From 624fc3306cb46bd676e10becafb0b467ea8f652e Mon Sep 17 00:00:00 2001
From: liquidraver <504870+liquidraver@users.noreply.github.com>
Date: Thu, 30 Apr 2026 23:03:17 +0200
Subject: [PATCH] tune duty cycling

---
 zephcore/adapters/radio/LoRaRadioBase.cpp             | 5 ++++-
 zephcore/patches/zephyr/0003-lora-sx126x-native.patch | 6 +++---
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/zephcore/adapters/radio/LoRaRadioBase.cpp b/zephcore/adapters/radio/LoRaRadioBase.cpp
index 40bf76e..b98aaca 100644
--- a/zephcore/adapters/radio/LoRaRadioBase.cpp
+++ b/zephcore/adapters/radio/LoRaRadioBase.cpp
@@ -429,7 +429,10 @@ void LoRaRadioBase::startReceive()
 		uint8_t sf = (uint8_t)cfg.datarate;
 		uint32_t bw_hz = bandwidth_to_hz(cfg.bandwidth);
 		float bw_khz = (float)bw_hz / 1000.0f;
-		uint16_t preamble_len = cfg.preamble_len;
+		/*uint16_t preamble_len = cfg.preamble_len;
+		  Duty-cycle timing assumption only: keep windows compatible with
+		 * meshes that commonly transmit with a 16-symbol preamble. */
+		uint16_t preamble_len = 16;
 		uint16_t min_symbols = (sf >= 7) ? 8 : 12;
 		int16_t sleep_symbols = (int16_t)preamble_len -
 					(int16_t)min_symbols;
diff --git a/zephcore/patches/zephyr/0003-lora-sx126x-native.patch b/zephcore/patches/zephyr/0003-lora-sx126x-native.patch
index be09f11..4113acb 100644
--- a/zephcore/patches/zephyr/0003-lora-sx126x-native.patch
+++ b/zephcore/patches/zephyr/0003-lora-sx126x-native.patch
@@ -68,7 +68,7 @@ index 17689720dd2..09982dc2e70 100644
  		return -EINVAL;
  	}
 diff --git a/drivers/lora/native/sx126x/sx126x.c b/drivers/lora/native/sx126x/sx126x.c
-index 30243ba5dc7..3c8619ac262 100644
+index 30243ba5dc7..c5e346da139 100644
 --- a/drivers/lora/native/sx126x/sx126x.c
 +++ b/drivers/lora/native/sx126x/sx126x.c
 @@ -10,10 +10,16 @@
@@ -1111,7 +1111,7 @@ index 30243ba5dc7..3c8619ac262 100644
  };
  
  #ifdef CONFIG_PM_DEVICE
-@@ -1112,6 +1881,7 @@ static int sx126x_pm_action(const struct device *dev,
+@@ -1112,6 +1892,7 @@ static int sx126x_pm_action(const struct device *dev,
  static int sx126x_init(const struct device *dev)
  {
  	struct sx126x_data *data = dev->data;
@@ -1119,7 +1119,7 @@ index 30243ba5dc7..3c8619ac262 100644
  	int ret;
  
  	/* Initialize data structures */
-@@ -1121,9 +1891,25 @@ static int sx126x_init(const struct device *dev)
+@@ -1121,9 +1902,25 @@ static int sx126x_init(const struct device *dev)
  	k_msgq_init(&data->rx_msgq, (char *)&data->rx_result,
  		    sizeof(struct sx126x_rx_result), 1);
  	k_work_init(&data->irq_work, sx126x_irq_work_handler);