diff --git a/inc/ultrasonic_driver.h b/inc/ultrasonic_driver.h
index 6307fba..3708871 100644
--- a/inc/ultrasonic_driver.h
+++ b/inc/ultrasonic_driver.h
@@ -35,10 +35,10 @@ void led_config(void);
 void usart_config(void);
 void ultrasonic_config(void);
 void ultrasonic_transmit_config(void);
-void ultrasonic_pwm_out_cycles(uint8_t cycles);
+void ultrasonic_pwm_out_cycles(const uint8_t cycles);
 
 
-void ultrasonic_transmit_delay(void);
+void ultrasonic_transmit_delay(const uint16_t micro_second);
 void recevice_exti_config(void);
 void ultrasonic_echo_timer_config(void);
 
diff --git a/src/ultrasonic_driver.c b/src/ultrasonic_driver.c
index 8402fce..5e4fb79 100644
--- a/src/ultrasonic_driver.c
+++ b/src/ultrasonic_driver.c
@@ -98,7 +98,7 @@ void ultrasonic_transmit_config(void) {
     ultrasonic_config();
 }
 
-void ultrasonic_pwm_out_cycles(uint8_t cycles) {
+void ultrasonic_pwm_out_cycles(const uint8_t cycles) {
     uint8_t current_cycle = 0;
 
     timer_channel_output_pulse_value_config(US_TRAN_TIMER, US_TRAN_CH, 120);
@@ -121,7 +121,7 @@ void ultrasonic_pwm_out_cycles(uint8_t cycles) {
     // }
 }
 
-void ultrasonic_transmit_delay(void) {
+void ultrasonic_transmit_delay(const uint16_t micro_second) {
     rcu_periph_clock_enable(RCU_GPIOA);
 
     /*
@@ -140,7 +140,7 @@ void ultrasonic_transmit_delay(void) {
     timer_initpara.prescaler         =71;
     timer_initpara.alignedmode       =TIMER_COUNTER_EDGE;
     timer_initpara.counterdirection  =TIMER_COUNTER_UP;
-    timer_initpara.period            =230 - 1;
+    timer_initpara.period            =micro_second - 1;
     timer_initpara.clockdivision     =TIMER_CKDIV_DIV1;
     timer_initpara.repetitioncounter =0;
     timer_init(TIMER15, &timer_initpara);