time()]); // Keep only last 1000 samples per device if (count($telemetry[$deviceId]) > 1000) { $telemetry[$deviceId] = array_slice($telemetry[$deviceId], -1000); } file_put_contents($telemetryFile, json_encode($telemetry, JSON_PRETTY_PRINT)); echo json_encode(['status' => 'success']); exit; } echo json_encode(['status' => 'error', 'message' => 'Invalid data']); exit; } ?>