| 1 | // ArduinoJson - https://arduinojson.org |
| 2 | // Copyright © 2014-2026, Benoit BLANCHON |
| 3 | // MIT License |
| 4 | // |
| 5 | // This example shows how to send a JSON document to a UDP socket. |
| 6 | // At regular interval, it sends a UDP packet that contains the status of |
| 7 | // analog and digital pins. |
| 8 | // It looks like that: |
| 9 | // { |
| 10 | // "analog": [0, 76, 123, 158, 192, 205], |
| 11 | // "digital": [1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0] |
| 12 | // } |
| 13 | // |
| 14 | // If you want to test this program, you need to be able to receive the UDP |
| 15 | // packets. |
| 16 | // For example, you can run netcat on your computer |
| 17 | // $ ncat -ulp 8888 |
| 18 | // See https://nmap.org/ncat/ |
| 19 | // |
| 20 | // https://arduinojson.org/v7/example/udp-beacon/ |
| 21 | |
| 22 | #include <ArduinoJson.h> |
| 23 | #include <Ethernet.h> |
| 24 | #include <SPI.h> |
| 25 | |
| 26 | byte mac[] = {0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED}; |
| 27 | IPAddress remoteIp(192, 168, 0, 108); // <- EDIT!!!! |
| 28 | unsigned short remotePort = 8888; |
| 29 | unsigned short localPort = 8888; |
| 30 | EthernetUDP udp; |
| 31 | |
| 32 | void setup() { |
| 33 | // Initialize serial port |
| 34 | Serial.begin(9600); |
| 35 | while (!Serial) |
| 36 | continue; |
| 37 | |
| 38 | // Initialize Ethernet libary |
| 39 | if (!Ethernet.begin(mac)) { |
| 40 | Serial.println(F("Failed to initialize Ethernet library")); |
| 41 | return; |
| 42 | } |
| 43 | |
| 44 | // Enable UDP |
| 45 | udp.begin(localPort); |
| 46 | } |
| 47 | |
| 48 | void loop() { |
| 49 | // Allocate a temporary JsonDocument |
| 50 | JsonDocument doc; |
| 51 | |
| 52 | // Create the "analog" array |
| 53 | JsonArray analogValues = doc["analog"].to<JsonArray>(); |
| 54 | for (int pin = 0; pin < 6; pin++) { |
| 55 | // Read the analog input |
| 56 | int value = analogRead(pin); |
| 57 | |
| 58 | // Add the value at the end of the array |
| 59 | analogValues.add(value); |
| 60 | } |
| 61 | |
| 62 | // Create the "digital" array |
| 63 | JsonArray digitalValues = doc["digital"].to<JsonArray>(); |
| 64 | for (int pin = 0; pin < 14; pin++) { |
| 65 | // Read the digital input |
| 66 | int value = digitalRead(pin); |
| 67 | |
| 68 | // Add the value at the end of the array |
| 69 | digitalValues.add(value); |
| 70 | } |
| 71 | |
| 72 | // Log |
| 73 | Serial.print(F("Sending to ")); |
| 74 | Serial.print(remoteIp); |
| 75 | Serial.print(F(" on port ")); |
| 76 | Serial.println(remotePort); |
| 77 | serializeJson(doc, Serial); |
| 78 | |
| 79 | // Send UDP packet |
| 80 | udp.beginPacket(remoteIp, remotePort); |
| 81 | serializeJson(doc, udp); |
| 82 | udp.println(); |
| 83 | udp.endPacket(); |
| 84 | |
| 85 | // Wait |
| 86 | delay(10000); |
| 87 | } |
| 88 | |
| 89 | // Performance issue? |
| 90 | // ------------------ |
| 91 | // |
| 92 | // EthernetUDP is an unbuffered stream, which is not optimal for ArduinoJson. |
| 93 | // See: https://arduinojson.org/v7/how-to/improve-speed/ |
| 94 | |
| 95 | // See also |
| 96 | // -------- |
| 97 | // |
| 98 | // https://arduinojson.org/ contains the documentation for all the functions |
| 99 | // used above. It also includes an FAQ that will help you solve any |
| 100 | // serialization problem. |
| 101 | // |
| 102 | // The book "Mastering ArduinoJson" contains a tutorial on serialization. |
| 103 | // It begins with a simple example, then adds more features like serializing |
| 104 | // directly to a file or any stream. |
| 105 | // Learn more at https://arduinojson.org/book/ |
| 106 | // Use the coupon code TWENTY for a 20% discount ❤❤❤❤❤ |