CLI: gps interval to set and persist the GPS read interval

docs/cli_commands.md

@@ -1010,6 +1010,20 @@ region save
 
 ---
 
+#### View or change the GPS read interval
+**Usage:**
+- `gps interval`
+- `gps interval <seconds>`
+
+**Parameters:**
+- `seconds`: seconds between location reads, `0` to `86400`. `0` restores the firmware default (1 s)
+
+**Default:** `0`
+
+**Note:** The bare form reports the stored value. The setting is persisted and re-applied at boot.
+
+---
+
 #### Sync this node's clock with GPS time
 **Usage:** 
 - `gps sync`

examples/simple_repeater/MyMesh.h

@@ -160,6 +160,11 @@ class MyMesh : public mesh::Mesh, public CommonCLICallbacks {
 #if ENV_INCLUDE_GPS == 1
   void applyGpsPrefs() {
     sensors.setSettingValue("gps", _prefs.gps_enabled?"1":"0");
+    if (_prefs.gps_interval > 0) {   // 0 = leave the firmware default (1 s)
+      char interval_str[12];   // max: 86400 seconds, 5 digits + null
+      sprintf(interval_str, "%u", (unsigned) _prefs.gps_interval);
+      sensors.setSettingValue("gps_interval", interval_str);
+    }
   }
 #endif
 

src/helpers/CommonCLI.cpp

@@ -19,6 +19,17 @@ static uint32_t _atoi(const char* sp) {
   return n;
 }
 
+// _atoi() returns 0 for garbage input, same as for a real "0" -- callers that
+// need to tell "you typed 0" from "you typed a typo" check the string first.
+static bool isAllDigits(const char* s) {
+  if (*s == 0) return false;
+  while (*s) {
+    if (*s < '0' || *s > '9') return false;
+    s++;
+  }
+  return true;
+}
+
 static bool isValidName(const char *n) {
   while (*n) {
     if (*n == '[' || *n == ']' || *n == '\\' || *n == ':' || *n == ',' || *n == '?' || *n == '*') return false;
@@ -390,6 +401,36 @@ void CommonCLI::handleCommand(uint32_t sender_timestamp, char* command, char* re
       } else {
         strcpy(reply, "error");
       }
+    } else if (memcmp(command, "gps interval", 12) == 0
+               && (command[12] == 0 || command[12] == ' ')) {
+      // Seconds between location reads. 0 means "use the firmware default"
+      // (1 s), matching how applyGpsPrefs() interprets a zero pref.
+      //
+      // The prefix match needs the delimiter check: without it "gps intervalX"
+      // matches here and then parses command[13] -- past the 'X' -- as the
+      // argument, so a mistyped command silently sets the interval to 0 instead
+      // of falling through to the generic "gps" handler and being rejected.
+      const char* arg = &command[12];
+      while (*arg == ' ') arg++;
+      if (*arg == 0) {   // bare `gps interval` (or only trailing spaces): report
+        sprintf(reply, "> %u", (unsigned) _prefs->gps_interval);
+      } else if (!isAllDigits(arg)) {
+        // _atoi() would silently read a typo like "abc" as 0, resetting the
+        // pref to the firmware default instead of reporting the mistake.
+        strcpy(reply, "Error: interval must be a number of seconds");
+      } else {
+        char secs_str[12];
+        uint32_t secs = _atoi(arg);
+        if (secs > 86400) secs = 86400;   // cap at 24 hours
+        sprintf(secs_str, "%u", (unsigned) secs);
+        if (_sensors->setSettingValue("gps_interval", secs_str)) {
+          _prefs->gps_interval = secs;
+          savePrefs();
+          strcpy(reply, "ok");
+        } else {
+          strcpy(reply, "gps interval not found");
+        }
+      }
     } else if (memcmp(command, "gps", 3) == 0) {
       LocationProvider * l = _sensors->getLocationProvider();
       if (l != NULL) {

src/helpers/sensors/EnvironmentSensorManager.cpp

@@ -737,6 +737,19 @@ bool EnvironmentSensorManager::setSettingValue(const char* name, const char* val
     }
     return true;
   }
+  // Deliberately NOT enumerated by getNumSettings()/getSettingName()/
+  // getSettingValue() above, unlike "gps": those three also drive
+  // CMD_GET_CUSTOM_VARS's wire payload in every companion_radio build
+  // (examples/companion_radio/MyMesh.cpp, ui-tiny/ui-new UITask.cpp), so
+  // adding an entry there changes an embedded companion-app payload on every
+  // target that compiles ENV_INCLUDE_GPS. "gps_interval" stays
+  // settable-but-not-listed, same as before.
+  //
+  // Also deliberately NOT gated on gps_detected, unlike "gps": every
+  // example's applyGpsPrefs() calls this at boot regardless of whether GPS
+  // hardware was found (and CMD_SET_CUSTOM_VAR / CommonCLI's `gps interval`
+  // rely on that), so gating it would break persisting the interval pref on
+  // boards where no GPS was detected at boot.
   if (strcmp(name, "gps_interval") == 0) {
     uint32_t interval_seconds = atoi(value);
     gps_update_interval_sec = interval_seconds > 0 ? interval_seconds : 1;