Default transmit duty cycle to 10% instead of 50%

docs/cli_commands.md

@@ -565,12 +565,14 @@ This document provides an overview of CLI commands that can be sent to MeshCore
 **Parameters:**
 - `value`: Duty cycle percentage (1-100)
 
-**Default:** `50%` (equivalent to airtime factor 1.0)
+**Default:** `10%` (equivalent to airtime factor 9.0), the ETSI EN 300 220-2 limit for the
+869.4-869.65 MHz sub-band that the default frequency uses. Builds for regions without a duty
+cycle limit can override this with the `MAX_DUTY_CYCLE` build flag.
 
 **Examples:**
 - `set dutycycle 100` — no duty cycle limit
-- `set dutycycle 50` — 50% duty cycle (default)
-- `set dutycycle 10` — 10% duty cycle
+- `set dutycycle 50` — 50% duty cycle
+- `set dutycycle 10` — 10% duty cycle (default)
 - `set dutycycle 1` — 1% duty cycle (strictest EU requirement)
 
 > **Note:** Added in firmware v1.15.0

examples/companion_radio/MyMesh.cpp

@@ -943,7 +943,7 @@ MyMesh::MyMesh(mesh::Radio &radio, mesh::RNG &rng, mesh::RTCClock &rtc, SimpleMe
   send_unscoped = false;
 
   // defaults
-  _prefs.airtime_factor = 1.0;
+  _prefs.airtime_factor = DEFAULT_AIRTIME_FACTOR;
   strcpy(_prefs.node_name, "NONAME");
   _prefs.freq = LORA_FREQ;
   _prefs.sf = LORA_SF;

examples/simple_repeater/MyMesh.cpp

@@ -887,7 +887,7 @@ MyMesh::MyMesh(mesh::MainBoard &board, mesh::Radio &radio, mesh::MillisecondCloc
 #endif
 
   // defaults
-  _prefs.airtime_factor = 1.0;
+  _prefs.airtime_factor = DEFAULT_AIRTIME_FACTOR;
   _prefs.rx_delay_base = 0.0f;   // turn off by default, was 10.0;
   _prefs.tx_delay_factor = 0.5f; // was 0.25f
   _prefs.direct_tx_delay_factor = 0.3f; // was 0.2

examples/simple_room_server/MyMesh.cpp

@@ -644,7 +644,7 @@ MyMesh::MyMesh(mesh::MainBoard &board, mesh::Radio &radio, mesh::MillisecondCloc
   recv_pkt_region = NULL;
 
   // defaults
-  _prefs.airtime_factor = 1.0;
+  _prefs.airtime_factor = DEFAULT_AIRTIME_FACTOR;
   _prefs.rx_delay_base = 0.0f;   // off by default, was 10.0
   _prefs.tx_delay_factor = 0.5f; // was 0.25f;
   _prefs.direct_tx_delay_factor = 0.2f; // was zero

examples/simple_secure_chat/main.cpp

@@ -285,7 +285,7 @@ class MyMesh : public BaseChatMesh, ContactVisitor {
   {
     // defaults
     memset(&_prefs, 0, sizeof(_prefs));
-    _prefs.airtime_factor = 1.0;
+    _prefs.airtime_factor = DEFAULT_AIRTIME_FACTOR;
     strcpy(_prefs.node_name, "NONAME");
     _prefs.freq = LORA_FREQ;
     _prefs.tx_power_dbm = LORA_TX_POWER;

examples/simple_sensor/SensorMesh.cpp

@@ -710,7 +710,7 @@ SensorMesh::SensorMesh(mesh::MainBoard& board, mesh::Radio& radio, mesh::Millise
   set_radio_at = revert_radio_at = 0;
 
   // defaults
-  _prefs.airtime_factor = 1.0;
+  _prefs.airtime_factor = DEFAULT_AIRTIME_FACTOR;
   _prefs.rx_delay_base =   0.0f;  // turn off by default, was 10.0;
   _prefs.tx_delay_factor = 0.5f;   // was 0.25f
   _prefs.direct_tx_delay_factor = 0.2f; // was zero

src/Dispatcher.cpp

@@ -32,7 +32,7 @@ void Dispatcher::begin() {
 }
 
 float Dispatcher::getAirtimeBudgetFactor() const {
-  return 1.0;
+  return DEFAULT_AIRTIME_FACTOR;
 }
 
 void Dispatcher::updateTxBudget() {

src/Dispatcher.h

@@ -6,6 +6,16 @@
 #include <Utils.h>
 #include <string.h>
 
+// Default transmit duty cycle limit, as a percentage of the duty cycle window.
+// 10% is the ETSI EN 300 220-2 limit for the 869.4-869.65 MHz sub-band, which is where
+// the default LORA_FREQ lives. Override per build for regions without a duty cycle limit.
+#ifndef MAX_DUTY_CYCLE
+  #define MAX_DUTY_CYCLE  10
+#endif
+
+// Airtime budget factor equivalent of MAX_DUTY_CYCLE (see CommonCLI 'set dutycycle')
+#define DEFAULT_AIRTIME_FACTOR  ((100.0f / (MAX_DUTY_CYCLE)) - 1.0f)
+
 namespace mesh {
 
 /**