前言
node-red-contrib-ble-heart-rate 是一个基于 Node-RED 平台的 BLE 心率数据流采集插件。本文将介绍此插件的使用和安装方法，并提供实用的代码示例。
安装
在 Node-RED 管理面板中搜索 node-red-contrib-ble-heart-rate 并进行安装即可。或者，您也可以在终端中使用以下命令进行安装：
npm install node-red-contrib-ble-heart-rate
使用教程
node-red-contrib-ble-heart-rate 可以作为 Node-RED 中的一个节点来使用。例如，可以将其与 BLE 设备安装在一起并进行数据流传输。使用此节点，可以方便地获取 BLE 设备中的心率数据信息。
在 Node-RED 编辑器中，可以首先创建一个 BLE 连接节点，以建立设备和 Node-RED 之间的连接。然后，通过将 BLE Heart Rate 节点添加到流程中，可以从设备中捕获心率数据流并进行处理。
BLE 连接节点
对于 BLE 连接的节点，可以使用 node-red-contrib-generic-ble 包。此包包含 BLE Scan 和 BLE Connect 节点，可以帮助我们建立与 BLE 设备的连接。
以下是一个示例流程：
[{"id":"fbde68d3.1b2ab8","type":"blescan","z":"d58076ca.47c488","name":"","mac":"","interval":"30","duration":"5","allow_duplicates":true,"x":150,"y":100,"wires":[["e938e88.484787"]]},{"id":"e938e88.484787","type":"debug","z":"d58076ca.47c488","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":430,"y":100,"wires":[]},{"id":"3651a022.3302f8","type":"ble-connect","z":"d58076ca.47c488","name":"","deviceName":"","x":447,"y":243,"wires":[["45dc7c3d.e0cc3"]]},{"id":"45dc7c3d.e0cc3","type":"debug","z":"d58076ca.47c488","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":655,"y":246,"wires":[]},{"id":"83ba6f7b.032b48","type":"inject","z":"d58076ca.47c488","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"true","payloadType":"bool","x":150,"y":220,"wires":[["3651a022.3302f8"]]}]在此示例中，我们使用了 blescan 节点来扫描附近所有的 BLE 设备，并使用 ble-connect 节点来建立连接。
BLE Heart Rate 节点
在成功建立连接之后，可以使用 node-red-contrib-ble-heart-rate 包中的 BLE Heart Rate 节点来获取心率数据流。
以下是一个示例流程：
[{"id":"cd4bb4a4.4a4f98","type":"debug","z":"ce3221dd.10724","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","statusVal":"","statusType":"auto","x":470,"y":120,"wires":[]},{"id":"6c92d6a7.446e28","type":"ble-heart-rate","z":"ce3221dd.10724","name":"","x":330,"y":120,"wires":[["cd4bb4a4.4a4f98"]]}]在此示例中，我们使用了 ble-heart-rate 节点，并将其连接到 debug 节点，以便在控制台中显示心率数据信息。
示例代码
以下是一个完整的 Node-RED 流程示例：
[{"id":"2d1b9448.b47fda","type":"blescan","z":"4dbcba8e.8909cc","name":"","mac":"","interval":"30","duration":"5","allow_duplicates":true,"x":260,"y":100,"wires":[["9faa3ae3.4527a"]]},{"id":"9faa3ae3.4527a","type":"ble-connect","z":"4dbcba8e.8909cc","name":"","deviceName":"Device","x":480,"y":180,"wires":[["f1de9b49.53d328"]]},{"id":"f1de9b49.53d328","type":"ble-heart-rate","z":"4dbcba8e.8909cc","name":"","x":490,"y":280,"wires":[["c797d26.8e28378"]]},{"id":"c797d26.8e28378","type":"debug","z":"4dbcba8e.8909cc","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","targetType":"msg","statusVal":"","statusType":"auto","x":630,"y":380,"wires":[]},{"id":"e1aa2eb5.76b9b","type":"inject","z":"4dbcba8e.8909cc","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"true","payloadType":"bool","x":240,"y":220,"wires":[["9faa3ae3.4527a"]]}]此示例代码中包含一个芯片设备的连接，以及从设备中捕获心率数据流并在控制台显示的示例流程。
结论
node-red-contrib-ble-heart-rate 对于需要使用 BLE 传感器设备收集心率数据的应用程序是一个不错的选择。随着 Node-RED 和 BLE 技术的发展，其使用的案例和适用范围也不断扩大。希望本文能够为您提供有关此插件的详细和实用信息，并有助于您在以后的开发和应用中更好地使用它。
来源：JavaScript中文网 ，转载请注明来源 https://www.javascriptcn.com/post/60056cb581e8991b448e6215