Fix TX and RX operation using interrupt by modified _statusIrq to volatile

Author: chandrawi

examples/SX126x/SX126x_LoRa_receiver_continuous/SX126x_LoRa_receiver_continuous.ino

@@ -26,7 +26,7 @@ void setup() {
  LoRa.setFrequency(915000000);
 
  // Set RX gain to boosted gain
- Serial.println("Set RX gain to power saving gain");
+ Serial.println("Set RX gain to boosted gain");
  LoRa.setRxGain(SX126X_RX_GAIN_BOOSTED);
 
  // Configure modulation parameter including spreading factor (SF), bandwidth (BW), and coding rate (CR)

examples/SX126x/SX126x_LoRa_receiver_listen/SX126x_LoRa_receiver_listen.ino

@@ -26,7 +26,7 @@ void setup() {
  LoRa.setFrequency(915000000);
 
  // Set RX gain to boosted gain
- Serial.println("Set RX gain to power saving gain");
+ Serial.println("Set RX gain to boosted gain");
  LoRa.setRxGain(SX126X_RX_GAIN_BOOSTED);
 
  // Configure modulation parameter including spreading factor (SF), bandwidth (BW), and coding rate (CR)

examples/SX126x/SX126x_driver_rx/SX126x_driver_rx.ino

@@ -115,7 +115,7 @@ void settingFunction() {
  sx126x_writeRegister(SX126X_REG_LORA_SYNC_WORD_MSB, sw, 2);
 }
 
-uint16_t receiveFunction(char* msg, uint8_t &len, uint32_t timeout) {
+uint16_t receiveFunction(char* message, uint8_t &len, uint32_t timeout) {
 
  Serial.println("\n-- RECEIVE FUNCTION --");
 
@@ -162,7 +162,7 @@ uint16_t receiveFunction(char* msg, uint8_t &len, uint32_t timeout) {
  Serial.println("Get received length and buffer base address");
  uint8_t payloadLengthRx, rxStartBufferPointer;
  sx126x_getRxBufferStatus(&payloadLengthRx, &rxStartBufferPointer);
- uint8_t message[payloadLengthRx];
+ uint8_t msgUint8[payloadLengthRx];
 
  // Get and display packet status
  Serial.println("Get received packet status");
@@ -181,11 +181,11 @@ uint16_t receiveFunction(char* msg, uint8_t &len, uint32_t timeout) {
  // Read message from buffer
  Serial.println("Read message from buffer");
  Serial.print("Message in bytes : [ ");
- sx126x_readBuffer(rxStartBufferPointer, message, payloadLengthRx);
+ sx126x_readBuffer(rxStartBufferPointer, msgUint8, payloadLengthRx);
  len = payloadLengthRx;
  for (uint8_t i=0; i<len; i++){
- msg[i] = (char) message[i];
- Serial.print((uint8_t) message[i]);
+ message[i] = (char) msgUint8[i];
+ Serial.print(msgUint8[i]);
  Serial.print(" ");
  }
  Serial.println("]");
@@ -199,7 +199,7 @@ void setup() {
  // Begin serial communication
  Serial.begin(38400);
 
- // Seetings for LoRa communication
+ // Settings for LoRa communication
  settingFunction();
 }
 

examples/SX126x/SX126x_driver_tx/SX126x_driver_tx.ino

@@ -197,7 +197,7 @@ void setup() {
  // Begin serial communication
  Serial.begin(38400);
 
- // Seetings for LoRa communication
+ // Settings for LoRa communication
  settingFunction();
 }
 

examples/SX127x/SX127x_LoRa_receiver_callback/SX127x_LoRa_receiver_callback.ino

@@ -2,10 +2,10 @@
 
 SX127x LoRa;
 
-// receive data length and pointer
-const uint8_t packetLength = 15;
-uint8_t packetData[packetLength];
-volatile bool flag = false;
+// receive data container and length
+const uint8_t maxLength = 15;
+volatile uint8_t packetLength = 0;
+uint8_t packetData[maxLength];
 
 void setup() {
 
@@ -25,7 +25,7 @@ void setup() {
  LoRa.setFrequency(915E6);
 
  // Set RX gain to boosted gain
- Serial.println("Set RX gain to power saving gain");
+ Serial.println("Set RX gain to boosted gain");
  LoRa.setRxGain(SX127X_RX_GAIN_BOOSTED);
 
  // Configure modulation parameter including spreading factor (SF), bandwidth (BW), and coding rate (CR)
@@ -56,7 +56,7 @@ void setup() {
 
 void loop() {
 
- if (flag) {
+ if (packetLength) {
  // Print received package
  Serial.write(packetData, packetLength - 1);
  Serial.print(" ");
@@ -70,17 +70,18 @@ void loop() {
  Serial.println(" dB");
  Serial.println();
 
- // Reset flag
- flag = false;
+ // Reset receive data container length
+ packetLength = 0;
  }
 }
 
 void getReceiveData() {
 
- // set flag
- flag = true;
- // Store received data
- for (uint8_t i=0; i<packetLength; i++) {
- packetData[i] = LoRa.read();
+ // set received length
+ packetLength = LoRa.available();
+ if (packetLength > maxLength) {
+ packetLength = maxLength;
  }
+ // Store received data
+ LoRa.read(packetData, packetLength);
 }

examples/SX127x/SX127x_LoRa_receiver_timeout/SX127x_LoRa_receiver_timeout.ino

@@ -20,7 +20,7 @@ void setup() {
  LoRa.setFrequency(915E6);
 
  // Set RX gain to boosted gain
- Serial.println("Set RX gain to power saving gain");
+ Serial.println("Set RX gain to boosted gain");
  LoRa.setRxGain(SX127X_RX_GAIN_BOOSTED);
 
  // Configure modulation parameter including spreading factor (SF), bandwidth (BW), and coding rate (CR)

examples/SX127x/SX127x_LoRa_transmitter/SX127x_LoRa_transmitter.ino

@@ -29,8 +29,8 @@ void setup() {
  Serial.println("Set frequency to 915 Mhz");
  LoRa.setFrequency(915E6);
 
- // Set RX gain. RX gain option are power saving gain or boosted gain 
- Serial.println("Set RX gain to power saving gain");
+ // Set TX power, this function will set PA config with optimal setting for requested TX power
+ Serial.println("Set TX power to +17 dBm");
  LoRa.setTxPower(17, SX127X_TX_POWER_PA_BOOST); // TX power +17 dBm using PA boost pin
 
  // Configure modulation parameter including spreading factor (SF), bandwidth (BW), and coding rate (CR)

examples/SX127x/SX127x_driver_rx/SX127x_driver_rx.ino

@@ -1,7 +1,7 @@
 #include <SX127x_driver.h>
 
 // Pin setting
-int8_t nssPin = 10, resetPin = 9, irqPin = 2, rxenPin = 7, txenPin = 8;
+int8_t nssPin = 10, resetPin = 9, irqPin = 2, rxenPin = -1, txenPin = -1;
 
 // RF frequency setting
 uint32_t frequency = 915000000;
@@ -37,6 +37,10 @@ void settingFunction() {
  Serial.println("Setting pins");
  sx127x_setPins(nssPin);
  pinMode(irqPin, INPUT);
+ if (txenPin != -1 && rxenPin != -1) {
+ pinMode(txenPin, OUTPUT);
+ pinMode(rxenPin, OUTPUT);
+ }
 
  // Reset RF module by setting resetPin to LOW and begin SPI communication
  sx127x_reset(resetPin);
@@ -64,6 +68,15 @@ void settingFunction() {
  Serial.print(frequency / 1000000);
  Serial.println(" MHz");
 
+ // Set rx gain to selected gain
+ Serial.print("Set RX gain to ");
+ if (boost == SX127X_RX_GAIN_POWER_SAVING) Serial.println("power saving gain");
+ else if (boost == SX127X_RX_GAIN_BOOSTED) Serial.println("boosted gain");
+ uint8_t LnaBoostHf = boost ? 0x03 : 0x00;
+ uint8_t AgcOn = level == SX127X_RX_GAIN_AUTO ? 0x01 : 0x00;
+ sx127x_writeRegister(SX127X_REG_LNA, LnaBoostHf | (level << 5));
+ sx127x_writeBits(SX127X_REG_MODEM_CONFIG_3, AgcOn, 2, 1);
+
  // Set modulation param and packet param
  Serial.println("Set modulation with predefined parameters");
  Serial.println("Set packet with predefined parameters");
@@ -107,6 +120,12 @@ uint8_t receiveFunction(char* message, uint8_t &length) {
  Serial.println("Attach interrupt on IRQ pin");
  attachInterrupt(digitalPinToInterrupt(irqPin), checkReceiveDone, RISING);
 
+ // Set txen and rxen pin state for receiving packet
+ if (txenPin != -1 && rxenPin != -1) {
+ digitalWrite(txenPin, LOW);
+ digitalWrite(rxenPin, HIGH);
+ }
+
  // Receive message
  Serial.println("Receiving message...");
  sx127x_writeRegister(SX127X_REG_OP_MODE, SX127X_LORA_MODEM | SX127X_MODE_RX_CONTINUOUS);
@@ -126,6 +145,9 @@ uint8_t receiveFunction(char* message, uint8_t &length) {
  uint8_t irqStat = sx127x_readRegister(SX127X_REG_IRQ_FLAGS);
  sx127x_writeRegister(SX127X_REG_IRQ_FLAGS, SX127X_IRQ_RX_DONE);
  Serial.println("Clear IRQ status");
+ if (rxenPin != -1) {
+ digitalWrite(rxenPin, LOW);
+ }
 
  // Get FIFO address of received message and configure address pointer
  reg = sx127x_readRegister(SX127X_REG_FIFO_RX_CURRENT_ADDR);
@@ -140,6 +162,15 @@ uint8_t receiveFunction(char* message, uint8_t &length) {
  Serial.print(length);
  Serial.println(")");
 
+ // Get and display packet status
+ Serial.println("Get received packet status");
+ float rssi = ((int16_t) sx127x_readRegister(SX127X_REG_PKT_RSSI_VALUE) - SX127X_RSSI_OFFSET_HF);
+ float snr = (int8_t) sx127x_readRegister(SX127X_REG_PKT_SNR_VALUE) / 4.0;
+ Serial.print("Packet status: RSSI = ");
+ Serial.print(rssi);
+ Serial.print(" | SNR = ");
+ Serial.println(snr);
+
  // Read message from buffer
  Serial.print("Message in bytes : [ ");
  for (uint8_t i = 0; i < length; i++) {

examples/SX127x/SX127x_driver_tx/SX127x_driver_tx.ino

@@ -1,12 +1,13 @@
 #include <SX127x_driver.h>
 
 // Pin setting
-int8_t nssPin = 10, resetPin = 9, irqPin = 2, rxenPin = 7, txenPin = 8;
+int8_t nssPin = 10, resetPin = 9, irqPin = 2, rxenPin = -1, txenPin = -1;
 
 // RF frequency setting
 uint32_t frequency = 915000000;
 
 // PA and TX power setting
+uint8_t paConfig = 0xC0;
 uint8_t txPower = 17;
 uint8_t paPin = SX127X_TX_POWER_PA_BOOST;
 
@@ -37,6 +38,10 @@ void settingFunction() {
  Serial.println("Setting pins");
  sx127x_setPins(nssPin);
  pinMode(irqPin, INPUT);
+ if (txenPin != -1 && rxenPin != -1) {
+ pinMode(txenPin, OUTPUT);
+ pinMode(rxenPin, OUTPUT);
+ }
 
  // Reset RF module by setting resetPin to LOW and begin SPI communication
  sx127x_reset(resetPin);
@@ -64,6 +69,15 @@ void settingFunction() {
  Serial.print(frequency / 1000000);
  Serial.println(" MHz");
 
+ // Set tx power to selected TX power
+ Serial.print("Set TX power to ");
+ Serial.print(txPower, DEC);
+ Serial.println(" dBm");
+ uint8_t outputPower = txPower - 2;
+ uint8_t paDac = txPower > 17 ? 0x07 : 0x04;
+ sx127x_writeRegister(SX127X_REG_PA_DAC, paDac);
+ sx127x_writeRegister(SX127X_REG_PA_CONFIG, paConfig | outputPower);
+
  // Set modulation param and packet param
  Serial.println("Set modulation with predefined parameters");
  Serial.println("Set packet with predefined parameters");
@@ -137,6 +151,12 @@ uint8_t transmitFunction(char* message, uint8_t length) {
  Serial.println("Attach interrupt on IRQ pin");
  attachInterrupt(digitalPinToInterrupt(irqPin), checkTransmitDone, RISING);
 
+ // Set txen and rxen pin state for transmitting packet
+ if (txenPin != -1 && rxenPin != -1) {
+ digitalWrite(txenPin, HIGH);
+ digitalWrite(rxenPin, LOW);
+ }
+
  // Transmit message
  Serial.println("Transmitting message...");
  sx127x_writeRegister(SX127X_REG_OP_MODE, SX127X_LORA_MODEM | SX127X_MODE_TX);
@@ -159,6 +179,9 @@ uint8_t transmitFunction(char* message, uint8_t length) {
  uint8_t irqStat = sx127x_readRegister(SX127X_REG_IRQ_FLAGS);
  sx127x_writeRegister(SX127X_REG_IRQ_FLAGS, 0xFF);
  Serial.println("Clear IRQ status");
+ if (txenPin != -1) {
+ digitalWrite(txenPin, LOW);
+ }
 
  // return interrupt status
  return irqStat;

src/SX126x.cpp

@@ -4,7 +4,7 @@ void (*SX126x::_onTransmit)();
 
 void (*SX126x::_onReceive)();
 
-uint16_t SX126x::_statusIrq = 0xFFFF;
+volatile uint16_t SX126x::_statusIrq = 0xFFFF;
 
 uint32_t SX126x::_transmitTime = 0;
 
@@ -745,7 +745,9 @@ void SX126x::_interruptTx()
  detachInterrupt(_irqStatic);
 
  // store IRQ status
- sx126x_getIrqStatus(&_statusIrq);
+ uint16_t buf;
+ sx126x_getIrqStatus(&buf);
+ _statusIrq = buf;
 
  // call onTransmit function
  if (_onTransmit) {
@@ -761,7 +763,9 @@ void SX126x::_interruptRx()
  sx126x_fixRxTimeout();
 
  // store IRQ status
- sx126x_getIrqStatus(&_statusIrq);
+ uint16_t buf;
+ sx126x_getIrqStatus(&buf);
+ _statusIrq = buf;
 
  // get received payload length and buffer index
  sx126x_getRxBufferStatus(&_payloadTxRx, &_bufferIndex);
@@ -775,7 +779,9 @@ void SX126x::_interruptRx()
 void SX126x::_interruptRxContinuous()
 {
  // store IRQ status
- sx126x_getIrqStatus(&_statusIrq);
+ uint16_t buf;
+ sx126x_getIrqStatus(&buf);
+ _statusIrq = buf;
 
  // clear IRQ status
  sx126x_clearIrqStatus(0x03FF);