clamp TX on station G2, refactor "set af"

zephcore/Kconfig

@@ -256,6 +256,24 @@ config ZEPHCORE_RADIO_LR1110
 
 endchoice
 
+config ZEPHCORE_DEFAULT_TX_POWER_DBM
+	int "Default TX power (dBm)"
+	default 22
+	range -9 22
+	help
+	  Default SX1262 TX power in dBm for fresh devices (no saved prefs).
+	  Boards with external PA should set this lower to avoid overdriving.
+	  Example: Station G2 with 20dB PA gain uses 15 dBm (→ 35 dBm output).
+
+config ZEPHCORE_MAX_TX_POWER_DBM
+	int "Maximum TX power (dBm)"
+	default 22
+	range -9 22
+	help
+	  Hard cap on SX1262 TX power. The radio adapter clamps any value
+	  above this, protecting external PAs from damage.
+	  Example: Station G2 caps at 19 dBm to stay below PA P1dB (35 dBm).
+
 endmenu # Radio Configuration
 
 menu "Board Configuration"

zephcore/adapters/radio/LoRaRadioBase.cpp

@@ -186,6 +186,11 @@ void LoRaRadioBase::buildModemConfig(struct lora_modem_config &cfg, bool tx)
 	cfg.preamble_len = LoRaConfig::PREAMBLE_LEN;
 	cfg.tx_power = _prefs ? (int8_t)_prefs->tx_power_dbm
 			      : LoRaConfig::TX_POWER_DBM;
+#ifdef CONFIG_ZEPHCORE_MAX_TX_POWER_DBM
+	if (cfg.tx_power > CONFIG_ZEPHCORE_MAX_TX_POWER_DBM) {
+		cfg.tx_power = CONFIG_ZEPHCORE_MAX_TX_POWER_DBM;
+	}
+#endif
 	cfg.tx = tx;
 	cfg.iq_inverted = false;
 	cfg.public_network = false;

zephcore/boards/esp32/station_g2/board.conf

@@ -17,5 +17,11 @@ CONFIG_BT_DIS_MODEL_NUMBER_STR="BQ Station G2"
 # Radio type — SX1262 via Zephyr native LoRa driver
 CONFIG_ZEPHCORE_RADIO_NATIVE=y
 
+# TX power limits — Station G2 has ~20dB external PA.
+# Default 15 dBm → ~35 dBm output (P1dB point).
+# Cap at 19 dBm → ~39 dBm absolute max (matches Arduino MAX_LORA_TX_POWER).
+CONFIG_ZEPHCORE_DEFAULT_TX_POWER_DBM=15
+CONFIG_ZEPHCORE_MAX_TX_POWER_DBM=19
+
 # Flash size — 16MB (override Zephyr default)
 CONFIG_ESPTOOLPY_FLASHSIZE_16MB=y

zephcore/helpers/CommonCLI.cpp

@@ -111,6 +111,11 @@ void CommonCLI::loadPrefs(const char* path) {
     _prefs->sf = constrain(_prefs->sf, (uint8_t)5, (uint8_t)12);
     _prefs->cr = constrain(_prefs->cr, (uint8_t)5, (uint8_t)8);
     _prefs->tx_power_dbm = constrain(_prefs->tx_power_dbm, (uint8_t)1, (uint8_t)30);
+#ifdef CONFIG_ZEPHCORE_MAX_TX_POWER_DBM
+    if (_prefs->tx_power_dbm > CONFIG_ZEPHCORE_MAX_TX_POWER_DBM) {
+        _prefs->tx_power_dbm = (uint8_t)CONFIG_ZEPHCORE_MAX_TX_POWER_DBM;
+    }
+#endif
     _prefs->multi_acks = constrain(_prefs->multi_acks, (uint8_t)0, (uint8_t)1);
     _prefs->adc_multiplier = constrain(_prefs->adc_multiplier, 0.0f, 10.0f);
     _prefs->powersaving_enabled = constrain(_prefs->powersaving_enabled, (uint8_t)0, (uint8_t)1);
@@ -317,7 +322,8 @@ void CommonCLI::handleCommand(uint32_t sender_timestamp, const char* command, ch
     } else if (memcmp(command, "get ", 4) == 0) {
         const char* config = &command[4];
         if (memcmp(config, "af", 2) == 0) {
-            snprintf(reply, CLI_REPLY_SIZE, "> %.0f%%", (double)_prefs->airtime_factor);
+            int dc = (_prefs->airtime_factor == 0.0f) ? 100 : (int)_prefs->airtime_factor;
+            snprintf(reply, CLI_REPLY_SIZE, "> Duty Cycle: %d%%", dc);
         } else if (memcmp(config, "int.thresh", 10) == 0) {
             snprintf(reply, CLI_REPLY_SIZE, "> %u", (uint32_t)_prefs->interference_threshold);
         } else if (memcmp(config, "agc.reset.interval", 18) == 0) {
@@ -391,9 +397,15 @@ void CommonCLI::handleCommand(uint32_t sender_timestamp, const char* command, ch
     } else if (memcmp(command, "set ", 4) == 0) {
         const char* config = &command[4];
         if (memcmp(config, "af ", 3) == 0) {
-            _prefs->airtime_factor = atof(&config[3]);
+            int val = atoi(&config[3]);
+            if (val <= 0 || val >= 100) {
+                _prefs->airtime_factor = 0.0f;
+            } else {
+                _prefs->airtime_factor = (float)val;
+            }
             savePrefs();
-            strcpy(reply, "OK");
+            int dc = (_prefs->airtime_factor == 0.0f) ? 100 : (int)_prefs->airtime_factor;
+            snprintf(reply, CLI_REPLY_SIZE, "Duty Cycle set: %d%%", dc);
         } else if (memcmp(config, "int.thresh ", 11) == 0) {
             _prefs->interference_threshold = atoi(&config[11]);
             savePrefs();
@@ -532,10 +544,16 @@ void CommonCLI::handleCommand(uint32_t sender_timestamp, const char* command, ch
             savePrefs();
             strcpy(reply, "OK");
         } else if (memcmp(config, "tx ", 3) == 0) {
-            _prefs->tx_power_dbm = atoi(&config[3]);
+            int val = atoi(&config[3]);
+#ifdef CONFIG_ZEPHCORE_MAX_TX_POWER_DBM
+            if (val > CONFIG_ZEPHCORE_MAX_TX_POWER_DBM) {
+                val = CONFIG_ZEPHCORE_MAX_TX_POWER_DBM;
+            }
+#endif
+            _prefs->tx_power_dbm = (uint8_t)val;
             savePrefs();
             _callbacks->setTxPower(_prefs->tx_power_dbm);
-            strcpy(reply, "OK");
+            snprintf(reply, CLI_REPLY_SIZE, "OK - tx power=%u dBm", (uint32_t)_prefs->tx_power_dbm);
         } else if (sender_timestamp == 0 && memcmp(config, "freq ", 5) == 0) {
             _prefs->freq = atof(&config[5]);
             savePrefs();

zephcore/helpers/NodePrefs.h

@@ -90,7 +90,11 @@ static inline void initNodePrefs(NodePrefs* prefs) {
 	prefs->bw = 62.5f;                // LoRaConfig::BANDWIDTH
 	prefs->sf = 8;                    // LoRaConfig::SPREADING_FACTOR
 	prefs->cr = 8;                    // CR 4/8 (MeshCore uses 5-8 for CR 4/5 through 4/8)
+#ifdef CONFIG_ZEPHCORE_DEFAULT_TX_POWER_DBM
+	prefs->tx_power_dbm = CONFIG_ZEPHCORE_DEFAULT_TX_POWER_DBM;
+#else
 	prefs->tx_power_dbm = 22;         // LoRaConfig::TX_POWER_DBM
+#endif
 	prefs->disable_fwd = 0;
 	prefs->advert_interval = 60;      // 2 minutes (value / 2)
 	prefs->flood_advert_interval = 12; // 12 hours