diff --git a/IMU.cpp b/IMU.cpp
index c36e032..fd10b6c 100644
--- a/IMU.cpp
+++ b/IMU.cpp
@@ -329,28 +329,29 @@ void imuInit()
         }
     }
 
-    // Put sensor in a known state before switching to continuous mode.
+    // Datasheet §6: must transition through power-down before setting any
+    // measurement mode.  No DRDY polling needed here — the main loop reads
+    // data continuously; we just need to get the mode register set.
     magnetometer_.initialize(AK09918_POWER_DOWN);
-    delay(10);  // datasheet: >=100µs after power-down; 10ms is safe
+    delay(10);
     magnetometer_.switchMode(AK09918_CONTINUOUS_100HZ);
+    // Wait 5 full sample periods (100 Hz → 10 ms each) so first data is ready.
+    delay(60);
 
-    // At 100 Hz the first sample takes ~10 ms. Poll ST1 with a delay
-    // instead of resetting on every attempt (reset clears the mode setting).
-    err = AK09918_ERR_NOT_RDY;
-    for (int retry_times = 0; retry_times < 20 && err != AK09918_ERR_OK; retry_times++) {
-        delay(15);  // wait one sample period (100Hz = 10ms) plus margin
-        err = magnetometer_.isDataReady();
-        if (err == AK09918_ERR_READ_FAILED) {
-            // I2C error – mode may have been lost, try re-applying it once.
-            Serial.printf("AK09918 I2C read failed on retry %d, re-applying mode...\n", retry_times + 1);
-            magnetometer_.switchMode(AK09918_CONTINUOUS_100HZ);
+    // Diagnostic: read ST1 and raw data to confirm the sensor is alive.
+    {
+        int16_t tx = 0, ty = 0, tz = 0;
+        const AK09918_err_type_t tErr = magnetometer_.getData(&tx, &ty, &tz);
+        const AK09918_err_type_t rdyErr = magnetometer_.isDataReady();
+        Serial.printf("AK09918 diag: getData err=%d x=%d y=%d z=%d  ST1_ready=%d\n",
+                      tErr, tx, ty, tz, rdyErr == AK09918_ERR_OK ? 1 : 0);
+        if (tErr == AK09918_ERR_OK || tErr == AK09918_ERR_OVERFLOW) {
+            Serial.println("AK09918 producing data.");
+        } else {
+            Serial.printf("AK09918 getData failed (err=%d). "
+                          "Sensor may be in power-down - check 3V3 supply.\n", tErr);
         }
     }
-    if (err == AK09918_ERR_OK) {
-        Serial.println("AK09918 ready.");
-    } else {
-        Serial.printf("AK09918 init timed out (last err=%d). Magnetometer will be unavailable.\n", err);
-    }
     // Serial.println("Start figure-8 calibration after 1 seconds.");
     // delay(1000);
     // calibrate(10000, &offset_x, &offset_y, &offset_z);