SX126x/8x: Also use PREAMBLE_DETECTED IRQ flag for actively receiving check (#2349)

* Use startReceive() instead of startReceiveDutyCycleAuto()

* Add preamble detected IRQ

* Escape from 'freeze' state when packet should have been received

* Use RADIOLIB_GODMODE for access to clearIrqStatus

* SX126x: Better handling of false preamble detections

* SX128x: Add preamble IRQ and false detection handling to active receiving check

* Remove unnecessary function declaration

---------

Co-authored-by: Ben Meadors <benmmeadors@gmail.com>
This commit is contained in:
GUVWAF 2023-03-11 19:59:29 +01:00 committed by GitHub
parent 9cadc0a16f
commit 6d443d2c67
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6 changed files with 59 additions and 12 deletions

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@ -471,6 +471,9 @@ void RadioInterface::applyModemConfig()
saveChannelNum(channel_num);
saveFreq(freq + loraConfig.frequency_offset);
preambleTimeMsec = getPacketTime((uint32_t)0);
maxPacketTimeMsec = getPacketTime(meshtastic_Constants_DATA_PAYLOAD_LEN + sizeof(PacketHeader));
LOG_INFO("Radio freq=%.3f, config.lora.frequency_offset=%.3f\n", freq, loraConfig.frequency_offset);
LOG_INFO("Set radio: region=%s, name=%s, config=%u, ch=%d, power=%d\n", myRegion->name, channelName, loraConfig.modem_preset,
channel_num, power);

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@ -63,7 +63,9 @@ class RadioInterface
- Tx/Rx turnaround time (maximum of SX126x and SX127x);
- MAC processing time (measured on T-beam) */
uint32_t slotTimeMsec = 8.5 * pow(2, sf) / bw + 0.2 + 0.4 + 7;
uint16_t preambleLength = 16; // 8 is default, but we use longer to increase the amount of sleep time when receiving
uint16_t preambleLength = 16; // 8 is default, but we use longer to increase the amount of sleep time when receiving
uint32_t preambleTimeMsec = 165; // calculated on startup, this is the default for LongFast
uint32_t maxPacketTimeMsec = 3246; // calculated on startup, this is the default for LongFast
const uint32_t PROCESSING_TIME_MSEC =
4500; // time to construct, process and construct a packet again (empirically determined)
const uint8_t CWmin = 2; // minimum CWsize

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@ -180,6 +180,7 @@ template <typename T> void SX126xInterface<T>::setStandby()
assert(err == RADIOLIB_ERR_NONE);
isReceiving = false; // If we were receiving, not any more
activeReceiveStart = 0;
disableInterrupt();
completeSending(); // If we were sending, not anymore
}
@ -213,9 +214,10 @@ template <typename T> void SX126xInterface<T>::startReceive()
setStandby();
// We use a 16 bit preamble so this should save some power by letting radio sit in standby mostly.
// Furthermore, we need the HEADER_VALID IRQ flag to detect whether we are actively receiving
int err =
lora.startReceiveDutyCycleAuto(preambleLength, 8, RADIOLIB_SX126X_IRQ_RX_DEFAULT | RADIOLIB_SX126X_IRQ_HEADER_VALID);
// Furthermore, we need the PREAMBLE_DETECTED and HEADER_VALID IRQ flag to detect whether we are actively receiving
int err = lora.startReceiveDutyCycleAuto(preambleLength, 8,
RADIOLIB_SX126X_IRQ_RX_DEFAULT | RADIOLIB_SX126X_IRQ_RADIOLIB_PREAMBLE_DETECTED |
RADIOLIB_SX126X_IRQ_HEADER_VALID);
assert(err == RADIOLIB_ERR_NONE);
isReceiving = true;
@ -248,10 +250,27 @@ template <typename T> bool SX126xInterface<T>::isActivelyReceiving()
// received and handled the interrupt for reading the packet/handling errors.
uint16_t irq = lora.getIrqStatus();
bool headerValid = (irq & RADIOLIB_SX126X_IRQ_HEADER_VALID);
bool detected = (irq & (RADIOLIB_SX126X_IRQ_HEADER_VALID | RADIOLIB_SX126X_IRQ_RADIOLIB_PREAMBLE_DETECTED));
// Handle false detections
if (detected) {
uint32_t now = millis();
if (!activeReceiveStart) {
activeReceiveStart = now;
} else if ((now - activeReceiveStart > 2 * preambleTimeMsec) && !(irq & RADIOLIB_SX126X_IRQ_HEADER_VALID)) {
// The HEADER_VALID flag should be set by now if it was really a packet, so ignore PREAMBLE_DETECTED flag
activeReceiveStart = 0;
LOG_DEBUG("Ignore false preamble detection.\n");
return false;
} else if (now - activeReceiveStart > maxPacketTimeMsec) {
// We should have gotten an RX_DONE IRQ by now if it was really a packet, so ignore HEADER_VALID flag
activeReceiveStart = 0;
LOG_DEBUG("Ignore false header detection.\n");
return false;
}
}
// if (headerValid) LOG_DEBUG("rx headerValid\n");
return headerValid;
// if (detected) LOG_DEBUG("rx detected\n");
return detected;
}
template <typename T> bool SX126xInterface<T>::sleep()

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@ -68,4 +68,5 @@ template <class T> class SX126xInterface : public RadioLibInterface
virtual void setStandby() override;
private:
uint32_t activeReceiveStart = 0;
};

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@ -157,6 +157,7 @@ template <typename T> void SX128xInterface<T>::setStandby()
#endif
isReceiving = false; // If we were receiving, not any more
activeReceiveStart = 0;
disableInterrupt();
completeSending(); // If we were sending, not anymore
}
@ -203,9 +204,10 @@ template <typename T> void SX128xInterface<T>::startReceive()
digitalWrite(SX128X_TXEN, LOW);
#endif
// We use the HEADER_VALID IRQ flag to detect whether we are actively receiving
int err =
lora.startReceive(RADIOLIB_SX128X_RX_TIMEOUT_INF, RADIOLIB_SX128X_IRQ_RX_DEFAULT | RADIOLIB_SX128X_IRQ_HEADER_VALID);
// We use the PREAMBLE_DETECTED and HEADER_VALID IRQ flag to detect whether we are actively receiving
int err = lora.startReceive(RADIOLIB_SX128X_RX_TIMEOUT_INF, RADIOLIB_SX128X_IRQ_RX_DEFAULT |
RADIOLIB_SX128X_IRQ_RADIOLIB_PREAMBLE_DETECTED |
RADIOLIB_SX128X_IRQ_HEADER_VALID);
assert(err == RADIOLIB_ERR_NONE);
@ -236,8 +238,27 @@ template <typename T> bool SX128xInterface<T>::isChannelActive()
template <typename T> bool SX128xInterface<T>::isActivelyReceiving()
{
uint16_t irq = lora.getIrqStatus();
bool hasHeader = (irq & RADIOLIB_SX128X_IRQ_HEADER_VALID);
return hasHeader;
bool detected = (irq & (RADIOLIB_SX128X_IRQ_HEADER_VALID | RADIOLIB_SX128X_IRQ_RADIOLIB_PREAMBLE_DETECTED));
// Handle false detections
if (detected) {
uint32_t now = millis();
if (!activeReceiveStart) {
activeReceiveStart = now;
} else if ((now - activeReceiveStart > 2 * preambleTimeMsec) && !(irq & RADIOLIB_SX128X_IRQ_HEADER_VALID)) {
// The HEADER_VALID flag should be set by now if it was really a packet, so ignore PREAMBLE_DETECTED flag
activeReceiveStart = 0;
LOG_DEBUG("Ignore false preamble detection.\n");
return false;
} else if (now - activeReceiveStart > maxPacketTimeMsec) {
// We should have gotten an RX_DONE IRQ by now if it was really a packet, so ignore HEADER_VALID flag
activeReceiveStart = 0;
LOG_DEBUG("Ignore false header detection.\n");
return false;
}
}
return detected;
}
template <typename T> bool SX128xInterface<T>::sleep()

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@ -68,4 +68,5 @@ template <class T> class SX128xInterface : public RadioLibInterface
virtual void setStandby() override;
private:
uint32_t activeReceiveStart = 0;
};