diff --git a/src/commands.c b/src/commands.c
index 5448225..7dd2253 100644
--- a/src/commands.c
+++ b/src/commands.c
@@ -25,8 +25,6 @@ void cmd_collect_char(char c)
 		
 
 	if (c == 0xD) {
-		printf("\n\r");
-
 		/* Null-terminate the string */
 		command.buf[command.index-1] = '\0';
 		cmd_handle(&command);
@@ -48,15 +46,41 @@ void cmd_handle(cmd_t *command)
 
 void cmd_handle_set(char *op1, char *op2) 
 {
-	int val;
+	long int val;
+	char *end;
 
 	if (0 == strcmp(op1, "t0_top")) {
-		val = atoi(op2);
-		if (val) {
+		val = strtol(op2, &end, 10);
+		if (op2 != end) {
 			OCR0A = val;
-			printf("Setting Timer0 TOP to %i\r\n", val);
+			printf("Setting Timer0 TOP to %li\r\n", val);
 		}
 		 else
 		 	printf("No valid value for t0_top given\n\r");
 	}
+	else if (0 == strcmp(op1, "t0_ps")) {
+		val = strtol(op2, &end, 10);
+		TCCR0B &= ~((1 << CS00) | (1 << CS01) | (1 << CS02));
+		switch (val)
+		{
+		case 0:
+			TCCR0B |= (1 << CS00);
+			break;
+		case 8:
+			TCCR0B |= (1 << CS01);
+			break;
+		case 64:
+			TCCR0B |= (1 << CS00) | (1 << CS01);
+			break;
+		case 256:
+			TCCR0B |= (1 << CS02);
+			break;
+		case 1024:
+			TCCR0B |= (1 << CS02) | (1 << CS00);
+			break;
+		default:
+			printf("No valid prescaler value.\n\r");
+			break;
+		}
+	}
 }
\ No newline at end of file
diff --git a/src/inverter.c b/src/inverter.c
index 0be082c..aa6e7f7 100644
--- a/src/inverter.c
+++ b/src/inverter.c
@@ -20,7 +20,7 @@ int main()
 
 	while (1) {
 		if ((PORTB & (1<<PB2))>1)  {
-			_delay_us(10);
+			_delay_us(1);
 			PORTB &= ~(1<<PB2);
 		}	
 	}
@@ -33,10 +33,3 @@ ISR(TIMER0_COMPA_vect)
 	PORTB |= (1 << PB2);
 }
 
-ISR(USART1_RX_vect)
-{
-	char u;
-	u = UDR1;
-	
-	cmd_collect_char(u);
-}
diff --git a/src/timer.c b/src/timer.c
index 613200b..141627d 100644
--- a/src/timer.c
+++ b/src/timer.c
@@ -9,8 +9,8 @@ void initCtcTimer0(void)
 	/* Enable Counter0 Compare Match A Interrupt */
 	TIMSK0 |= (1 << OCIE0A);
 	
-	/* Select clock. Prescaler of 1024 */
-	TCCR0B |= (1 << CS02) | (1 << CS00);
+	/* Select clock. Prescaler of 8 */
+	TCCR0B |= (1 << CS01);
 	
 	/* Use CTC Mode */
 	TCCR0A |= (1 << WGM01);
@@ -18,7 +18,7 @@ void initCtcTimer0(void)
 	/* 
 	 * OCR0A contains TOP value for counter:
 	 */
-	OCR0A = 78;
+	OCR0A = 25;
 }
 
 void initOverflowTimer0(void)
@@ -34,4 +34,4 @@ void initOverflowTimer1(void)
 {
 	TCCR1B |= (1<<CS11);
 	TIMSK1 |= (1<<TOIE1);
-}
+}
\ No newline at end of file
diff --git a/src/uart.c b/src/uart.c
index 91c89c5..970ffbf 100644
--- a/src/uart.c
+++ b/src/uart.c
@@ -1,6 +1,8 @@
 #include <avr/io.h>
+#include <avr/interrupt.h>
 
 #include "include/uart.h"
+#include "include/commands.h"
 
 static FILE stream = FDEV_SETUP_STREAM(uart_printf, NULL, _FDEV_SETUP_WRITE);
 
@@ -40,3 +42,10 @@ int uart_printf(char var, FILE *stream)
 	return 0;
 }
 
+ISR(USART1_RX_vect)
+{
+	char u;
+	u = UDR1;
+	
+	cmd_collect_char(u);
+}
\ No newline at end of file