switch defaults to sf7/cr5

releasenotes/RELEASE_NOTES_1.17.2-zephcore.md

@@ -7,10 +7,38 @@ A small release. Most of it is fixes, and a few of them only matter on specific
 > a **T1000-E** (temperature and light sensors work again), or **any repeater** (1.17.1 broke guest logins
 > without a password). Everyone else can wait for the next release.
 >
-> Upgrading from 1.17.1 is straightforward — your contacts, settings and phone pairing all survive.
+> Upgrading from 1.17.1 is straightforward — your contacts, settings and phone pairing all survive. Note
+> that the **factory default radio settings changed to SF7 / CR 4/5**; this affects fresh flashes and
+> factory resets only, never a node that already has settings.
 
 ---
 
+## New nodes start on SF7 / CR 4/5
+
+A node with no saved settings — freshly flashed, or after a factory reset — now comes up on
+**SF7, coding rate 4/5**. It was SF8 / 4/8. Frequency (869.618 MHz), bandwidth (62.5 kHz) and
+transmit power are unchanged.
+
+Hungary moved its mesh to these settings, and ZephCore is aimed mainly at Hungarian users, so this is
+now what a node uses out of the box. On SF7 / 4/5 a packet spends roughly a third of the time on air
+that it did on SF8 / 4/8, which leaves the channel free for far more traffic. The trade is a little
+less range on the weakest links.
+
+> [!IMPORTANT]
+> **Nodes that already have settings are not touched.** Upgrading to 1.17.2 leaves your frequency,
+> spreading factor, coding rate and power exactly as you set them. Nothing is rewritten and nothing
+> needs checking afterwards.
+
+> [!WARNING]
+> **A factory reset now leaves the node on SF7 / 4/5.** If your mesh still runs SF8 / 4/8, a node that
+> has been reset will not hear it and will not be heard — radios only talk to other radios using the
+> same settings. Put it back with `set radio 869.618,62.5,8,8` after a reset, or move the whole mesh to
+> SF7 / 4/5.
+
+To change a node already in service, use `set radio <freq>,<bw>,<sf>,<cr>` on a repeater (the four
+values are comma-separated, and it needs a reboot to apply), or the radio settings screen in the phone
+app for a companion.
+
 ## Commands to your own node get their tick straight away
 
 When you send a command to your node's own chat contact (the one named `v` plus your node name), the app

zephcore/Repeater_CLI_commands.md

@@ -184,7 +184,7 @@ Caveats: the `sys=` tally needs `CONFIG_ZEPHCORE_GPS_SAT_DIAG` (default on for r
 
 | Command | Description |
 |---------|-------------|
-| `tempradio <freq> <bw> <sf> <cr> <timeout_mins>` | Apply temporary radio parameters; automatically reverts after `timeout_mins`. Constraints: freq 150–2500 MHz, bw 7–500 kHz, sf 5–12, cr 5–8. Saved prefs are never mutated — concurrent `set` commands and reboots both restore the real saved values. |
+| `tempradio <freq>,<bw>,<sf>,<cr>,<timeout_mins>` | Apply temporary radio parameters; automatically reverts after `timeout_mins`. Constraints: freq 150–2500 MHz, bw 7–500 kHz, sf 5–12, cr 5–8. Saved prefs are never mutated — concurrent `set` commands and reboots both restore the real saved values. |
 
 ---
 
@@ -272,7 +272,7 @@ Changes are persisted immediately unless noted. Some require a reboot.
 |---------|-------------|-------------|
 | `set name <name>` | No `[ ] \ : , ? *` | Set node name |
 | `set repeat <on\|off>` | | Enable or disable packet forwarding |
-| `set radio <freq> <bw> <sf> <cr>` | freq 150–2500, bw 7–500, sf 5–12, cr 5–8 | Set radio params *(reboot required)* |
+| `set radio <freq>,<bw>,<sf>,<cr>` | freq 150–2500, bw 7–500, sf 5–12, cr 5–8 | **Comma-separated**, not space-separated — spaces parse as a single argument and the command is rejected. Set radio params *(reboot required)* |
 | `set freq <mhz>` | 150–2500 *(USB only)* | Set frequency alone *(reboot required)* |
 | `set tx <dbm>` | −9 to board max (default 30) | Set TX power |
 | `set lat <latitude>` | | Set stored latitude |

zephcore/app/ObserverMesh.cpp

@@ -54,9 +54,9 @@ void ObserverMesh::begin(RepeaterDataStore *store, struct ObserverCreds *creds)
 
 	/* Initialize prefs with observer-specific defaults */
 	initNodePrefs(&_prefs);
-	_prefs.cr           = 5;   /* CR 4/5 */
+	_prefs.cr           = 5;   /* CR 4/5 (same as initNodePrefs; kept explicit) */
 	_prefs.tx_power_dbm = 0;   /* observer never TXes anyway */
-	/* freq=869.618, bw=62.5, sf=8 already set by initNodePrefs */
+	/* freq=869.618, bw=62.5, sf=7 already set by initNodePrefs */
 
 	/* First boot has to be detected BEFORE loadPrefs(): the store is shared
 	 * with the repeater and its no-file branch re-runs initNodePrefs(), applies

zephcore/app/RepeaterDataStore.cpp

@@ -260,8 +260,8 @@ bool RepeaterDataStore::loadPrefs(NodePrefs& prefs) {
                 (double)prefs.freq, prefs.sf, (double)prefs.bw);
         prefs.freq = 869.618f;
         prefs.bw = 62.5f;
-        prefs.sf = 8;
-        prefs.cr = 8;
+        prefs.sf = 7;
+        prefs.cr = 5;
         prefs.tx_power_dbm = 22;
     }
     /* Everything else that came off flash — bounds, NaNs, and the char fields,

zephcore/app/main_observer.cpp

@@ -290,7 +290,7 @@ int main(void)
 {
 	/* Initialize radio prefs with observer-specific defaults */
 	initNodePrefs(&s_radio_prefs);
-	s_radio_prefs.cr           = 5;   /* CR 4/5 (initNodePrefs sets 8) */
+	s_radio_prefs.cr           = 5;   /* CR 4/5 (same as initNodePrefs; kept explicit) */
 	s_radio_prefs.tx_power_dbm = 0;   /* observer never TXes */
 	strncpy(s_radio_prefs.node_name, "Observer",
 		sizeof(s_radio_prefs.node_name) - 1);

zephcore/helpers/NodePrefs.h

@@ -276,8 +276,8 @@ static inline void initNodePrefs(NodePrefs* prefs) {
 	/* Radio params - MUST match LoRaConfig.h for interop with companion nodes */
 	prefs->freq = 869.618f;           // LoRaConfig::FREQ_HZ / 1000000.0
 	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)
+	prefs->sf = 7;                    // LoRaConfig::SPREADING_FACTOR
+	prefs->cr = 5;                    // CR 4/5 (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

zephcore/include/mesh/LoRaConfig.h

@@ -12,8 +12,8 @@ namespace mesh {
 struct LoRaConfig {
 	static constexpr uint32_t FREQ_HZ = 869618000;   /* MeshCore default channel (EU 869 MHz ISM) */
 	static constexpr uint16_t BANDWIDTH = 62;         /* BW_62_KHZ — MeshCore default */
-	static constexpr uint8_t SPREADING_FACTOR = 8;    /* SF8: balance of range vs airtime */
-	static constexpr uint8_t CODING_RATE = 8;         /* CR_4_8: max FEC */
+	static constexpr uint8_t SPREADING_FACTOR = 7;    /* SF7: HU regional default since 2026-08 */
+	static constexpr uint8_t CODING_RATE = 5;         /* CR_4_5: lowest overhead */
 	static constexpr uint16_t PREAMBLE_LEN = 16;      /* MeshCore default; longer aids RX sync */
 	static constexpr int8_t TX_POWER_DBM = 22;        /* SX1262 max */
 };