88 lines
2.9 KiB
C++
88 lines
2.9 KiB
C++
/*
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LoRa Duplex communication with Spreading Factor
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Sends a message every half second, and polls continually
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for new incoming messages. Sets the LoRa radio's spreading factor.
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Spreading factor affects how far apart the radio's transmissions
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are, across the available bandwidth. Radios with different spreading
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factors will not receive each other's transmissions. This is one way you
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can filter out radios you want to ignore, without making an addressing scheme.
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Spreading factor affects reliability of transmission at high rates, however,
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so avoid a hugh spreading factor when you're sending continually.
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See the Semtech datasheet, http://www.semtech.com/images/datasheet/sx1276.pdf
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for more on Spreading Factor.
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created 28 April 2017
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by Tom Igoe
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*/
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#include <SPI.h> // include libraries
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#include <LoRa.h>
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const int csPin = 7; // LoRa radio chip select
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const int resetPin = 6; // LoRa radio reset
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const int irqPin = 1; // change for your board; must be a hardware interrupt pin
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byte msgCount = 0; // count of outgoing messages
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int interval = 2000; // interval between sends
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long lastSendTime = 0; // time of last packet send
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void setup() {
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Serial.begin(9600); // initialize serial
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while (!Serial);
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Serial.println("LoRa Duplex - Set spreading factor");
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// override the default CS, reset, and IRQ pins (optional)
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LoRa.setPins(csPin, resetPin, irqPin); // set CS, reset, IRQ pin
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if (!LoRa.begin(915E6)) { // initialize ratio at 915 MHz
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Serial.println("LoRa init failed. Check your connections.");
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while (true); // if failed, do nothing
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}
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LoRa.setSpreadingFactor(8); // ranges from 6-12,default 7 see API docs
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Serial.println("LoRa init succeeded.");
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}
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void loop() {
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if (millis() - lastSendTime > interval) {
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String message = "HeLoRa World! "; // send a message
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message += msgCount;
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sendMessage(message);
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Serial.println("Sending " + message);
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lastSendTime = millis(); // timestamp the message
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interval = random(2000) + 1000; // 2-3 seconds
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msgCount++;
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}
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// parse for a packet, and call onReceive with the result:
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onReceive(LoRa.parsePacket());
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}
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void sendMessage(String outgoing) {
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LoRa.beginPacket(); // start packet
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LoRa.print(outgoing); // add payload
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LoRa.endPacket(); // finish packet and send it
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msgCount++; // increment message ID
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}
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void onReceive(int packetSize) {
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if (packetSize == 0) return; // if there's no packet, return
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// read packet header bytes:
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String incoming = "";
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while (LoRa.available()) {
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incoming += (char)LoRa.read();
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}
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Serial.println("Message: " + incoming);
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Serial.println("RSSI: " + String(LoRa.packetRssi()));
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Serial.println("Snr: " + String(LoRa.packetSnr()));
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Serial.println();
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}
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