diff --git a/lib/si5351/si5351.c b/lib/si5351/si5351.c
--- a/lib/si5351/si5351.c
+++ b/lib/si5351/si5351.c
@@ -25,6 +25,8 @@
 #include <stdint.h>
 #include "stm32f0xx_hal.h"
 #include "si5351.h"
+#include "gpio.h"
+
 
 // Private prototypes
 uint64_t si5351_pll_calc(uint64_t, struct Si5351RegSet *, int32_t);
@@ -909,7 +911,11 @@ void si5351_set_clock_fanout(enum si5351
 
 uint8_t si5351_write_bulk(uint8_t addr, uint8_t bytes, uint8_t *data)
 {
-    HAL_I2C_Mem_Write(si5351_i2cport, SI5351_BUS_BASE_ADDR, addr, 1, data, bytes, 100);
+    HAL_Delay(300);
+    uint32_t res = HAL_I2C_Mem_Write(si5351_i2cport, SI5351_BUS_BASE_ADDR, addr, 1, data, bytes, 100);
+    led_blink(res);
+    HAL_Delay(300);
+
 
 
 /*
@@ -925,9 +931,12 @@ uint8_t si5351_write_bulk(uint8_t addr, 
 
 uint8_t si5351_write(uint8_t addr, uint8_t data)
 {
+    HAL_Delay(300);
     uint8_t data_arr[1] = {data};
-    HAL_I2C_Mem_Write(si5351_i2cport, SI5351_BUS_BASE_ADDR, addr, 1, data, 1, 100);
+    uint8_t res = HAL_I2C_Mem_Write(si5351_i2cport, SI5351_BUS_BASE_ADDR, addr, 1, data, 1, 100);
 
+    led_blink(res);
+    HAL_Delay(300);
 /*
 	Wire.beginTransmission(SI5351_BUS_BASE_ADDR);
 	Wire.write(addr);
@@ -940,8 +949,11 @@ uint8_t si5351_read(uint8_t addr)
 {
 	uint8_t data_arr[1] = {0};
 
-    HAL_I2C_Mem_Read(si5351_i2cport, SI5351_BUS_BASE_ADDR, addr, 1, data_arr, 1, 100);
+    HAL_Delay(300);
+    uint8_t res = HAL_I2C_Mem_Read(si5351_i2cport, SI5351_BUS_BASE_ADDR, addr, 1, data_arr, 1, 100);
 
+    led_blink(res);
+    HAL_Delay(300);
 /*
 	Wire.beginTransmission(SI5351_BUS_BASE_ADDR);
 	Wire.write(addr);