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--- docs:blox:blox-wifi-messages [2024/08/27 12:22]
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+++ docs:blox:blox-wifi-messages [2024/08/28 17:26] (current)
admin
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-====== 6.6.3 Broadcasting and Receiving messages over  WIFI in BLOX firmware =======
+====== 6.6.3 Broadcasting and Receiving messages over WIFI in BLOX firmware ======
+Broadcasting and Receiving messages over WIFI allows you to link multiple BLOX devices together across your local WIFI network. It can also be used to interact with external applications
+===== 6.6.3.1 BLOX Communication System Overview =====
+===== Message Sending and Receiving : =====
+BLOX devices communicate using [[https://en.wikipedia.org/wiki/User_Datagram_Protocol|UDP]] to send (broadcast) and receive messages. Each message includes a sensor value (analog or digital) and a unique ID Tag you get to set. The tags allows devices to filter whether they need to pay attention to the message
+**ID Tag****-Based Processing**:
+   * **Sending**: When BLOX1 sends a message, you tags the sensor value with a specific ID Tag.
+  * **Receiving**: All devices on the network receive the message. However, each BLOX device is configured to act only on messages with specific ID Tags.
+      * **BLOX2 Example**: If BLOX 2 is set up with an IF block to look for a message with a certain ID Tag, it will execute subsequent blocks when a message with that ID Tag is received, using the included sensor value.
+      * **BLOX3 Example**: If BLOX 3 is not set up to listen for that ID Tag, it will ignore the message.
+**Multiple Listeners**:
+Multiple BLOX devices can be configured to respond to the same ID Tag, allowing for coordinated actions across devices.
+**Cross-Platform Compatibility**:
+The UDP messages can be used with other applications as well. For example, a Python or Node.js script on a computer can send or receive these UDP packets, allowing for integration with external software and systems.
+This setup provides a flexible and extensible way to manage inter-device communication and integration with other networked applications.
+===== 6.6.3.2 Sending Messages =====
+You can send analog or digital sensor values
+Note the matching ID Tags (compared to receiving section below) to identify the outgoing messages
+^Sending an analog sensor value^Sending a digital sensor value|
+|{{:docs:blox:pasted:20240828-170512.png}}|{{:docs:blox:pasted:20240828-172440.png}}|
+----
+===== 6.6.3.3 Receiving Messages =====
+Received messages are available as "sensors" for use on the other device / devices
+Note the matching ID Tags (compared to sending section above) to identify the incoming messages
+^Receiving analog sensor value^Receiving digital sensor value|
+|{{docs:blox:pasted:20240828-172622.png}}|{{:docs:blox:pasted:20240828-172524.png}}|
+----
+===== 6.6.3.4 Monitoring / troubleshooting messages =====
+You can see broadcast messages in the BLOX Serial/USB logs
+{{:docs:blox:pasted:20240828-171736.png}}
+Messages are broadcast unencrypted for simplicity. This also allows you to very easily monitor and troubleshoot issues, as well as integrate it into other scripts and programs
+For example you can listen out for messages / send messages from a computer to help you troubleshoot
+{{:docs:blox:pasted:20240828-171245.png}}
+----
+===== 6.6.3.4 3rd party integration =====
+You can use your own code to send and receive UDP messages in the format of idtagstring=value on port 49160
+**Technical Details**:
+BLOX sends and receives on port 49160
+Data is sent as a simple string in the format idtag=value. For analog sensors the value is the numeric value. For digital sensors its 0/1 respectively. Quite simple and easy
+For example: Sending via a custom nodejs program
+<code>
+const dgram = require('dgram');
+// Create a UDP socket
+const client = dgram.createSocket('udp4');
+// Enable broadcast on the socket
+client.on('listening', function() {
+  client.setBroadcast(true);
+});
+// The message to send
+const message = Buffer.from('analog_read_1_blox_2=115'); // construct value dynamically in your own code
+// The target port and broadcast address
+const PORT = 49160;
+const BROADCAST_ADDR = '255.255.255.255';
+// Send the message
+client.send(message, 0, message.length, PORT, BROADCAST_ADDR, (err) => {
+  if (err) {
+    console.error(`Error sending message: ${err}`);
+  } else {
+    console.log('Message broadcasted successfully');
+  }
+  client.close();
+});
+</code>
+For example: Receiving via a custom nodejs program
+<code>
+const dgram = require('dgram');
+// Create a UDP socket for the server
+const server = dgram.createSocket('udp4');
+// Define the port to listen on
+const PORT = 49160;
+// Event listener for when the server receives a message
+server.on('message', (msg, rinfo) => {
+  const message = msg.toString();
+  const keyValue = message.split('=');
+  // Check if the message is in the expected format
+  if (keyValue.length === 2 && keyValue[0] === 'analog_read_1_blox_2') {
+    const value = keyValue[1];
+    console.log(`Received analog_read_1_blox_2 value: ${value}`);
+    // do something with the value
+  }
+});
+// Event listener for when the server starts listening
+server.on('listening', () => {
+  const address = server.address();
+  console.log(`Server listening on ${address.address}:${address.port}`);
+});
+// Bind the server to the port
+server.bind(PORT);
+</code>
-===== 6.6.3.1 Sending Messages =====
-===== 6.6.3.2 Receiving Messages =====

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