BLE test web page

olegv142 · Apr 29, 2024 · e323350 · e323350
1 parent 35c4692
commit e323350
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diff --git a/www/css/test.css b/www/css/test.css
@@ -0,0 +1,15 @@
+body {
+	font-family: sans-serif;
+}
+
+table {
+	border: 0;
+}
+
+td {
+	padding: .1em;
+}
+
+textarea {
+	width: 100%;
+}
diff --git a/www/favicon.ico b/www/favicon.ico
diff --git a/www/index.html b/www/index.html
@@ -0,0 +1,28 @@
+<!doctype html>
+<html lang="en">
+  <head>
+    <title>BLE test</title>
+    <link rel="icon" href="favicon.ico"/>
+    <meta charset="utf-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1">
+    <meta name="description" content="BLE test">
+    <link href="css/test.css" rel="stylesheet">
+  </head>
+<body>
+  <table>
+  <tr>
+  <td colspan="2"><button type="button" id="bt-btn">Connect</button></td>
+  </tr>
+  <tr>
+  <td colspan="2"><textarea id="rx-msg" rows="32" cols="32" disabled="true" readonly></textarea></td>
+  </tr>
+  <tr>
+  <td>chunks tot/bad:</td><td>msgs tot/bad:</td>
+  </tr>
+  <tr>
+  <td id="chunks">0 / 0</td><td id="msgs">0 / 0</td>
+  </tr>
+  </table>
+  <script src="js/test.js"></script>
+</body>
+</html>
diff --git a/www/js/test.js b/www/js/test.js
@@ -0,0 +1,193 @@
+'use strict';
+
+(() => {
+
+const bt_btn = document.getElementById('bt-btn');
+const rx_msg = document.getElementById('rx-msg');
+const chunks = document.getElementById('chunks');
+const msgs   = document.getElementById('msgs');
+const rx_msg_max = parseInt(rx_msg.getAttribute('rows'));
+
+const bt_svc_id  = 0xFFE0;
+const bt_char_id = 0xFFE1;
+
+let total_chunks = 0;
+let bad_chunks   = 0;
+let total_msgs   = 0;
+let bad_msgs     = 0;
+
+let bt_char    = null;
+let rx_msgs    = [];
+let last_tag   = null;
+let msg_buff   = null;
+let msg_start  = '#';
+let msg_center = '_';
+
+function initPage()
+{
+    if (!navigator.bluetooth) {
+        document.body.innerHTML = '<div class="alert-page">The Bluetooth is not supported in this browser. Please try another one.</div>';
+        return;
+    }
+    bt_btn.onclick = onConnect;
+}
+
+function showMessage(msg)
+{
+    if (rx_msgs.length >= rx_msg_max)
+        rx_msgs.shift();
+    rx_msgs.push(msg);
+    console.log('rx:', msg);
+    rx_msg.textContent = rx_msgs.join('\n');
+}
+
+function onDisconnection(event)
+{
+    const device = event.target;
+    console.log(device.name + ' bluetooth device disconnected');
+    rx_msg.disabled = true;
+    bt_char = null;
+    connectTo(device);
+}
+
+function on_new_msg(msg)
+{
+    total_msgs += 1;
+    if (msg.length % 2) {
+        console.log('invalid message length (' + msg.length + '): ' + msg)
+        bad_msgs += 1;
+        return;
+    }
+    if (msg.slice(msg.length/2, msg.length/2+1) != msg_center) {
+        console.log('invalid message : ' + msg)
+        bad_msgs += 1;
+        return;
+    }
+    if (msg.slice(1, msg.length/2) != msg.slice(msg.length/2 + 1)) {
+        console.log('corrupt message : ' + msg)
+        bad_msgs += 1;
+        return;
+    }
+}
+
+function on_new_chunk(msg)
+{
+    const tag = msg.charCodeAt(0) - 'a'.charCodeAt(0);
+    let bad_chunk = false;
+    if (last_tag !== null) {
+        let next_tag = last_tag + 1;
+        if (next_tag > 15)
+            next_tag = 0;
+        if (tag != next_tag)
+            bad_chunk = true;
+    }
+    last_tag = tag;
+
+    if (bad_chunk) {
+        bad_chunks += 1;
+        bad_msgs += 1;
+        msg_buff = null;
+    }
+
+    let start = 1, off = 1;
+    for (;;) {
+        const i = msg.indexOf(msg_start, off);
+        if (i >= 0) {
+            if (msg_buff !== null)
+                on_new_msg(msg_buff + msg.slice(start, i));
+            msg_buff = '';
+            start = i;
+            off = i + 1;
+        } else {
+            msg_buff += msg.slice(start);
+            break;
+        }
+    }
+
+    showMessage(msg);
+    total_chunks += 1;
+
+    chunks.innerHTML = total_chunks + ' / ' + bad_chunks;
+    msgs.innerHTML   = total_msgs   + ' / ' + bad_msgs;
+}
+
+function onValueChanged(event)
+{
+    const value = event.target.value;
+    let msg = '';
+    for (let i = 0; i < value.byteLength; i++) {
+        const c = value.getUint8(i);
+        msg += String.fromCharCode(c);
+    }
+    on_new_chunk(msg);
+}
+
+function onBTConnected(device, characteristic)
+{
+    console.log(device.name, 'connected');
+    characteristic.addEventListener('characteristicvaluechanged', onValueChanged);
+    device.addEventListener('gattserverdisconnected', onDisconnection);
+    rx_msg.disabled = false;
+    bt_char = characteristic;
+}
+
+function connectTo(device)
+{
+    device.gatt.connect().
+    then((server) => {
+        console.log(device.name, 'GATT server connected, getting service...');
+        return server.getPrimaryService(bt_svc_id);
+    }).
+    then((service) => {
+        console.log(device.name, 'service found, getting characteristic...');
+        return service.getCharacteristic(bt_char_id);
+    }).
+    then((characteristic) => {
+        console.log(device.name, 'characteristic found');
+        return characteristic.startNotifications().then(
+            () => {
+                onBTConnected(device, characteristic);
+            },
+            (err) => {
+                console.log('Failed to subscribe to ' + device.name + ':', err.message);
+                return Promise.reject(err);
+            }
+        );
+    })
+    .catch((err) => {
+        console.log('Failed to connect to ' + device.name + ':', err.message);
+        setTimeout(() => { connectTo(device); }, 500);
+    });
+}
+
+function doConnect(devname)
+{
+    console.log('doConnect', devname);
+    bt_btn.disabled = true;
+    let filters = [{services: [bt_svc_id]}];
+    if (devname) {
+        filters.push({name: devname});
+    }
+    return navigator.bluetooth.requestDevice({
+        filters: filters,
+    }).
+    then((device) => {
+        console.log(device.name, 'selected');
+        connectTo(device);
+    })
+    .catch((err) => {
+        console.log('Failed to discover BT devices');
+        bt_btn.disabled = false;
+    });
+}
+
+function onConnect(event)
+{
+    console.log('onConnect');
+    doConnect();
+}
+
+initPage();
+
+})();
+