Add scanStart/scanStop/scanRestart commands

Author: Daisuke Baba

README.md

@@ -11,6 +11,11 @@ The node should still work on macOS and Windows as nothing is modified for these
 
 Supported operations are as follows:
 
+- Start BLE Scanning
+- Stop BLE Scanning
+- Restart BLE Scanning (Stop then start BLE Scanning again)
+- Connect to a peripheral device
+- Disonnect from a peripheral device
 - Read
 - Write
 - Write without Response

src/generic-ble.js

@@ -184,6 +184,7 @@ function startBLEScanning(RED) {
   noble.addListener('error', handlers.onError);
 
   if (noble.state === 'poweredOn') {
+    RED.log.info(`[GenericBLE] Start BLE scanning`);
     noble.startScanning([], true);
     genericBleState.scanning = true;
   } else {
@@ -803,7 +804,19 @@ module.exports = function (RED) {
             // ignore
           }
           try {
-            if (msg.topic === 'connect') {
+            if (msg.topic === 'scanStart') {
+              startBLEScanning(RED);
+              return;
+            } else if (msg.topic === 'scanStop') {
+              stopBLEScanning(RED);
+              return;
+            } else if (msg.topic === 'scanRestart') {
+              stopBLEScanning(RED);
+              setTimeout(() => {
+                startBLEScanning(RED);
+              }, 1000);
+              return;
+            } else if (msg.topic === 'connect') {
               await this.genericBleNode.connectPeripheral();
             } else if (msg.topic === 'disconnect') {
               await this.genericBleNode.disconnectPeripheral();

src/locales/en-US/generic-ble.html

@@ -22,12 +22,28 @@ <h3>Inputs</h3>
 <p>
 Expects a message used for peripheral connecting/disconnecting operation, triggering <code>Read</code> operation, or subscribing <code>Notify</code> events.
 <dl>
-<dt>For <code>Connect</code> operation:</dt>
+<dt>For <code>scanStart</code> operation:</dt>
+<dd>
+In order to start BLE scanning to discover peripheral devices, set <code>msg.topic</code> to <code>scanStart</code>.
+<code>msg.payload</code> is always ignored. This operation doesn't emit anything from the Output port.
+</dd>
+<dt>For <code>scanStop</code> operation:</dt>
+<dd>
+In order to stop BLE scanning, set <code>msg.topic</code> to <code>scanStop</code>.
+<code>msg.payload</code> is always ignored. This operation doesn't emit anything from the Output port.
+</dd>
+<dt>For <code>scanRestart</code> operation:</dt>
+<dd>
+In order to restart BLE scanning, set <code>msg.topic</code> to <code>scanRestart</code>.
+This operation performs <code>ScanStop</code> then <code>ScanStart</code>.
+<code>msg.payload</code> is always ignored. This operation doesn't emit anything from the Output port.
+</dd>
+<dt>For <code>connect</code> operation:</dt>
 <dd>
 In order to connect a peripheral device, set <code>msg.topic</code> to <code>connect</code>.
 <code>msg.payload</code> is always ignored. This operation doesn't emit anything from the Output port.
 </dd>
-<dt>For <code>Disonnect</code> operation:</dt>
+<dt>For <code>disconnect</code> operation:</dt>
 <dd>
 In order to disconnect a peripheral device, set <code>msg.topic</code> to <code>disconnect</code>.
 <code>msg.payload</code> is always ignored. This operation doesn't emit anything from the Output port.