diff --git a/robot/include/sonar.h b/robot/include/sonar.h
index b8ad087..ef4227f 100644
--- a/robot/include/sonar.h
+++ b/robot/include/sonar.h
@@ -17,9 +17,9 @@
 
 #define SPEED_OF_SOUND      343 // 20°C dry air (m/s)
 #define MAX_SONAR_RANGE     8 // Trigger + echo (m)
-#define MIN_SONAR_RANGE     3 // Minimum distance that is still reliable
+#define MIN_SONAR_RANGE     4 // Minimum distance that is still reliable
 #define SONAR_DELAY	        60 // Timeout for return signal
-#define TIMER_MAX           65535 // For 16-bit timer
+#define TIMER_MAX           255 // For 8-bit timer
 #define CYCLES_PER_US       (F_CPU / 1000000)
 #define SONAR_TIMEOUT 	    (F_CPU * MAX_SONAR_RANGE) / SPEED_OF_SOUND
 
diff --git a/robot/src/sonar.c b/robot/src/sonar.c
index 8db9d31..26c58fa 100644
--- a/robot/src/sonar.c
+++ b/robot/src/sonar.c
@@ -1,7 +1,6 @@
 #include <avr/interrupt.h>
 #include <util/delay.h>
 #include "sonar.h"
-#include "led.h"
 
 volatile uint32_t trig_counter;
 volatile uint32_t no_of_ticks;
@@ -27,27 +26,27 @@ int32_t read_sonar(void)
         }
     }
 
-    TCNT1 = 0;
-    SET(TCCR1B, CS10); // Prescaler = 1
-    SET(TIMSK1, TOIE1); // Enable overflow interrupts
+    TCNT2 = 0;
+    SET(TCCR2B, CS20); // Prescaler = 1
+    SET(TIMSK2, TOIE2); // Enable overflow interrupts
     no_of_ticks = 0; // Reset overflow counter
 
     sei();
     // Count cycles until ECHO goes low
     while (CHK(ECHO_PIN, ECHO_BIT)) {
-        if (no_of_ticks + TCNT1 > SONAR_TIMEOUT) {
+        if (no_of_ticks + TCNT2 > SONAR_TIMEOUT) {
             return ECHO_TIMEOUT;
         }
     }
-    TCCR1B = 0x00;
+    TCCR2B = 0x00; // Stop TIMER2
     cli();
 
-    no_of_ticks += TCNT1;
+    no_of_ticks += TCNT2;
 
     return (uint16_t)(no_of_ticks / (CYCLES_PER_US * 58));
 }
 
-ISR(TIMER1_OVF_vect)
+ISR(TIMER2_OVF_vect)
 {
     no_of_ticks += TIMER_MAX;
 }