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Node / ReticulumProjects / RNode_Firmware.git / commits / 3ae8982


Commit 3ae8982e93a05f0d2a16944b8e3acc2c46f62f29

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Parents : 4bdd30d
Author : Mark Qvist <mark@unsigned.io>
Date : 2025-01-16T23:33:49+01:00

False preamble detection on SX1262

Changes

1 files changed, 15 insertions(+), 9 deletions(-)

M sx126x.cpp +15 -9

Diff

diff --git a/sx126x.cpp b/sx126x.cpp
index 79bb8e7..4c06862 100644
--- a/sx126x.cpp
+++ b/sx126x.cpp
@@ -390,29 +390,35 @@ int sx126x::endPacket() {
}
unsigned long preamble_detected_at = 0;
-unsigned long header_detected_at = 0;
extern long lora_preamble_time_ms;
extern long lora_header_time_ms;
+bool false_preamble_detected = false;
+
bool sx126x::dcd() {
- bool carrier_detected = false;
uint8_t buf[2] = {0}; executeOpcodeRead(OP_GET_IRQ_STATUS_6X, buf, 2);
+ uint32_t now = millis();
+
+ bool header_detected = false;
+ bool carrier_detected = false;
+
+ if ((buf[1] & IRQ_HEADER_DET_MASK_6X) != 0) { header_detected = true; carrier_detected = true; }
+ else { header_detected = false; }
if ((buf[1] & IRQ_PREAMBLE_DET_MASK_6X) != 0) {
carrier_detected = true;
- if (preamble_detected_at == 0) preamble_detected_at = millis();
- if (millis() - preamble_detected_at > lora_preamble_time_ms + lora_header_time_ms) {
+ if (preamble_detected_at == 0) { preamble_detected_at = now; }
+ if (now - preamble_detected_at > lora_preamble_time_ms + lora_header_time_ms) {
preamble_detected_at = 0;
+ if (!header_detected) { false_preamble_detected = true; }
uint8_t clearbuf[2] = {0};
clearbuf[1] = IRQ_PREAMBLE_DET_MASK_6X;
executeOpcode(OP_CLEAR_IRQ_STATUS_6X, clearbuf, 2);
}
}
- if ((buf[1] & IRQ_HEADER_DET_MASK_6X) != 0) {
- carrier_detected = true;
- header_detected_at = millis();
- }
-
+ // TODO: Maybe there's a way of unlatching the RSSI
+ // status without re-activating receive mode?
+ if (false_preamble_detected) { sx126x_modem.receive(); false_preamble_detected = false; }
return carrier_detected;
}


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