diff --git a/src/controller/ebike_app.c b/src/controller/ebike_app.c
index 7a048b06..afed4f55 100755
--- a/src/controller/ebike_app.c
+++ b/src/controller/ebike_app.c
@@ -766,7 +766,7 @@ static void ebike_control_motor(void)
 		
 		//voltage based control assumes the winding resistance is constant for simplicity
 		uint32_t smooth_start_voltage_target_x100 = (uint32_t)(uint16_t)(smooth_start_voltage_limit_x100 + smooth_start_voltage_limit_blend_x100);
-		smooth_start_voltage_target_x100 += (uint32_t)(uint16_t)(ui16_motor_bemf_voltage_x1000 / (10U + SMOOTH_START_BEMF_REDUCE_FACTOR));
+		smooth_start_voltage_target_x100 += (uint32_t)(uint16_t)(ui16_motor_bemf_voltage_x1000 / (10U + SMOOTH_START_BEMF_REDUCE_FACTOR));//due to resolution of the pwm duty cycle, BEMF starts to increase the duty only above about 3erps
 		if (smooth_start_voltage_target_x100 > UINT16_MAX){
 			smooth_start_voltage_target_x100 = UINT16_MAX;
 		}
diff --git a/src/controller/main.h b/src/controller/main.h
index e2593c2a..2ef8d2db 100644
--- a/src/controller/main.h
+++ b/src/controller/main.h
@@ -16,9 +16,11 @@
 
 // PWM related values
 // motor
-#define PWM_CYCLES_SECOND                                       19047U // 52us (PWM period)
-#define PWM_CYCLES_COUNTER_MAX                                  3800U  // 5 erps minimum speed -> 1/5 = 200 ms; 200 ms / 50 us = 4000 (3125 at 15.625KHz)
-#define DOUBLE_PWM_CYCLES_SECOND                                38094 // 25us (2 irq x PWM period)
+#define PWM_PERIOD                                              420U
+#define PWM_DOUBLE_PERIOD                                       (2U*PWM_PERIOD) //PWM center aligned mode: counts from 0 to PWM_PERIOD and then down from PWM_PERIOD to 0
+#define PWM_CYCLES_SECOND                                       ((uint16_t)(HSE_VALUE / PWM_DOUBLE_PERIOD)) // 19047Hz - 52us (PWM period)  - !! has to be less than 21845
+#define DOUBLE_PWM_CYCLES_SECOND                                ((uint16_t)(HSE_VALUE / PWM_PERIOD))  // 25us (2 irq x PWM period)
+#define PWM_CYCLES_COUNTER_MAX                                  (DOUBLE_PWM_CYCLES_SECOND + 1U)  // +1U ensures ui16_motor_speed_erps is 0 when counter is max
 // ramp up/down PWM cycles count
 #define PWM_DUTY_CYCLE_RAMP_UP_INVERSE_STEP_CADENCE_OFFSET      60     // PWM_DUTY_CYCLE_RAMP_UP_INVERSE_STEP offset for cadence assist mode
 //#define PWM_DUTY_CYCLE_RAMP_UP_INVERSE_STEP_DEFAULT             195    // 160 -> 160 * 64 us for every duty cycle increment at 15.625KHz
diff --git a/src/controller/motor.c b/src/controller/motor.c
index b05e28b7..b66cb066 100755
--- a/src/controller/motor.c
+++ b/src/controller/motor.c
@@ -294,7 +294,7 @@ uint16_t ui16_PWM_cycles_counter_a = 3;
 uint8_t ui8_pwm_counter_valid_b = 0;
 uint16_t ui16_PWM_cycles_counter_b = 3;
 uint16_t ui16_PWM_cycles_counter_6 = 3;
-uint16_t ui16_PWM_cycles_counter_total = 0xffff;
+uint16_t ui16_PWM_cycles_counter_total = PWM_CYCLES_COUNTER_MAX;
 uint8_t ui8_motor_commutation_type = BLOCK_COMMUTATION;
 volatile uint16_t ui16_motor_speed_erps = 0;
 static uint8_t ui8_motor_rotor_absolute_angle;
@@ -539,7 +539,7 @@ void TIM1_CAP_COM_IRQHandler(void) __interrupt(TIM1_CAP_COM_IRQHANDLER)
         ui16_PWM_cycles_counter_6 = 2;
         ui8_pwm_counter_valid_a = 0;
         ui8_pwm_counter_valid_b = 0;
-        ui16_PWM_cycles_counter_total = 0xffff;
+        ui16_PWM_cycles_counter_total = PWM_CYCLES_COUNTER_MAX;
         ui8_g_foc_angle = 0;
         ui8_motor_commutation_type = BLOCK_COMMUTATION;
         ui8_hall_sensors_state_last = 0; // this way we force execution of hall sensors code next time
diff --git a/src/controller/pwm.c b/src/controller/pwm.c
index 8b38e965..58c58fbc 100644
--- a/src/controller/pwm.c
+++ b/src/controller/pwm.c
@@ -39,7 +39,7 @@ void pwm_init_bipolar_4q(void) {
     TIM1_TimeBaseInit(0, // TIM1_Prescaler = 0
             TIM1_COUNTERMODE_CENTERALIGNED3,
             // clock = 16MHz; counter period = 840; PWM freq = 16MHz / 840 = 19,047kHz;
-            420, // PWM center aligned mode: counts from 0 to 420 and then down from 420 to 0
+            PWM_PERIOD, // PWM center aligned mode: counts from 0 to PWM_PERIOD and then down from PWM_PERIOD to 0
             1);// will fire the TIM1_IT_UPDATE at every PWM period cycle
 
 //#define DISABLE_PWM_CHANNELS_1_3