How-To Guides
Flows Guides
Create Audio Notifications for Sensor Readings
1min
You can use Flows to create dashboards to notify you when sensor anomalies occur.
Imagine a situation in an automobile assembly plant temperature sensors detect readings that are beyond the normal range. In such a scenario, the system can immediately trigger an audio alert, which can help to quickly address potential issues.
To create a flow that notifies you of temperature reading alerts:
- In Manufacturing connect Edge, navigate to the Flows Manager and create a new flow. See Create a Flow to learn more.
- Drag an Inject node, Function node, and Serial out node onto the canvas and connect them.
Create a new connection by adding Serial in, Function, and Audio out nodes to the canvas and connecting them together. The two connections should be connected as shown below.
- Double-click either the Serial in or Serial out node. The Edit serial node dialog box appears.
- Serial Port: Click the Edit icon. The Edit serial-port node page opens.
- Create a configuration for the connected device. Make sure that the Serial Port and Baud rate match the device information.
- Click Update.
- Click Done.
- Repeat step 4 to configure each serial node in the flow.
- Double-click the Inject node. The Edit inject node dialog box appears.
- msg.payload: Select string from the drop-down option and enter a string message that requests the desired data from it. In this use case, F is used to request temperature data in Fahrenheit from the sensor.
- Repeat: Set an interval to have the node automatically request data after every one second.
Click Done.
- Double-click the Audio out node. The Edit audio out node dialog box appears.
- TTS Voice: Select a voice to use.
- Play audio when window not in focus: Select the check box to hear the alert when the flow is minimized.
- Group: If needed, click the Edit icon to create a dashboard.
- Name: Enter a user-defined name.
Click Done.
- Double-click the Function node connected to the Inject node and Serial out node. The Edit function node dialog box appears.
- On Message: Enter code that adds a carriage return to the message to ensure that the device reads it properly. msg.payload = msg.payload + "\r"; // Add a carriage return to the output. return msg;
- Double-click the Function node connected to the Serial in node and Audio out node. The Edit function node dialog box appears.
- On Message: Enter code that checks for the sensor reading and outputs a message when it is above or below a certain threshold. var val = parseFloat(msg.payload); // Gets the temperature in degrees Fahrenheit from the string sent by the device. if (val > 70.0) { // Checks for if the temperature is higher than 70 deg F msg.payload = "high"; // Sets the notification message to say "high" when the temperature is high. } else { msg.payload = "low"; // Sets the notification message to say "low" when the temperature is lower than 70 deg F. } return msg;
- Click Deploy and expand the message window beneath the flow.
Click the Dashboard icon. Then, click the Expand icon to open the dashboard to begin hearing the audio notifications.