From 73e3da212a79ba0c6498083890201f4b7c7bf33f Mon Sep 17 00:00:00 2001
From: jgromes <jan.gromes@gmail.com>
Date: Sun, 23 Jan 2022 12:05:30 +0100
Subject: [PATCH] [SX127x] Updated FHSS example formatting
---
.../SX127x_Receive_FHSS.ino | 162 +++++++++++-----
.../SX127x_Transmit_FHSS.ino | 179 ++++++++++++------
2 files changed, 239 insertions(+), 102 deletions(-)
diff --git a/examples/SX127x/SX127x_Receive_FHSS/SX127x_Receive_FHSS.ino b/examples/SX127x/SX127x_Receive_FHSS/SX127x_Receive_FHSS.ino
index 7ee31b83..3aeca4a8 100644
--- a/examples/SX127x/SX127x_Receive_FHSS/SX127x_Receive_FHSS.ino
+++ b/examples/SX127x/SX127x_Receive_FHSS/SX127x_Receive_FHSS.ino
@@ -15,56 +15,98 @@
For full API reference, see the GitHub Pages
https://jgromes.github.io/RadioLib/
- The SX1276 / 7 / 8 / 9 supports FHSS or Frequency Hopping Spread Spectrum.
- Once a hopping period is set and a transmission is started the radio
+ SX127x supports FHSS or Frequency Hopping Spread Spectrum.
+ Once a hopping period is set and a transmission is started, the radio
will begin triggering interrupts every hop period where the radio frequency
is changed to the next channel.
*/
-#include <RadioLib.h> //Click here to get the library: http://librarymanager/All#RadioLib
+#include <RadioLib.h>
-// SX1276 has the following connections:
-const int pin_cs = 10;
-const int pin_dio0 = 2;
-const int pin_dio1 = 9;
-const int pin_rst = 3;
-SX1276 radio = new Module(pin_cs, pin_dio0, pin_rst, pin_dio1);
+// SX1278 has the following connections:
+// NSS pin: 10
+// DIO0 pin: 2
+// RESET pin: 9
+// DIO1 pin: 3
+SX1278 radio = new Module(10, 2, 9, 3);
-volatile bool rxComplete = false;
-volatile bool fhssChange = false;
+// or using RadioShield
+// https://github.com/jgromes/RadioShield
+//SX1278 radio = RadioShield.ModuleA;
+
+// flag to indicate that a packet was received
+volatile bool receivedFlag = false;
+
+// flag to indicate frequency must be changed
+volatile bool fhssChangeFlag = false;
// the channel frequencies can be generated randomly or hard coded
-float channels[] = {908.0, 906.0, 907.0, 905.0, 903.0, 910.0, 909.0};
+// NOTE: The frequency list MUST be the same on both sides!
+float channels[] = { 433.0, 433.4, 433.2, 433.6, 434.0, 433.8 };
int numberOfChannels = sizeof(channels) / sizeof(float);
+// counter to keep track of how many frequency hops were performed
int hopsCompleted = 0;
+// this function is called when a complete packet
+// is received by the module
+// IMPORTANT: this function MUST be 'void' type
+// and MUST NOT have any arguments!
+#if defined(ESP8266) || defined(ESP32)
+ ICACHE_RAM_ATTR
+#endif
+void setRxFlag(void) {
+ receivedFlag = true;
+}
+
+// this function is called when FhssChangeChannel interrupt occurs
+// (at the beginning of each transmission)
+// IMPORTANT: this function MUST be 'void' type
+// and MUST NOT have any arguments!
+#if defined(ESP8266) || defined(ESP32)
+ ICACHE_RAM_ATTR
+#endif
+void setFHSSFlag(void) {
+ fhssChangeFlag = true;
+}
+
void setup() {
Serial.begin(9600);
// begin radio on home channel
- Serial.print(F("[SX127x] Initializing ... "));
+ Serial.print(F("[SX1278] Initializing ... "));
int state = radio.begin(channels[0]);
- if (state != RADIOLIB_ERR_NONE) {
- Serial.print(F("Failed with code: "));
+ if (state == RADIOLIB_ERR_NONE) {
+ Serial.println(F("success!"));
+ } else {
+ Serial.print(F("failed, code "));
Serial.println(state);
+ while (true);
}
- else
- Serial.println(F("Success!"));
- // set hop period to enable FHSS
+ // set hop period in symbols
+ // this will also enable FHSS
state = radio.setFHSSHoppingPeriod(9);
- if (state != RADIOLIB_ERR_NONE) {
- Serial.print(F("Error setting hopping period: "));
+ if (state == RADIOLIB_ERR_NONE) {
+ Serial.println(F("success!"));
+ } else {
+ Serial.print(F("failed, code "));
Serial.println(state);
+ while (true);
}
- radio.setDio0Action(dio0ISR); // called when transmission is finished
- radio.setDio1Action(dio1ISR); // called after a transmission has started, so we can move to next freq
+
+ // set the function to call when reception is finished
+ radio.setDio0Action(setRxFlag);
+
+ // set the function to call when we need to hcange frequency
+ radio.setDio1Action(setFHSSFlag);
// start listening for LoRa packets
Serial.print(F("[SX1278] Starting to listen ... "));
state = radio.startReceive();
- if (state != RADIOLIB_ERR_NONE) {
+ if (state == RADIOLIB_ERR_NONE) {
+ Serial.println(F("success!"));
+ } else {
Serial.print(F("failed, code "));
Serial.println(state);
while (true);
@@ -72,39 +114,67 @@ void setup() {
}
void loop() {
- if (rxComplete == true) {
- uint8_t incomingBuffer[255];
- radio.readData(incomingBuffer, 255);
- uint8_t receivedBytes = radio.getPacketLength();
- Serial.write(incomingBuffer, receivedBytes);
- Serial.println();
+ // check if the reception flag is set
+ if (receivedFlag == true) {
+ // you can read received data as an Arduino String
+ String str;
+ int state = radio.readData(str);
- Serial.print(F("Hops completed: "));
+ // you can also read received data as byte array
+ /*
+ byte byteArr[8];
+ int state = radio.readData(byteArr, 8);
+ */
+
+ if (state == RADIOLIB_ERR_NONE) {
+ // packet was successfully received
+ Serial.println(F("[SX1278] Received packet!"));
+
+ // print data of the packet
+ Serial.print(F("[SX1278] Data:\t\t"));
+ Serial.println(str);
+
+ } else if (state == RADIOLIB_ERR_CRC_MISMATCH) {
+ // packet was received, but is malformed
+ Serial.println(F("[SX1278] CRC error!"));
+
+ } else {
+ // some other error occurred
+ Serial.print(F("[SX1278] Failed, code "));
+ Serial.println(state);
+
+ }
+
+ // print the number of hops it took
+ Serial.print(F("[SX1278] Hops completed: "));
Serial.println(hopsCompleted);
+
+ // reset the counter
hopsCompleted = 0;
+ // put the module back to listen mode
radio.startReceive();
- rxComplete = false;
+ // we're ready to receive more packets, clear the flag
+ receivedFlag = false;
}
- if (fhssChange == true) {
- radio.setFrequency(channels[radio.getFHSSChannel() % numberOfChannels]);
+ // check if we need to do another frequency hop
+ if (fhssChangeFlag == true) {
+ // we do, change it now
+ int state = radio.setFrequency(channels[radio.getFHSSChannel() % numberOfChannels]);
+ if (state != RADIOLIB_ERR_NONE) {
+ Serial.print(F("[SX1278] Failed to change frequency, code "));
+ Serial.println(state);
+ }
+ // increment the counter
hopsCompleted++;
+
+ // clear the FHSS interrupt
radio.clearFHSSInt();
- fhssChange = false;
+
+ // we're ready to do another hop, clear the flag
+ fhssChangeFlag = false;
}
}
-
-// ISR when DIO0 goes low
-// called when transmission is complete or when RX is received
-void dio0ISR(void) {
- rxComplete = true;
-}
-
-// ISR when DIO1 goes low
-// called when FhssChangeChannel interrupt occurs (at the beginning of each transmission)
-void dio1ISR(void) {
- fhssChange = true;
-}
\ No newline at end of file
diff --git a/examples/SX127x/SX127x_Transmit_FHSS/SX127x_Transmit_FHSS.ino b/examples/SX127x/SX127x_Transmit_FHSS/SX127x_Transmit_FHSS.ino
index f1ecbaf8..b6182af5 100644
--- a/examples/SX127x/SX127x_Transmit_FHSS/SX127x_Transmit_FHSS.ino
+++ b/examples/SX127x/SX127x_Transmit_FHSS/SX127x_Transmit_FHSS.ino
@@ -15,99 +15,166 @@
For full API reference, see the GitHub Pages
https://jgromes.github.io/RadioLib/
- The SX1276 / 7 / 8 / 9 supports FHSS or Frequency Hopping Spread Spectrum.
- Once a hopping period is set and a transmission is started the radio
+ SX127x supports FHSS or Frequency Hopping Spread Spectrum.
+ Once a hopping period is set and a transmission is started, the radio
will begin triggering interrupts every hop period where the radio frequency
is changed to the next channel.
*/
-#include <RadioLib.h> //Click here to get the library: http://librarymanager/All#RadioLib
+#include <RadioLib.h>
-// SX1276 has the following connections:
-const int pin_cs = 10;
-const int pin_dio0 = 2;
-const int pin_dio1 = 9;
-const int pin_rst = 3;
-SX1276 radio = new Module(pin_cs, pin_dio0, pin_rst, pin_dio1);
+// SX1278 has the following connections:
+// NSS pin: 10
+// DIO0 pin: 2
+// RESET pin: 9
+// DIO1 pin: 3
+SX1278 radio = new Module(10, 2, 9, 3);
-volatile bool xmitComplete = false;
-volatile bool fhssChange = false;
+// or using RadioShield
+// https://github.com/jgromes/RadioShield
+//SX1278 radio = RadioShield.ModuleA;
+
+// flag to indicate that a packet was received
+volatile bool transmittedFlag = false;
+
+// flag to indicate frequency must be changed
+volatile bool fhssChangeFlag = false;
// the channel frequencies can be generated randomly or hard coded
-float channels[] = {908.0, 906.0, 907.0, 905.0, 903.0, 910.0, 909.0};
+// NOTE: The frequency list MUST be the same on both sides!
+float channels[] = { 433.0, 433.4, 433.2, 433.6, 434.0, 433.8 };
int numberOfChannels = sizeof(channels) / sizeof(float);
+// counter to keep track of how many frequency hops were performed
int hopsCompleted = 0;
-int counter = 0;
+
+// counter that increments with each sent packet
+int packetCounter = 0;
+
+// save transmission state between loops
+int transmissionState = RADIOLIB_ERR_NONE;
+
+// this is the packet that will be sent
+String longPacket = "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: ";
+
+// this function is called when a complete packet
+// is transmitted by the module
+// IMPORTANT: this function MUST be 'void' type
+// and MUST NOT have any arguments!
+#if defined(ESP8266) || defined(ESP32)
+ ICACHE_RAM_ATTR
+#endif
+void setTxFlag(void) {
+ transmittedFlag = true;
+}
+
+// this function is called when FhssChangeChannel interrupt occurs
+// (at the beginning of each transmission)
+// IMPORTANT: this function MUST be 'void' type
+// and MUST NOT have any arguments!
+#if defined(ESP8266) || defined(ESP32)
+ ICACHE_RAM_ATTR
+#endif
+void setFHSSFlag(void) {
+ fhssChangeFlag = true;
+}
void setup() {
Serial.begin(9600);
// begin radio on home channel
- Serial.print(F("[SX127x] Initializing ... "));
+ Serial.print(F("[SX1278] Initializing ... "));
int state = radio.begin(channels[0]);
- if (state != RADIOLIB_ERR_NONE) {
- Serial.print(F("Failed with code: "));
+ if (state == RADIOLIB_ERR_NONE) {
+ Serial.println(F("success!"));
+ } else {
+ Serial.print(F("failed, code "));
Serial.println(state);
+ while (true);
}
- else
- Serial.println(F("Success!"));
- // set hop period to enable FHSS
+ // set hop period in symbols
+ // this will also enable FHSS
state = radio.setFHSSHoppingPeriod(9);
- if(state != RADIOLIB_ERR_NONE) {
- Serial.print(F("Error setting hopping period: "));
+ if (state == RADIOLIB_ERR_NONE) {
+ Serial.println(F("success!"));
+ } else {
+ Serial.print(F("failed, code "));
Serial.println(state);
+ while (true);
}
- radio.setDio0Action(dio0ISR); // called when transmission is finished
- radio.setDio1Action(dio1ISR); // called after a transmission has started, so we can move to next freq
+ // set the function to call when transmission is finished
+ radio.setDio0Action(setTxFlag);
- Serial.print(F("Transmitting packet..."));
+ // set the function to call when we need to hcange frequency
+ radio.setDio1Action(setFHSSFlag);
- 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: ";
-
- state = radio.startTransmit(longOutput + counter);
- if (state != RADIOLIB_ERR_NONE) {
- Serial.print(F("Error transmitting with code: "));
- Serial.println(state);
- }
+ // start transmitting the first packet
+ Serial.print(F("[SX1278] Sending first packet ... "));
+ transmissionState = radio.startTransmit(longPacket + packetCounter);
}
void loop() {
- if (xmitComplete == true) {
- xmitComplete = false;
- Serial.println(F("Transmit complete"));
- Serial.print(F("Radio after xmit is on channel: "));
+ // check if the transmission flag is set
+ if (transmittedFlag == true) {
+ // reset flag
+ transmittedFlag = false;
+
+ if (transmissionState == RADIOLIB_ERR_NONE) {
+ // packet was successfully sent
+ Serial.println(F("transmission finished!"));
+
+ } else {
+ Serial.print(F("failed, code "));
+ Serial.println(transmissionState);
+
+ }
+
+ // The channel is automatically reset to 0 upon completion
+ Serial.print(F("[SX1278] Radio is on channel: "));
Serial.println(radio.getFHSSChannel());
- // the FHSS channel is automatically reset to 0 upon end of transmission
- radio.setFrequency(channels[radio.getFHSSChannel() % numberOfChannels]); // Return to home channel before next transaction
-
- Serial.print(F("Hops completed: "));
+ // print the number of hops it took
+ Serial.print(F("[SX1278] Hops completed: "));
Serial.println(hopsCompleted);
+
+ // reset the counter
hopsCompleted = 0;
- radio.startReceive();
- }
-
- if (fhssChange == true) {
+ // return to home channel before the next transaction
radio.setFrequency(channels[radio.getFHSSChannel() % numberOfChannels]);
+ // wait a second before transmitting again
+ delay(1000);
+
+ // increment the packet counter
+ packetCounter++;
+
+ // send another packet
+ Serial.print(F("[SX1278] Sending another packet ... "));
+ transmissionState = radio.startTransmit(longPacket + packetCounter);
+ }
+
+ // check if we need to do another frequency hop
+ if (fhssChangeFlag == true) {
+ // we do, change it now
+ int state = radio.setFrequency(channels[radio.getFHSSChannel() % numberOfChannels]);
+ if (state != RADIOLIB_ERR_NONE) {
+ Serial.print(F("[SX1278] Failed to change frequency, code "));
+ Serial.println(state);
+ }
+
+ // increment the counter
hopsCompleted++;
- fhssChange = false;
+
+ // clear the FHSS interrupt
radio.clearFHSSInt();
+
+ // we're ready to do another hop, clear the flag
+ fhssChangeFlag = false;
}
}
-
-// ISR when DIO0 goes low
-// called when transmission is complete or when RX is received
-void dio0ISR(void) {
- xmitComplete = true;
-}
-
-// ISR when DIO1 goes low
-// called when FhssChangeChannel interrupt occurs (at regular HoppingPeriods)
-void dio1ISR(void) {
- fhssChange = true;
-}