113 lines
3.6 KiB
C++
113 lines
3.6 KiB
C++
/*
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RadioLib SX127x Transmit with Frequency Hopping Example
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This example transmits packets using SX1278 LoRa radio module.
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Each packet contains up to 256 bytes of data, in the form of:
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- Arduino String
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- null-terminated char array (C-string)
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- arbitrary binary data (byte array)
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Other modules from SX127x/RFM9x family can also be used.
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For default module settings, see the wiki page
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https://github.com/jgromes/RadioLib/wiki/Default-configuration#sx127xrfm9x---lora-modem
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For full API reference, see the GitHub Pages
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https://jgromes.github.io/RadioLib/
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The SX1276 / 7 / 8 / 9 supports FHSS or Frequency Hopping Spread Spectrum.
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Once a hopping period is set and a transmission is started the radio
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will begin triggering interrupts every hop period where the radio frequency
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is changed to the next channel.
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*/
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#include <RadioLib.h> //Click here to get the library: http://librarymanager/All#RadioLib
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// SX1276 has the following connections:
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const int pin_cs = 10;
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const int pin_dio0 = 2;
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const int pin_dio1 = 9;
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const int pin_rst = 3;
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SX1276 radio = new Module(pin_cs, pin_dio0, pin_rst, pin_dio1);
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volatile bool xmitComplete = false;
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volatile bool fhssChange = false;
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// the channel frequencies can be generated randomly or hard coded
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float channels[] = {908.0, 906.0, 907.0, 905.0, 903.0, 910.0, 909.0};
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int numberOfChannels = sizeof(channels) / sizeof(float);
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int hopsCompleted = 0;
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int counter = 0;
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void setup() {
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Serial.begin(9600);
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// begin radio on home channel
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Serial.print(F("[SX127x] Initializing ... "));
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int state = radio.begin(channels[0]);
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if (state != RADIOLIB_ERR_NONE) {
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Serial.print(F("Failed with code: "));
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Serial.println(state);
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}
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else
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Serial.println(F("Success!"));
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// set hop period to enable FHSS
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state = radio.setFHSSHoppingPeriod(9);
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if(state != RADIOLIB_ERR_NONE) {
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Serial.print(F("Error setting hopping period: "));
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Serial.println(state);
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}
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radio.setDio0Action(dio0ISR); // called when transmission is finished
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radio.setDio1Action(dio1ISR); // called after a transmission has started, so we can move to next freq
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Serial.print(F("Transmitting packet..."));
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String longOutput = "Let's create a really long packet to trigger lots of hop interrupts. A packet can be up to 256 bytes long. This packet is 222 bytes so using sf = 9, bw = 125, timeOnAir is 1488ms. 1488ms / (9*4.10ms) = 40 hops. Counter: ";
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state = radio.startTransmit(longOutput + counter);
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if (state != RADIOLIB_ERR_NONE) {
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Serial.print(F("Error transmitting with code: "));
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Serial.println(state);
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}
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}
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void loop() {
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if (xmitComplete == true) {
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xmitComplete = false;
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Serial.println(F("Transmit complete"));
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Serial.print(F("Radio after xmit is on channel: "));
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Serial.println(radio.getFHSSChannel());
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// the FHSS channel is automatically reset to 0 upon end of transmission
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radio.setFrequency(channels[radio.getFHSSChannel() % numberOfChannels]); // Return to home channel before next transaction
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Serial.print(F("Hops completed: "));
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Serial.println(hopsCompleted);
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hopsCompleted = 0;
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radio.startReceive();
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}
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if (fhssChange == true) {
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radio.setFrequency(channels[radio.getFHSSChannel() % numberOfChannels]);
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hopsCompleted++;
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fhssChange = false;
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radio.clearFHSSInt();
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}
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}
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// ISR when DIO0 goes low
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// called when transmission is complete or when RX is received
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void dio0ISR(void) {
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xmitComplete = true;
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}
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// ISR when DIO1 goes low
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// called when FhssChangeChannel interrupt occurs (at regular HoppingPeriods)
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void dio1ISR(void) {
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fhssChange = true;
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}
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