+
+    let updated = false
+    deviceCtx.device.addEventListener('inputreport', e => {
+      if (!updated) setSerial(e)
+      updated = true
+    })
+
+    deviceCtx.device.sendReport(0x02, new Uint8Array(1))
+  }
+
+  $effect(() => {
+    updateSerial()
+  })
 </script>
 
 <section class="row gap-2 max-lg:stack max-lg:items-stretch" aria-labelledby="connect-section-label">
@@ -17,8 +48,13 @@
         <IconPending aria-hidden /> Not connected to any device yet. Plug in your device, and click on the button to select
         it.
       {:else}
-        <IconCheckCircle aria-hidden /> Successfully conected to device. If you want to, you can connect to another device
-        instead.
+        <MoreInfo>
+          {#snippet icon()}
+            <IconCheckCircle aria-hidden />
+          {/snippet}
+          The serial ID of this device is <code>{serial}</code>.
+        </MoreInfo>
+        Successfully conected to device. If you want to, you can connect to another device instead.
       {/if}
     </div>
   </div>

src/lib/layouts/write/WriteButton.svelte

@@ -2,7 +2,7 @@
   import { Button } from '$lib/components/ui/button'
 
   import { toast } from 'svelte-sonner'
-  import { getDeviceContext } from '$lib/contexts/device.svelte'
+  import { getDeviceContext, tryOpenDevice } from '$lib/contexts/device.svelte'
   import { getRenderedContext } from '$lib/contexts/rendered.svelte'
   import { BYTES_IN_A_ROW, DEVICE_HEIGHT, DEVICE_WIDTH, WRITE_TIME } from '$lib/constants'
 
@@ -22,15 +22,7 @@
 
   async function connectAndWrite() {
     if (deviceCtx.device === null || renderedCtx.rendered === null) return
-
-    if (!deviceCtx.device.opened) {
-      try {
-        await deviceCtx.device.open()
-      } catch (e) {
-        toast.error(`Unable to open device: ${e}`)
-        return
-      }
-    }
+    if (!(await tryOpenDevice(deviceCtx.device))) return
 
     const buffer = new Uint8Array(DEVICE_HEIGHT * BYTES_IN_A_ROW)
     for (let y = 0; y < DEVICE_HEIGHT; y++) {
@@ -47,7 +39,7 @@
     inProgress = true
 
     try {
-      await deviceCtx.device.sendReport(0, buffer)
+      await deviceCtx.device.sendReport(0x01, buffer)
     } catch (e) {
       toast.error(`Error writing to device: ${e}`)
       return