diff --git a/FDRS_Sensor/fdrs_sensor.h b/FDRS_Sensor/fdrs_sensor.h
index a743b78..a963e59 100644
--- a/FDRS_Sensor/fdrs_sensor.h
+++ b/FDRS_Sensor/fdrs_sensor.h
@@ -57,10 +57,18 @@ typedef struct __attribute__((packed)) DataReading {
} DataReading;
+
+enum crcResult{
+ CRC_NULL,
+ CRC_OK,
+ CRC_BAD,
+} returnCRC;
+
enum {
cmd_clear,
cmd_ping,
cmd_add,
+ cmd_ack,
};
typedef struct __attribute__((packed)) SystemPacket {
@@ -70,8 +78,11 @@ typedef struct __attribute__((packed)) SystemPacket {
const uint16_t espnow_size = 250 / sizeof(DataReading);
uint8_t gatewayAddress[] = {MAC_PREFIX, GTWY_MAC};
-uint8_t gtwyAddress[] = {gatewayAddress[3], gatewayAddress[4], GTWY_MAC};
-uint8_t LoRaAddress[] = {0x42, 0x00};
+uint16_t gtwyAddress = ((gatewayAddress[4] << 8) | GTWY_MAC);
+uint16_t LoRaAddress = 0x4200;
+unsigned long transmitLoRaMsg = 0; // Number of total LoRa packets destined for us and of valid size
+unsigned long msgOkLoRa = 0; // Number of total LoRa packets with valid CRC
+
uint32_t wait_time = 0;
DataReading fdrsData[espnow_size];
@@ -196,16 +207,143 @@ void beginFDRS() {
#endif // USE_LORA
}
-void transmitLoRa(uint8_t* mac, DataReading * packet, uint8_t len) {
+// USED to get ACKs from LoRa gateway at this point. May be used in the future to get other data
+// Return type is crcResult struct - CRC_OK, CRC_BAD, CRC_NULL. CRC_NULL used for non-ack data
+crcResult getLoRa() {
+#ifdef USE_LORA
+ int packetSize = LoRa.parsePacket();
+ if ((packetSize - 6) % sizeof(SystemPacket) == 0 && packetSize > 0) { // packet size should be 6 bytes plus multiple of size of SystemPacket
+ uint8_t packet[packetSize];
+ uint16_t sourceMAC = 0x0000;
+ uint16_t destMAC = 0x0000;
+ uint16_t packetCRC = 0x0000; // CRC Extracted from received LoRa packet
+ uint16_t calcCRC = 0x0000; // CRC calculated from received LoRa packet
+ uint ln = (packetSize - 6) / sizeof(SystemPacket);
+ SystemPacket receiveData[ln];
+
+ LoRa.readBytes((uint8_t *)&packet, packetSize);
+
+ destMAC = (packet[0] << 8) | packet[1];
+ sourceMAC = (packet[2] << 8) | packet[3];
+ packetCRC = ((packet[packetSize - 2] << 8) | packet[packetSize - 1]);
+ DBG("Incoming LoRa. Size: " + String(packetSize) + " Bytes, RSSI: " + String(LoRa.packetRssi()) + "dBi, SNR: " + String(LoRa.packetSnr()) + "dB, PacketCRC: 0x" + String(packetCRC,16));
+ if (destMAC == LoRaAddress) {
+ //printLoraPacket(packet,sizeof(packet));
+ memcpy(receiveData, &packet[4], packetSize - 6); //Split off data portion of packet (N bytes)
+ if(ln == 1 && receiveData[0].cmd == cmd_ack) { // We have received an ACK packet
+ if(packetCRC == 0xFFFF) {
+ DBG("ACK Received - address 0x" + String(sourceMAC,16) + "(hex) does not want ACKs");
+ return CRC_OK;
+ }
+ else {
+ for(int i = 0; i < (packetSize - 2); i++) { // Last 2 bytes of packet are the CRC so do not include them in calculation
+ //printf("CRC: %02X : %d\n",calcCRC, i);
+ calcCRC = crc16_update(calcCRC, packet[i]);
+ }
+ if(calcCRC == packetCRC) {
+ DBG("ACK Received - CRC Match");
+ return CRC_OK;
+ }
+ else {
+ DBG("ACK Received CRC Mismatch! Packet CRC is 0x" + String(packetCRC,16) + ", Calculated CRC is 0x" + String(calcCRC,16));
+ return CRC_BAD;
+ }
+ }
+ }
+ else{ // data we have received is not of type ACK_T. How we handle is future enhancement.
+ DBG("Received some LoRa SystemPacket data that is not of type ACK. To be handled in future enhancement.");
+ DBG("ln: " + String(ln) + "data type: " + String(receiveData[0].cmd));
+ return CRC_NULL;
+ }
+ }
+ else if((packetSize - 6) % sizeof(DataReading) == 0) { // packet size should be 6 bytes plus multiple of size of DataReading)
+ DBG("Incoming LoRa packet of " + String(packetSize) + " bytes received, with DataReading data to be processed.");
+ return CRC_NULL;
+ }
+ else {
+ DBG("Incoming LoRa packet of " + String(packetSize) + " bytes received, not destined to our address.");
+ return CRC_NULL;
+ }
+ }
+ else {
+ if(packetSize != 0) {
+ DBG("Incoming LoRa packet of " + String(packetSize) + " bytes received");
+ }
+ }
+return CRC_NULL;
+#endif
+}
+
+void printLoraPacket(uint8_t* p,int size) {
+ printf("Printing packet of size %d.",size);
+ for(int i = 0; i < size; i++ ) {
+ if(i % 2 == 0) printf("\n%02d: ", i);
+ printf("%02X ", p[i]);
+ }
+ printf("\n");
+}
+
+void transmitLoRa(uint16_t* destMAC, DataReading * packet, uint8_t len) {
#ifdef USE_LORA
- uint8_t pkt[5 + (len * sizeof(DataReading))];
- memcpy(&pkt, mac, 3); //
- memcpy(&pkt[3], &LoRaAddress, 2);
- memcpy(&pkt[5], packet, len * sizeof(DataReading));
+ uint8_t pkt[6 + (len * sizeof(DataReading))];
+ uint16_t calcCRC = 0x0000;
+
+ pkt[0] = (*destMAC >> 8);
+ pkt[1] = (*destMAC & 0x00FF);
+ pkt[2] = (LoRaAddress >> 8);
+ pkt[3] = (LoRaAddress & 0x00FF);
+ memcpy(&pkt[4], packet, len * sizeof(DataReading));
+#ifdef LORA_ACK
+ for(int i = 0; i < (sizeof(pkt) - 2); i++) { // Last 2 bytes are CRC so do not include them in the calculation itself
+ //printf("CRC: %02X : %d\n",calcCRC, i);
+ calcCRC = crc16_update(calcCRC, pkt[i]);
+ }
+#else
+ calcCRC = LORA_NOACK_CRC;
+#endif // LORA_ACK
+ pkt[len * sizeof(DataReading) + 4] = (calcCRC >> 8);
+ pkt[len * sizeof(DataReading) + 5] = (calcCRC & 0x00FF);
+#ifdef LORA_ACK // Wait for ACK
+ int retries = LORA_RETRIES + 1;
+ while(retries != 0) {
+ if(transmitLoRaMsg != 0)
+ DBG("Transmitting LoRa message of size " + String(sizeof(pkt)) + " bytes with CRC 0x" + String(calcCRC,16) + " to gateway 0x" + String(*destMAC,16) + ". Retries remaining: " + String(retries - 1) + ", CRC OK " + String((float)msgOkLoRa/transmitLoRaMsg*100) + "%");
+ else
+ DBG("Transmitting LoRa message of size " + String(sizeof(pkt)) + " bytes with CRC 0x" + String(calcCRC,16) + " to gateway 0x" + String(*destMAC,16) + ". Retries remaining: " + String(retries - 1));
+ //printLoraPacket(pkt,sizeof(pkt));
+ LoRa.beginPacket();
+ LoRa.write((uint8_t*)&pkt, sizeof(pkt));
+ LoRa.endPacket();
+ transmitLoRaMsg++;
+ unsigned long loraAckTimeout = millis() + LORA_ACK_TIMEOUT;
+ retries--;
+ delay(10);
+ while(returnCRC == CRC_NULL && (millis() < loraAckTimeout)) {
+ returnCRC = getLoRa();
+ }
+ if(returnCRC == CRC_OK) {
+ //DBG("LoRa ACK Received! CRC OK");
+ msgOkLoRa++;
+ return; // we're done
+ }
+ else if(returnCRC == CRC_BAD) {
+ //DBG("LoRa ACK Received! CRC BAD");
+ // Resend original packet again if retries are available
+ }
+ else {
+ DBG("LoRa Timeout waiting for ACK!");
+ // resend original packet again if retries are available
+ }
+ }
+#else // Send and do not wait for ACK reply
+ DBG("Transmitting LoRa message of size " + String(sizeof(pkt)) + " bytes with CRC 0x" + String(calcCRC,16) + " to gateway 0x" + String(*destMAC,16));
+ //printLoraPacket(pkt,sizeof(pkt));
LoRa.beginPacket();
LoRa.write((uint8_t*)&pkt, sizeof(pkt));
LoRa.endPacket();
-#endif
+ transmitLoRaMsg++;
+#endif // LORA_ACK
+#endif // USE_LORA
}
void sendFDRS() {
@@ -216,10 +354,10 @@ void sendFDRS() {
DBG(" ESP-NOW sent.");
#endif
#ifdef USE_LORA
- transmitLoRa(gtwyAddress, fdrsData, data_count);
- DBG(" LoRa sent.");
+ transmitLoRa(>wyAddress, fdrsData, data_count);
#endif
data_count = 0;
+ returnCRC = CRC_NULL;
}
void loadFDRS(float d, uint8_t t) {
@@ -271,3 +409,31 @@ void pingFDRS(int timeout) {
DBG(" LoRa ping not sent because it isn't implemented.");
#endif
}
+
+// CRC16 from https://github.com/4-20ma/ModbusMaster/blob/3a05ff87677a9bdd8e027d6906dc05ca15ca8ade/src/util/crc16.h#L71
+
+/** @ingroup util_crc16
+ Processor-independent CRC-16 calculation.
+ Polynomial: x^16 + x^15 + x^2 + 1 (0xA001)
+ Initial value: 0xFFFF
+ This CRC is normally used in disk-drive controllers.
+ @param uint16_t crc (0x0000..0xFFFF)
+ @param uint8_t a (0x00..0xFF)
+ @return calculated CRC (0x0000..0xFFFF)
+*/
+
+static uint16_t crc16_update(uint16_t crc, uint8_t a)
+{
+ int i;
+
+ crc ^= a;
+ for (i = 0; i < 8; ++i)
+ {
+ if (crc & 1)
+ crc = (crc >> 1) ^ 0xA001;
+ else
+ crc = (crc >> 1);
+ }
+
+ return crc;
+}
\ No newline at end of file
diff --git a/FDRS_Sensor/fdrs_sensor_config.h b/FDRS_Sensor/fdrs_sensor_config.h
index 0aae313..c7395c5 100644
--- a/FDRS_Sensor/fdrs_sensor_config.h
+++ b/FDRS_Sensor/fdrs_sensor_config.h
@@ -26,5 +26,9 @@
//433E6 for Asia
//866E6 for Europe
//915E6 for North America
-//#define LORA_BAND 915E6
-//#define LORA_SF 7
+#define LORA_BAND 915E6
+#define LORA_SF 7
+#define LORA_ACK // Uncomment to enable request for LoRa ACKs at cost of increased battery usage
+#define LORA_NOACK_CRC 0xFFFF // CRC value to be used when ACKs are disabled to tell gateway we do not want ACK
+#define LORA_ACK_TIMEOUT 400 // ms timeout waiting for LoRa ACKs (if enabled). Wouldn't go less than 200ms
+#define LORA_RETRIES 2 // [0 - 3] When ACK enabled, number of sensor node tx retries when ACK not received or invalid CRC
diff --git a/examples/1_LoRa_Sensor/fdrs_sensor_config.h b/examples/1_LoRa_Sensor/fdrs_sensor_config.h
index f201831..12cea2e 100644
--- a/examples/1_LoRa_Sensor/fdrs_sensor_config.h
+++ b/examples/1_LoRa_Sensor/fdrs_sensor_config.h
@@ -25,5 +25,9 @@
//433E6 for Asia
//866E6 for Europe
//915E6 for North America
-//#define LORA_BAND 915E6
-//#define LORA_SF 7
+#define LORA_BAND 915E6
+#define LORA_SF 7
+#define LORA_ACK // Uncomment to enable request for LoRa ACKs at cost of increased battery usage
+#define LORA_NOACK_CRC 0xFFFF // CRC value to be used when ACKs are disabled to tell gateway we do not want ACK
+#define LORA_ACK_TIMEOUT 400 // ms timeout waiting for LoRa ACKs (if enabled). Wouldn't go less than 200ms
+#define LORA_RETRIES 2 // [0 - 3] When ACK enabled, number of sensor node tx retries when ACK not received or invalid CRC
diff --git a/examples/2_ESPNOW_Sensor/fdrs_sensor_config.h b/examples/2_ESPNOW_Sensor/fdrs_sensor_config.h
index 7be5afc..e356d8e 100644
--- a/examples/2_ESPNOW_Sensor/fdrs_sensor_config.h
+++ b/examples/2_ESPNOW_Sensor/fdrs_sensor_config.h
@@ -25,5 +25,9 @@
//433E6 for Asia
//866E6 for Europe
//915E6 for North America
-//#define LORA_BAND 915E6
-//#define LORA_SF 7
+#define LORA_BAND 915E6
+#define LORA_SF 7
+#define LORA_ACK // Uncomment to enable request for LoRa ACKs at cost of increased battery usage
+#define LORA_NOACK_CRC 0xFFFF // CRC value to be used when ACKs are disabled to tell gateway we do not want ACK
+#define LORA_ACK_TIMEOUT 400 // ms timeout waiting for LoRa ACKs (if enabled). Wouldn't go less than 200ms
+#define LORA_RETRIES 2 // [0 - 3] When ACK enabled, number of sensor node tx retries when ACK not received or invalid CRC
diff --git a/examples/ESPNOW_Stress_Test/fdrs_sensor_config.h b/examples/ESPNOW_Stress_Test/fdrs_sensor_config.h
index 649a341..ecba668 100644
--- a/examples/ESPNOW_Stress_Test/fdrs_sensor_config.h
+++ b/examples/ESPNOW_Stress_Test/fdrs_sensor_config.h
@@ -25,5 +25,9 @@
//433E6 for Asia
//866E6 for Europe
//915E6 for North America
-//#define LORA_BAND 915E6
-//#define LORA_SF 7
+#define LORA_BAND 915E6
+#define LORA_SF 7
+#define LORA_ACK // Uncomment to enable request for LoRa ACKs at cost of increased battery usage
+#define LORA_NOACK_CRC 0xFFFF // CRC value to be used when ACKs are disabled to tell gateway we do not want ACK
+#define LORA_ACK_TIMEOUT 400 // ms timeout waiting for LoRa ACKs (if enabled). Wouldn't go less than 200ms
+#define LORA_RETRIES 2 // [0 - 3] When ACK enabled, number of sensor node tx retries when ACK not received or invalid CRC
diff --git a/examples/Sensor_Examples/AHT20_fdrs/fdrs_sensor_config.h b/examples/Sensor_Examples/AHT20_fdrs/fdrs_sensor_config.h
index 1c08d6a..9944ae4 100644
--- a/examples/Sensor_Examples/AHT20_fdrs/fdrs_sensor_config.h
+++ b/examples/Sensor_Examples/AHT20_fdrs/fdrs_sensor_config.h
@@ -25,5 +25,9 @@
//433E6 for Asia
//866E6 for Europe
//915E6 for North America
-//#define LORA_BAND 915E6
-//#define LORA_SF 7
+#define LORA_BAND 915E6
+#define LORA_SF 7
+#define LORA_ACK // Uncomment to enable request for LoRa ACKs at cost of increased battery usage
+#define LORA_NOACK_CRC 0xFFFF // CRC value to be used when ACKs are disabled to tell gateway we do not want ACK
+#define LORA_ACK_TIMEOUT 400 // ms timeout waiting for LoRa ACKs (if enabled). Wouldn't go less than 200ms
+#define LORA_RETRIES 2 // [0 - 3] When ACK enabled, number of sensor node tx retries when ACK not received or invalid CRC
diff --git a/examples/Sensor_Examples/BME280_fdrs/fdrs_sensor_config.h b/examples/Sensor_Examples/BME280_fdrs/fdrs_sensor_config.h
index 1c08d6a..9944ae4 100644
--- a/examples/Sensor_Examples/BME280_fdrs/fdrs_sensor_config.h
+++ b/examples/Sensor_Examples/BME280_fdrs/fdrs_sensor_config.h
@@ -25,5 +25,9 @@
//433E6 for Asia
//866E6 for Europe
//915E6 for North America
-//#define LORA_BAND 915E6
-//#define LORA_SF 7
+#define LORA_BAND 915E6
+#define LORA_SF 7
+#define LORA_ACK // Uncomment to enable request for LoRa ACKs at cost of increased battery usage
+#define LORA_NOACK_CRC 0xFFFF // CRC value to be used when ACKs are disabled to tell gateway we do not want ACK
+#define LORA_ACK_TIMEOUT 400 // ms timeout waiting for LoRa ACKs (if enabled). Wouldn't go less than 200ms
+#define LORA_RETRIES 2 // [0 - 3] When ACK enabled, number of sensor node tx retries when ACK not received or invalid CRC
diff --git a/examples/Sensor_Examples/BMP280_fdrs/fdrs_sensor_config.h b/examples/Sensor_Examples/BMP280_fdrs/fdrs_sensor_config.h
index 1c08d6a..9944ae4 100644
--- a/examples/Sensor_Examples/BMP280_fdrs/fdrs_sensor_config.h
+++ b/examples/Sensor_Examples/BMP280_fdrs/fdrs_sensor_config.h
@@ -25,5 +25,9 @@
//433E6 for Asia
//866E6 for Europe
//915E6 for North America
-//#define LORA_BAND 915E6
-//#define LORA_SF 7
+#define LORA_BAND 915E6
+#define LORA_SF 7
+#define LORA_ACK // Uncomment to enable request for LoRa ACKs at cost of increased battery usage
+#define LORA_NOACK_CRC 0xFFFF // CRC value to be used when ACKs are disabled to tell gateway we do not want ACK
+#define LORA_ACK_TIMEOUT 400 // ms timeout waiting for LoRa ACKs (if enabled). Wouldn't go less than 200ms
+#define LORA_RETRIES 2 // [0 - 3] When ACK enabled, number of sensor node tx retries when ACK not received or invalid CRC
diff --git a/examples/Sensor_Examples/DHT22_fdrs/fdrs_sensor_config.h b/examples/Sensor_Examples/DHT22_fdrs/fdrs_sensor_config.h
index 1c08d6a..9944ae4 100644
--- a/examples/Sensor_Examples/DHT22_fdrs/fdrs_sensor_config.h
+++ b/examples/Sensor_Examples/DHT22_fdrs/fdrs_sensor_config.h
@@ -25,5 +25,9 @@
//433E6 for Asia
//866E6 for Europe
//915E6 for North America
-//#define LORA_BAND 915E6
-//#define LORA_SF 7
+#define LORA_BAND 915E6
+#define LORA_SF 7
+#define LORA_ACK // Uncomment to enable request for LoRa ACKs at cost of increased battery usage
+#define LORA_NOACK_CRC 0xFFFF // CRC value to be used when ACKs are disabled to tell gateway we do not want ACK
+#define LORA_ACK_TIMEOUT 400 // ms timeout waiting for LoRa ACKs (if enabled). Wouldn't go less than 200ms
+#define LORA_RETRIES 2 // [0 - 3] When ACK enabled, number of sensor node tx retries when ACK not received or invalid CRC
diff --git a/examples/Sensor_Examples/DS18B20_fdrs/fdrs_sensor_config.h b/examples/Sensor_Examples/DS18B20_fdrs/fdrs_sensor_config.h
index 1c08d6a..9944ae4 100644
--- a/examples/Sensor_Examples/DS18B20_fdrs/fdrs_sensor_config.h
+++ b/examples/Sensor_Examples/DS18B20_fdrs/fdrs_sensor_config.h
@@ -25,5 +25,9 @@
//433E6 for Asia
//866E6 for Europe
//915E6 for North America
-//#define LORA_BAND 915E6
-//#define LORA_SF 7
+#define LORA_BAND 915E6
+#define LORA_SF 7
+#define LORA_ACK // Uncomment to enable request for LoRa ACKs at cost of increased battery usage
+#define LORA_NOACK_CRC 0xFFFF // CRC value to be used when ACKs are disabled to tell gateway we do not want ACK
+#define LORA_ACK_TIMEOUT 400 // ms timeout waiting for LoRa ACKs (if enabled). Wouldn't go less than 200ms
+#define LORA_RETRIES 2 // [0 - 3] When ACK enabled, number of sensor node tx retries when ACK not received or invalid CRC
diff --git a/examples/Sensor_Examples/GenericGPS_fdrs/fdrs_sensor_config.h b/examples/Sensor_Examples/GenericGPS_fdrs/fdrs_sensor_config.h
index 1c08d6a..9944ae4 100644
--- a/examples/Sensor_Examples/GenericGPS_fdrs/fdrs_sensor_config.h
+++ b/examples/Sensor_Examples/GenericGPS_fdrs/fdrs_sensor_config.h
@@ -25,5 +25,9 @@
//433E6 for Asia
//866E6 for Europe
//915E6 for North America
-//#define LORA_BAND 915E6
-//#define LORA_SF 7
+#define LORA_BAND 915E6
+#define LORA_SF 7
+#define LORA_ACK // Uncomment to enable request for LoRa ACKs at cost of increased battery usage
+#define LORA_NOACK_CRC 0xFFFF // CRC value to be used when ACKs are disabled to tell gateway we do not want ACK
+#define LORA_ACK_TIMEOUT 400 // ms timeout waiting for LoRa ACKs (if enabled). Wouldn't go less than 200ms
+#define LORA_RETRIES 2 // [0 - 3] When ACK enabled, number of sensor node tx retries when ACK not received or invalid CRC
diff --git a/examples/Sensor_Examples/LilyGo_HiGrow_32/fdrs_sensor_config.h b/examples/Sensor_Examples/LilyGo_HiGrow_32/fdrs_sensor_config.h
index 1c08d6a..9944ae4 100644
--- a/examples/Sensor_Examples/LilyGo_HiGrow_32/fdrs_sensor_config.h
+++ b/examples/Sensor_Examples/LilyGo_HiGrow_32/fdrs_sensor_config.h
@@ -25,5 +25,9 @@
//433E6 for Asia
//866E6 for Europe
//915E6 for North America
-//#define LORA_BAND 915E6
-//#define LORA_SF 7
+#define LORA_BAND 915E6
+#define LORA_SF 7
+#define LORA_ACK // Uncomment to enable request for LoRa ACKs at cost of increased battery usage
+#define LORA_NOACK_CRC 0xFFFF // CRC value to be used when ACKs are disabled to tell gateway we do not want ACK
+#define LORA_ACK_TIMEOUT 400 // ms timeout waiting for LoRa ACKs (if enabled). Wouldn't go less than 200ms
+#define LORA_RETRIES 2 // [0 - 3] When ACK enabled, number of sensor node tx retries when ACK not received or invalid CRC
diff --git a/examples/Sensor_Examples/MESB_fdrs/fdrs_sensor_config.h b/examples/Sensor_Examples/MESB_fdrs/fdrs_sensor_config.h
index 1c08d6a..9944ae4 100644
--- a/examples/Sensor_Examples/MESB_fdrs/fdrs_sensor_config.h
+++ b/examples/Sensor_Examples/MESB_fdrs/fdrs_sensor_config.h
@@ -25,5 +25,9 @@
//433E6 for Asia
//866E6 for Europe
//915E6 for North America
-//#define LORA_BAND 915E6
-//#define LORA_SF 7
+#define LORA_BAND 915E6
+#define LORA_SF 7
+#define LORA_ACK // Uncomment to enable request for LoRa ACKs at cost of increased battery usage
+#define LORA_NOACK_CRC 0xFFFF // CRC value to be used when ACKs are disabled to tell gateway we do not want ACK
+#define LORA_ACK_TIMEOUT 400 // ms timeout waiting for LoRa ACKs (if enabled). Wouldn't go less than 200ms
+#define LORA_RETRIES 2 // [0 - 3] When ACK enabled, number of sensor node tx retries when ACK not received or invalid CRC
diff --git a/examples/Sensor_Examples/TippingBucket/fdrs_sensor_config.h b/examples/Sensor_Examples/TippingBucket/fdrs_sensor_config.h
index 1c08d6a..9944ae4 100644
--- a/examples/Sensor_Examples/TippingBucket/fdrs_sensor_config.h
+++ b/examples/Sensor_Examples/TippingBucket/fdrs_sensor_config.h
@@ -25,5 +25,9 @@
//433E6 for Asia
//866E6 for Europe
//915E6 for North America
-//#define LORA_BAND 915E6
-//#define LORA_SF 7
+#define LORA_BAND 915E6
+#define LORA_SF 7
+#define LORA_ACK // Uncomment to enable request for LoRa ACKs at cost of increased battery usage
+#define LORA_NOACK_CRC 0xFFFF // CRC value to be used when ACKs are disabled to tell gateway we do not want ACK
+#define LORA_ACK_TIMEOUT 400 // ms timeout waiting for LoRa ACKs (if enabled). Wouldn't go less than 200ms
+#define LORA_RETRIES 2 // [0 - 3] When ACK enabled, number of sensor node tx retries when ACK not received or invalid CRC
diff --git a/fdrs_sensor.h b/fdrs_sensor.h
index 48c2d32..88979ff 100644
--- a/fdrs_sensor.h
+++ b/fdrs_sensor.h
@@ -57,10 +57,27 @@ typedef struct __attribute__((packed)) DataReading {
} DataReading;
+
+enum crcResult{
+ CRC_NULL,
+ CRC_OK,
+ CRC_BAD,
+} returnCRC;
+
+enum {
+ cmd_clear,
+ cmd_ping,
+ cmd_add,
+ cmd_ack,
+};
+
const uint16_t espnow_size = 250 / sizeof(DataReading);
uint8_t gatewayAddress[] = {MAC_PREFIX, GTWY_MAC};
-uint8_t gtwyAddress[] = {gatewayAddress[3], gatewayAddress[4], GTWY_MAC};
-uint8_t LoRaAddress[] = {0x42, 0x00};
+uint16_t gtwyAddress = ((gatewayAddress[4] << 8) | GTWY_MAC);
+uint16_t LoRaAddress = 0x4200;
+unsigned long transmitLoRaMsg = 0; // Number of total LoRa packets destined for us and of valid size
+unsigned long msgOkLoRa = 0; // Number of total LoRa packets with valid CRC
+
uint32_t wait_time = 0;
DataReading fdrsData[espnow_size];
@@ -159,16 +176,143 @@ void beginFDRS() {
#endif // USE_LORA
}
-void transmitLoRa(uint8_t* mac, DataReading * packet, uint8_t len) {
+// USED to get ACKs from LoRa gateway at this point. May be used in the future to get other data
+// Return type is crcResult struct - CRC_OK, CRC_BAD, CRC_NULL. CRC_NULL used for non-ack data
+crcResult getLoRa() {
+#ifdef USE_LORA
+ int packetSize = LoRa.parsePacket();
+ if ((packetSize - 6) % sizeof(SystemPacket) == 0 && packetSize > 0) { // packet size should be 6 bytes plus multiple of size of SystemPacket
+ uint8_t packet[packetSize];
+ uint16_t sourceMAC = 0x0000;
+ uint16_t destMAC = 0x0000;
+ uint16_t packetCRC = 0x0000; // CRC Extracted from received LoRa packet
+ uint16_t calcCRC = 0x0000; // CRC calculated from received LoRa packet
+ uint ln = (packetSize - 6) / sizeof(SystemPacket);
+ SystemPacket receiveData[ln];
+
+ LoRa.readBytes((uint8_t *)&packet, packetSize);
+
+ destMAC = (packet[0] << 8) | packet[1];
+ sourceMAC = (packet[2] << 8) | packet[3];
+ packetCRC = ((packet[packetSize - 2] << 8) | packet[packetSize - 1]);
+ DBG("Incoming LoRa. Size: " + String(packetSize) + " Bytes, RSSI: " + String(LoRa.packetRssi()) + "dBi, SNR: " + String(LoRa.packetSnr()) + "dB, PacketCRC: 0x" + String(packetCRC,16));
+ if (destMAC == LoRaAddress) {
+ //printLoraPacket(packet,sizeof(packet));
+ memcpy(receiveData, &packet[4], packetSize - 6); //Split off data portion of packet (N bytes)
+ if(ln == 1 && receiveData[0].cmd == cmd_ack) { // We have received an ACK packet
+ if(packetCRC == 0xFFFF) {
+ DBG("ACK Received - address 0x" + String(sourceMAC,16) + "(hex) does not want ACKs");
+ return CRC_OK;
+ }
+ else {
+ for(int i = 0; i < (packetSize - 2); i++) { // Last 2 bytes of packet are the CRC so do not include them in calculation
+ //printf("CRC: %02X : %d\n",calcCRC, i);
+ calcCRC = crc16_update(calcCRC, packet[i]);
+ }
+ if(calcCRC == packetCRC) {
+ DBG("ACK Received - CRC Match");
+ return CRC_OK;
+ }
+ else {
+ DBG("ACK Received CRC Mismatch! Packet CRC is 0x" + String(packetCRC,16) + ", Calculated CRC is 0x" + String(calcCRC,16));
+ return CRC_BAD;
+ }
+ }
+ }
+ else{ // data we have received is not of type ACK_T. How we handle is future enhancement.
+ DBG("Received some LoRa SystemPacket data that is not of type ACK. To be handled in future enhancement.");
+ DBG("ln: " + String(ln) + "data type: " + String(receiveData[0].cmd));
+ return CRC_NULL;
+ }
+ }
+ else if((packetSize - 6) % sizeof(DataReading) == 0) { // packet size should be 6 bytes plus multiple of size of DataReading)
+ DBG("Incoming LoRa packet of " + String(packetSize) + " bytes received, with DataReading data to be processed.");
+ return CRC_NULL;
+ }
+ else {
+ DBG("Incoming LoRa packet of " + String(packetSize) + " bytes received, not destined to our address.");
+ return CRC_NULL;
+ }
+ }
+ else {
+ if(packetSize != 0) {
+ DBG("Incoming LoRa packet of " + String(packetSize) + " bytes received");
+ }
+ }
+return CRC_NULL;
+#endif
+}
+
+void printLoraPacket(uint8_t* p,int size) {
+ printf("Printing packet of size %d.",size);
+ for(int i = 0; i < size; i++ ) {
+ if(i % 2 == 0) printf("\n%02d: ", i);
+ printf("%02X ", p[i]);
+ }
+ printf("\n");
+}
+
+void transmitLoRa(uint16_t* destMAC, DataReading * packet, uint8_t len) {
#ifdef USE_LORA
- uint8_t pkt[5 + (len * sizeof(DataReading))];
- memcpy(&pkt, mac, 3); //
- memcpy(&pkt[3], &LoRaAddress, 2);
- memcpy(&pkt[5], packet, len * sizeof(DataReading));
+ uint8_t pkt[6 + (len * sizeof(DataReading))];
+ uint16_t calcCRC = 0x0000;
+
+ pkt[0] = (*destMAC >> 8);
+ pkt[1] = (*destMAC & 0x00FF);
+ pkt[2] = (LoRaAddress >> 8);
+ pkt[3] = (LoRaAddress & 0x00FF);
+ memcpy(&pkt[4], packet, len * sizeof(DataReading));
+#ifdef LORA_ACK
+ for(int i = 0; i < (sizeof(pkt) - 2); i++) { // Last 2 bytes are CRC so do not include them in the calculation itself
+ //printf("CRC: %02X : %d\n",calcCRC, i);
+ calcCRC = crc16_update(calcCRC, pkt[i]);
+ }
+#else
+ calcCRC = LORA_NOACK_CRC;
+#endif // LORA_ACK
+ pkt[len * sizeof(DataReading) + 4] = (calcCRC >> 8);
+ pkt[len * sizeof(DataReading) + 5] = (calcCRC & 0x00FF);
+#ifdef LORA_ACK // Wait for ACK
+ int retries = LORA_RETRIES + 1;
+ while(retries != 0) {
+ if(transmitLoRaMsg != 0)
+ DBG("Transmitting LoRa message of size " + String(sizeof(pkt)) + " bytes with CRC 0x" + String(calcCRC,16) + " to gateway 0x" + String(*destMAC,16) + ". Retries remaining: " + String(retries - 1) + ", CRC OK " + String((float)msgOkLoRa/transmitLoRaMsg*100) + "%");
+ else
+ DBG("Transmitting LoRa message of size " + String(sizeof(pkt)) + " bytes with CRC 0x" + String(calcCRC,16) + " to gateway 0x" + String(*destMAC,16) + ". Retries remaining: " + String(retries - 1));
+ //printLoraPacket(pkt,sizeof(pkt));
+ LoRa.beginPacket();
+ LoRa.write((uint8_t*)&pkt, sizeof(pkt));
+ LoRa.endPacket();
+ transmitLoRaMsg++;
+ unsigned long loraAckTimeout = millis() + LORA_ACK_TIMEOUT;
+ retries--;
+ delay(10);
+ while(returnCRC == CRC_NULL && (millis() < loraAckTimeout)) {
+ returnCRC = getLoRa();
+ }
+ if(returnCRC == CRC_OK) {
+ //DBG("LoRa ACK Received! CRC OK");
+ msgOkLoRa++;
+ return; // we're done
+ }
+ else if(returnCRC == CRC_BAD) {
+ //DBG("LoRa ACK Received! CRC BAD");
+ // Resend original packet again if retries are available
+ }
+ else {
+ DBG("LoRa Timeout waiting for ACK!");
+ // resend original packet again if retries are available
+ }
+ }
+#else // Send and do not wait for ACK reply
+ DBG("Transmitting LoRa message of size " + String(sizeof(pkt)) + " bytes with CRC 0x" + String(calcCRC,16) + " to gateway 0x" + String(*destMAC,16));
+ //printLoraPacket(pkt,sizeof(pkt));
LoRa.beginPacket();
LoRa.write((uint8_t*)&pkt, sizeof(pkt));
LoRa.endPacket();
-#endif
+ transmitLoRaMsg++;
+#endif // LORA_ACK
+#endif // USE_LORA
}
void sendFDRS() {
@@ -183,6 +327,7 @@ void sendFDRS() {
DBG(" LoRa sent.");
#endif
data_count = 0;
+ returnCRC = CRC_NULL;
}
void loadFDRS(float d, uint8_t t) {
@@ -211,3 +356,32 @@ void sleepFDRS(int sleep_time) {
DBG(" Delaying.");
delay(sleep_time * 1000);
}
+
+
+// CRC16 from https://github.com/4-20ma/ModbusMaster/blob/3a05ff87677a9bdd8e027d6906dc05ca15ca8ade/src/util/crc16.h#L71
+
+/** @ingroup util_crc16
+ Processor-independent CRC-16 calculation.
+ Polynomial: x^16 + x^15 + x^2 + 1 (0xA001)
+ Initial value: 0xFFFF
+ This CRC is normally used in disk-drive controllers.
+ @param uint16_t crc (0x0000..0xFFFF)
+ @param uint8_t a (0x00..0xFF)
+ @return calculated CRC (0x0000..0xFFFF)
+*/
+
+static uint16_t crc16_update(uint16_t crc, uint8_t a)
+{
+ int i;
+
+ crc ^= a;
+ for (i = 0; i < 8; ++i)
+ {
+ if (crc & 1)
+ crc = (crc >> 1) ^ 0xA001;
+ else
+ crc = (crc >> 1);
+ }
+
+ return crc;
+}
\ No newline at end of file