diff --git a/bbn_wave_freq_m5atomS3/bbn_wave_freq_m5atomS3.ino b/bbn_wave_freq_m5atomS3/bbn_wave_freq_m5atomS3.ino
index 7eb03f6..b1e80c4 100644
--- a/bbn_wave_freq_m5atomS3/bbn_wave_freq_m5atomS3.ino
+++ b/bbn_wave_freq_m5atomS3/bbn_wave_freq_m5atomS3.ino
@@ -175,8 +175,8 @@ void repeatMe() {
     accel_rotated.y = rotated_a[1];
     accel_rotated.z = rotated_a[2];
 
-    //float a = (accel_rotated.z - 1.0);  // acceleration in fractions of g
-    float a = - 0.25 * PI * PI * sin(2 * PI * state.t * 0.25) / g_std; // dummy test data (amplitude of heave = 1m, 4sec - period)
+    float a = (accel_rotated.z - 1.0);  // acceleration in fractions of g
+    //float a = - 0.25 * PI * PI * sin(2 * PI * state.t * 0.25) / g_std; // dummy test data (amplitude of heave = 1m, 4sec - period)
 
     float speed_prev = waveState.vert_speed;
     kalman_wave_step(&waveState, a * g_std, delta_t);