From 8f53e9b849daebfaa6d37f7e7f50ecea28ef0d7b Mon Sep 17 00:00:00 2001
From: liamcottle <liam@liamcottle.com>
Date: Tue, 11 Feb 2025 21:39:18 +1300
Subject: [PATCH] implement ble connection and tidy up classes

---
 index.html                                  |  59 ++++---
 src/connection/ble_connection.js            |  95 +++++++++++
 src/{device.js => connection/connection.js} | 149 +-----------------
 src/connection/serial_connection.js         | 165 ++++++++++++++++++++
 src/constants.js                            |   8 +-
 5 files changed, 301 insertions(+), 175 deletions(-)
 create mode 100644 src/connection/ble_connection.js
 rename src/{device.js => connection/connection.js} (65%)
 create mode 100644 src/connection/serial_connection.js

diff --git a/index.html b/index.html
index 4ac9f1e..36e64fe 100644
--- a/index.html
+++ b/index.html
@@ -15,7 +15,7 @@
     <!-- header -->
     <div class="flex border bg-gray-50 p-3 rounded shadow">
         <div class="my-auto">
-            <div class="font-bold">MeshCore Client</div>
+            <div class="font-bold">MeshCore Connection</div>
             <div class="text-sm">Developed by <a target="_blank" href="https://liamcottle.com" class="text-blue-500 hover:underline">Liam Cottle</a></div>
         </div>
     </div>
@@ -24,7 +24,10 @@
 
         <div class="p-3 border-t space-x-1">
             <button @click="askForSerialPort" class="border border-gray-500 px-2 bg-gray-100 hover:bg-gray-200 rounded">
-                Connect
+                Connect (Serial)
+            </button>
+            <button @click="askForBleDevice" class="border border-gray-500 px-2 bg-gray-100 hover:bg-gray-200 rounded">
+                Connect (BLE)
             </button>
             <button @click="disconnect" class="border border-gray-500 px-2 bg-gray-100 hover:bg-gray-200 rounded">
                 Disconnect
@@ -81,8 +84,9 @@
 </div>
 
 <script type="module">
-    import Device from "./src/device.js";
     import Constants from "./src/constants.js";
+    import SerialConnection from "./src/connection/serial_connection.js";
+    import BleConnection from "./src/connection/ble_connection.js";
     Vue.createApp({
         data() {
             return {
@@ -94,28 +98,19 @@
         },
         methods: {
             async askForSerialPort() {
-
-                if(!navigator.serial){
-                    alert("Web Serial is not supported in this browser");
-                    return null;
-                }
-
-                // ask user to select device
-                const serialPort = await navigator.serial.requestPort({
-                    filters: [],
-                });
-
-                this.device = await Device.fromSerialPort(serialPort);
-
+                this.connection = await SerialConnection.open();
+            },
+            async askForBleDevice() {
+                this.connection = await BleConnection.open();
             },
             async disconnect() {
-                if(this.device){
-                    await this.device.close();
+                if(this.connection){
+                    await this.connection.close();
                     this.device = null;
                 }
             },
             async sendCommandAppStart() {
-                await this.device.sendCommandAppStart();
+                await this.connection.sendCommandAppStart();
             },
             async sendCommandSendTxtMsg() {
                 const txtType = Constants.TxtTypes.Plain;
@@ -123,35 +118,35 @@
                 const senderTimestamp = Math.floor(Date.now() / 1000);
                 const pubKeyPrefix = new Uint8Array([148, 63, 175, 162, 88, 212, 192, 40, 214, 185, 213, 140, 42, 145, 194, 186, 70, 71, 112, 68, 0, 192, 65, 4, 105, 143, 230, 50, 162, 79, 247, 192]);
                 const text = `Test Message: ${senderTimestamp}`;
-                await this.device.sendCommandSendTxtMsg(txtType, attempt, senderTimestamp, pubKeyPrefix, text);
+                await this.connection.sendCommandSendTxtMsg(txtType, attempt, senderTimestamp, pubKeyPrefix, text);
             },
             async sendSendSelfAdvert(type) {
-                await this.device.sendCommandSendSelfAdvert(type);
+                await this.connection.sendCommandSendSelfAdvert(type);
             },
             async sendCommandGetContacts() {
-                await this.device.sendCommandGetContacts();
+                await this.connection.sendCommandGetContacts();
             },
             async sendCommandGetDeviceTime() {
-                await this.device.sendCommandGetDeviceTime();
+                await this.connection.sendCommandGetDeviceTime();
             },
             async sendCommandSetDeviceTime() {
                 const timestamp = Math.floor(Date.now() / 1000);
-                await this.device.sendCommandSetDeviceTime(timestamp);
+                await this.connection.sendCommandSetDeviceTime(timestamp);
             },
             async sendCommandSetTxPower() {
                 const txPower = 22;
-                await this.device.sendCommandSetTxPower(txPower);
+                await this.connection.sendCommandSetTxPower(txPower);
             },
             async sendCommandResetPath() {
                 const publicKey = new Uint8Array([244, 231, 60, 250, 245, 218, 131, 156, 156, 98, 130, 39, 222, 43, 123, 147, 98, 200, 218, 251, 242, 89, 111, 108, 25, 191, 127, 151, 222, 192, 233, 177]);
-                await this.device.sendCommandResetPath(publicKey);
+                await this.connection.sendCommandResetPath(publicKey);
             },
             async sendCommandSetRadioParams() {
                 const radioFreq = 917375;
                 const radioBw = 250000;
                 const radioSf = 7;
                 const radioCr = 5;
-                await this.device.sendCommandSetRadioParams(radioFreq, radioBw, radioSf, radioCr);
+                await this.connection.sendCommandSetRadioParams(radioFreq, radioBw, radioSf, radioCr);
             },
             async sendCommandSetAdvertName() {
 
@@ -162,17 +157,17 @@
                 }
 
                 // set name
-                await this.device.sendCommandSetAdvertName(name);
+                await this.connection.sendCommandSetAdvertName(name);
 
             },
             async sendCommandSetAdvertLatLon() {
                 const lat = 123;
                 const lon = 456;
-                await this.device.sendCommandSetAdvertLatLon(lat, lon);
+                await this.connection.sendCommandSetAdvertLatLon(lat, lon);
             },
             async sendCommandRemoveContact() {
                 const publicKey = new Uint8Array([148, 63, 175, 162, 88, 212, 192, 40, 214, 185, 213, 140, 42, 145, 194, 186, 70, 71, 112, 68, 0, 192, 65, 4, 105, 143, 230, 50, 162, 79, 247, 192]);
-                await this.device.sendCommandRemoveContact(publicKey);
+                await this.connection.sendCommandRemoveContact(publicKey);
             },
             async sendCommandAddUpdateContact() {
                 const publicKey = new Uint8Array([148, 63, 175, 162, 88, 212, 192, 40, 214, 185, 213, 140, 42, 145, 194, 186, 70, 71, 112, 68, 0, 192, 65, 4, 105, 143, 230, 50, 162, 79, 247, 192]);
@@ -184,10 +179,10 @@
                 const lastAdvert = 1739244825;
                 const advLat = 0;
                 const advLon = 0;
-                await this.device.sendCommandAddUpdateContact(publicKey, type, flags, outPathLen, outPath, advName, lastAdvert, advLat, advLon);
+                await this.connection.sendCommandAddUpdateContact(publicKey, type, flags, outPathLen, outPath, advName, lastAdvert, advLat, advLon);
             },
             async sendCommandSyncNextMessage() {
-                await this.device.sendCommandSyncNextMessage();
+                await this.connection.sendCommandSyncNextMessage();
             },
         },
     }).mount('#app');
diff --git a/src/connection/ble_connection.js b/src/connection/ble_connection.js
new file mode 100644
index 0000000..c62df05
--- /dev/null
+++ b/src/connection/ble_connection.js
@@ -0,0 +1,95 @@
+import Constants from "../constants.js";
+import Connection from "./connection.js";
+
+class BleConnection extends Connection {
+
+    constructor(bleDevice) {
+        super();
+        this.bleDevice = bleDevice;
+        this.gattServer = null;
+        this.rxCharacteristic = null;
+        this.txCharacteristic = null;
+        this.init();
+    }
+
+    static async open() {
+
+        // ensure browser supports web bluetooth
+        if(!navigator.bluetooth){
+            alert("Web Bluetooth is not supported in this browser");
+            return;
+        }
+
+        // ask user to select device
+        const device = await navigator.bluetooth.requestDevice({
+            filters: [
+                {
+                    services: [
+                        Constants.Ble.ServiceUuid.toLowerCase(),
+                    ],
+                },
+            ],
+        });
+
+        // make sure user selected a device
+        if(!device){
+            return null;
+        }
+
+        return new BleConnection(device);
+
+    }
+
+    async init() {
+
+        // connect to gatt server
+        this.gattServer = await this.bleDevice.gatt.connect();
+
+        // find service
+        const service = await this.gattServer.getPrimaryService(Constants.Ble.ServiceUuid.toLowerCase());
+        const characteristics = await service.getCharacteristics();
+
+        // find rx characteristic (we write to this one, it's where the radio reads from)
+        this.rxCharacteristic = characteristics.find((characteristic) => {
+            return characteristic.uuid.toLowerCase() === Constants.Ble.CharacteristicUuidRx.toLowerCase();
+        });
+
+        // find tx characteristic (we read this one, it's where the radio writes to)
+        this.txCharacteristic = characteristics.find((characteristic) => {
+            return characteristic.uuid.toLowerCase() === Constants.Ble.CharacteristicUuidTx.toLowerCase();
+        });
+
+        // listen for frames from transmitted to us from the ble device
+        await this.txCharacteristic.startNotifications();
+        this.txCharacteristic.addEventListener('characteristicvaluechanged', (event) => {
+            const frame = new Uint8Array(event.target.value.buffer);
+            this.onFrameReceived(frame);
+        });
+
+    }
+
+    async close() {
+        try {
+            this.gattServer?.disconnect();
+            this.gattServer = null;
+        } catch(e) {
+            // ignore error when disconnecting
+        }
+    }
+
+    async write(bytes) {
+        try {
+            // we write to the rx characteristic, as that's where the radio reads from
+            await this.rxCharacteristic.writeValue(bytes);
+        } catch(e) {
+            console.log("failed to write to ble device", e);
+        }
+    }
+
+    async sendToRadioFrame(data) {
+        await this.write(data);
+    }
+
+}
+
+export default BleConnection;
diff --git a/src/device.js b/src/connection/connection.js
similarity index 65%
rename from src/device.js
rename to src/connection/connection.js
index 328616a..eb95f3c 100644
--- a/src/device.js
+++ b/src/connection/connection.js
@@ -1,75 +1,15 @@
-import BufferWriter from "./buffer_writer.js";
-import BufferReader from "./buffer_reader.js";
-import Constants from "./constants.js";
+import BufferWriter from "../buffer_writer.js";
+import BufferReader from "../buffer_reader.js";
+import Constants from "../constants.js";
 
-class Device {
-
-    constructor(serialPort) {
-        this.serialPort = serialPort;
-        this.reader = serialPort.readable.getReader();
-        this.writable = serialPort.writable;
-        this.readBuffer = [];
-        this.readLoop();
-    }
-
-    static async fromSerialPort(serialPort) {
-
-        // open port
-        await serialPort.open({
-            baudRate: 115200,
-        });
-
-        return new Device(serialPort);
-
-    }
+class Connection {
 
     async close() {
-
-        // release reader lock
-        try {
-            this.reader.releaseLock();
-        } catch(e) {
-            // console.log("failed to release lock on serial port readable, ignoring...", e);
-        }
-
-        // close serial port
-        try {
-            await this.serialPort.close();
-        } catch(e) {
-            // console.log("failed to close serial port, ignoring...", e);
-        }
-
-    }
-
-    async write(bytes) {
-        const writer = this.writable.getWriter();
-        try {
-            await writer.write(new Uint8Array(bytes));
-        } finally {
-            writer.releaseLock();
-        }
-    }
-
-    async writeFrame(frameType, frameData) {
-
-        // create frame
-        const frame = new BufferWriter();
-
-        // add frame header
-        frame.writeByte(frameType);
-        frame.writeUInt16LE(frameData.length);
-
-        // add frame data
-        frame.writeBytes(frameData);
-
-        // write frame to device
-        await this.write(frame.toBytes());
-
+        throw new Error("This method must be implemented by the subclass.");
     }
 
     async sendToRadioFrame(data) {
-        // write "app to radio" frame 0x3c "<"
-        await this.writeFrame(0x3c, data);
+        throw new Error("This method must be implemented by the subclass.");
     }
 
     async sendCommandAppStart() {
@@ -188,81 +128,6 @@ class Device {
         await this.sendToRadioFrame(data.toBytes());
     }
 
-    async readLoop() {
-        try {
-            while(true){
-
-                // read bytes until reader indicates it's done
-                const { value, done } = await this.reader.read();
-                if(done){
-                    break;
-                }
-
-                // append received bytes to read buffer
-                this.readBuffer = [
-                    ...this.readBuffer,
-                    ...value,
-                ];
-
-                // process read buffer while there is enough bytes for a frame header
-                // 3 bytes frame header = (1 byte frame type) + (2 bytes frame length as unsigned 16-bit little endian)
-                const frameHeaderLength = 3;
-                while(this.readBuffer.length >= frameHeaderLength){
-                    try {
-
-                        // extract frame header
-                        const frameHeader = new BufferReader(this.readBuffer.slice(0, frameHeaderLength));
-
-                        // ensure frame type supported
-                        const frameType = frameHeader.readByte();
-                        if(frameType !== Constants.SerialFrameTypes.Incoming && frameType !== Constants.SerialFrameTypes.Outgoing){
-                            // unexpected byte, lets skip it and try again
-                            this.readBuffer = this.readBuffer.slice(1);
-                            continue;
-                        }
-
-                        // ensure frame length valid
-                        const frameLength = frameHeader.readUInt16LE();
-                        if(!frameLength){
-                            // unexpected byte, lets skip it and try again
-                            this.readBuffer = this.readBuffer.slice(1);
-                            continue;
-                        }
-
-                        // check if we have received enough bytes for this frame, otherwise wait until more bytes received
-                        const requiredLength = frameHeaderLength + frameLength;
-                        if(this.readBuffer.length < requiredLength){
-                            break;
-                        }
-
-                        // get frame data, and remove it and its frame header from the read buffer
-                        const frameData = this.readBuffer.slice(frameHeaderLength, requiredLength);
-                        this.readBuffer = this.readBuffer.slice(requiredLength);
-
-                        // handle received frame
-                        this.onFrameReceived(frameData);
-
-                    } catch(e) {
-                        console.error("Failed to process frame", e);
-                        break;
-                    }
-                }
-
-            }
-        } catch(error) {
-
-            // ignore error if reader was released
-            if(error instanceof TypeError){
-                return;
-            }
-
-            console.error('Error reading from serial port: ', error);
-
-        } finally {
-            this.reader.releaseLock();
-        }
-    }
-
     onFrameReceived(frame) {
 
         // console.log("onFrameReceived", frame);
@@ -391,4 +256,4 @@ class Device {
 
 }
 
-export default Device;
+export default Connection;
diff --git a/src/connection/serial_connection.js b/src/connection/serial_connection.js
new file mode 100644
index 0000000..ec69dab
--- /dev/null
+++ b/src/connection/serial_connection.js
@@ -0,0 +1,165 @@
+import BufferWriter from "../buffer_writer.js";
+import BufferReader from "../buffer_reader.js";
+import Constants from "../constants.js";
+import Connection from "./connection.js";
+
+class SerialConnection extends Connection {
+
+    constructor(serialPort) {
+        super();
+        this.serialPort = serialPort;
+        this.reader = serialPort.readable.getReader();
+        this.writable = serialPort.writable;
+        this.readBuffer = [];
+        this.readLoop();
+    }
+
+    static async open() {
+
+        // ensure browser supports web serial
+        if(!navigator.serial){
+            alert("Web Serial is not supported in this browser");
+            return null;
+        }
+
+        // ask user to select device
+        const serialPort = await navigator.serial.requestPort({
+            filters: [],
+        });
+
+        // open port
+        await serialPort.open({
+            baudRate: 115200,
+        });
+
+        return new SerialConnection(serialPort);
+
+    }
+
+    async close() {
+
+        // release reader lock
+        try {
+            this.reader.releaseLock();
+        } catch(e) {
+            // console.log("failed to release lock on serial port readable, ignoring...", e);
+        }
+
+        // close serial port
+        try {
+            await this.serialPort.close();
+        } catch(e) {
+            // console.log("failed to close serial port, ignoring...", e);
+        }
+
+    }
+
+    async write(bytes) {
+        const writer = this.writable.getWriter();
+        try {
+            await writer.write(new Uint8Array(bytes));
+        } finally {
+            writer.releaseLock();
+        }
+    }
+
+    async writeFrame(frameType, frameData) {
+
+        // create frame
+        const frame = new BufferWriter();
+
+        // add frame header
+        frame.writeByte(frameType);
+        frame.writeUInt16LE(frameData.length);
+
+        // add frame data
+        frame.writeBytes(frameData);
+
+        // write frame to device
+        await this.write(frame.toBytes());
+
+    }
+
+    async sendToRadioFrame(data) {
+        // write "app to radio" frame 0x3c "<"
+        await this.writeFrame(0x3c, data);
+    }
+
+    async readLoop() {
+        try {
+            while(true){
+
+                // read bytes until reader indicates it's done
+                const { value, done } = await this.reader.read();
+                if(done){
+                    break;
+                }
+
+                // append received bytes to read buffer
+                this.readBuffer = [
+                    ...this.readBuffer,
+                    ...value,
+                ];
+
+                // process read buffer while there is enough bytes for a frame header
+                // 3 bytes frame header = (1 byte frame type) + (2 bytes frame length as unsigned 16-bit little endian)
+                const frameHeaderLength = 3;
+                while(this.readBuffer.length >= frameHeaderLength){
+                    try {
+
+                        // extract frame header
+                        const frameHeader = new BufferReader(this.readBuffer.slice(0, frameHeaderLength));
+
+                        // ensure frame type supported
+                        const frameType = frameHeader.readByte();
+                        if(frameType !== Constants.SerialFrameTypes.Incoming && frameType !== Constants.SerialFrameTypes.Outgoing){
+                            // unexpected byte, lets skip it and try again
+                            this.readBuffer = this.readBuffer.slice(1);
+                            continue;
+                        }
+
+                        // ensure frame length valid
+                        const frameLength = frameHeader.readUInt16LE();
+                        if(!frameLength){
+                            // unexpected byte, lets skip it and try again
+                            this.readBuffer = this.readBuffer.slice(1);
+                            continue;
+                        }
+
+                        // check if we have received enough bytes for this frame, otherwise wait until more bytes received
+                        const requiredLength = frameHeaderLength + frameLength;
+                        if(this.readBuffer.length < requiredLength){
+                            break;
+                        }
+
+                        // get frame data, and remove it and its frame header from the read buffer
+                        const frameData = this.readBuffer.slice(frameHeaderLength, requiredLength);
+                        this.readBuffer = this.readBuffer.slice(requiredLength);
+
+                        // handle received frame
+                        this.onFrameReceived(frameData);
+
+                    } catch(e) {
+                        console.error("Failed to process frame", e);
+                        break;
+                    }
+                }
+
+            }
+        } catch(error) {
+
+            // ignore error if reader was released
+            if(error instanceof TypeError){
+                return;
+            }
+
+            console.error('Error reading from serial port: ', error);
+
+        } finally {
+            this.reader.releaseLock();
+        }
+    }
+
+}
+
+export default SerialConnection;
diff --git a/src/constants.js b/src/constants.js
index 756c903..0a3c5c0 100644
--- a/src/constants.js
+++ b/src/constants.js
@@ -3,7 +3,13 @@ class Constants {
     static SerialFrameTypes = {
         Incoming: 0x3e, // ">"
         Outgoing: 0x3c, // "<"
-    };
+    }
+
+    static Ble = {
+        ServiceUuid: "6E400001-B5A3-F393-E0A9-E50E24DCCA9E",
+        CharacteristicUuidRx: "6E400002-B5A3-F393-E0A9-E50E24DCCA9E",
+        CharacteristicUuidTx: "6E400003-B5A3-F393-E0A9-E50E24DCCA9E",
+    }
 
     static CommandCodes = {
         AppStart: 1,