- const float lo_thr = min_v + (amplitude * 0.1); // 10% above min
- const float hi_thr = max_v - (amplitude * 0.1); // 10% below max
+ const float center = min_v + (amplitude / 2);
+ const float lo_thr = center - (amplitude * 0.15); // 15% margin
+ const float hi_thr = center + (amplitude * 0.15); // 15% margin