diff --git a/snippets/test1/test1.c b/snippets/test1/test1.c
index f89c022..5f3816b 100644
--- a/snippets/test1/test1.c
+++ b/snippets/test1/test1.c
@@ -3,7 +3,7 @@
 #include <stdint.h>
 #include <stdio.h>
 #include <unistd.h>
-
+#include <pthread.h>
 
 const int CTRL_OUT = 16;
 const int INTR_IN  = 19;
@@ -61,8 +61,10 @@ const uint8_t MDR1_F_CY  = 0b10000000;
 
 
 volatile uint32_t ec = 0;
-volatile uint32_t savedCounter = 0;
-uint32_t lastSavedCounter = 0;
+volatile uint32_t diff = 0;
+
+pthread_mutex_t eventMutex = PTHREAD_MUTEX_INITIALIZER;
+pthread_cond_t eventSignal = PTHREAD_COND_INITIALIZER;
 
 void writeCmd(uint8_t c) {
   uint8_t buf[1];
@@ -93,8 +95,18 @@ uint32_t read32(uint8_t c) {
 }
 
 void isr() {
-  savedCounter = read32(CMD_RD | REG_OTR);
+  static uint32_t lastCounter = 0;
+
+  uint32_t currentCounter = read32(CMD_RD | REG_OTR);
+
+  diff = currentCounter - lastCounter;
+  lastCounter = currentCounter;
+
   ec++;
+  
+  pthread_mutex_lock(&eventMutex);
+  pthread_cond_signal(&eventSignal);
+  pthread_mutex_unlock(&eventMutex);
 }
 
 void init() {
@@ -120,10 +132,10 @@ int main (void) {
   initCounter();
 
   while (1) {
-    uint32_t diff = savedCounter - lastSavedCounter;
-    lastSavedCounter = savedCounter;
-    printf("%d %d\n", ec, diff);
+    pthread_mutex_lock(&eventMutex);
+    pthread_cond_wait(&eventSignal, &eventMutex);
+    pthread_mutex_unlock(&eventMutex);
 
-    sleep(1);
+    printf("%d %d\n", ec, diff);
   }
 }