[209] | 1 | /*
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| 2 | Example of using a Stream object to store the message payload
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| 3 |
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| 4 | Uses SRAM library: https://github.com/ennui2342/arduino-sram
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| 5 | but could use any Stream based class such as SD
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| 6 |
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| 7 | - connects to an MQTT server
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| 8 | - publishes "hello world" to the topic "outTopic"
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| 9 | - subscribes to the topic "inTopic"
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| 10 | */
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| 11 |
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| 12 | #include <SPI.h>
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| 13 | #include <Ethernet.h>
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| 14 | #include <PubSubClient.h>
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| 15 | #include <SRAM.h>
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| 16 |
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| 17 | // Update these with values suitable for your network.
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| 18 | byte mac[] = { 0xDE, 0xED, 0xBA, 0xFE, 0xFE, 0xED };
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| 19 | IPAddress ip(172, 16, 0, 100);
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| 20 | IPAddress server(172, 16, 0, 2);
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| 21 |
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| 22 | SRAM sram(4, SRAM_1024);
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| 23 |
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| 24 | void callback(char* topic, byte* payload, unsigned int length) {
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| 25 | sram.seek(1);
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| 26 |
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| 27 | // do something with the message
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| 28 | for(uint8_t i=0; i<length; i++) {
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| 29 | Serial.write(sram.read());
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| 30 | }
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| 31 | Serial.println();
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| 32 |
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| 33 | // Reset position for the next message to be stored
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| 34 | sram.seek(1);
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| 35 | }
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| 36 |
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| 37 | EthernetClient ethClient;
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| 38 | PubSubClient client(server, 1883, callback, ethClient, sram);
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| 39 |
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| 40 | void setup()
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| 41 | {
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| 42 | Ethernet.begin(mac, ip);
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| 43 | if (client.connect("arduinoClient")) {
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| 44 | client.publish("outTopic","hello world");
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| 45 | client.subscribe("inTopic");
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| 46 | }
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| 47 |
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| 48 | sram.begin();
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| 49 | sram.seek(1);
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| 50 |
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| 51 | Serial.begin(9600);
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| 52 | }
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| 53 |
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| 54 | void loop()
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| 55 | {
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| 56 | client.loop();
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| 57 | }
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