diff --git a/inc/utils.h b/inc/utils.h
index 621af0c2..05ab50fe 100644
--- a/inc/utils.h
+++ b/inc/utils.h
@@ -1,8 +1,8 @@
-// Different utilities
+// General purpose function/macros
 
 #ifndef __UTILS_H__
 #define __UTILS_H__
 
-int utils_get_uart_key();
+#define ABSDIFF( x, y ) ( ( x ) >= ( y ) ? ( x ) - ( y ) : ( y ) - ( x ) )
 
 #endif
diff --git a/src/platform/at91sam7x/platform.c b/src/platform/at91sam7x/platform.c
index d64a9d51..c4f37fd8 100644
--- a/src/platform/at91sam7x/platform.c
+++ b/src/platform/at91sam7x/platform.c
@@ -16,8 +16,7 @@
 #include <string.h>
 #include <ctype.h>
 #include <stdio.h>
-
-#define PABS( x ) ( ( x ) >= 0 ? ( x ) : -( x ) )
+#include "utils.h"
 
 // *****************************************************************************
 // std functions
@@ -287,7 +286,7 @@ static u32 platform_timer_set_clock( unsigned id, u32 clock )
   unsigned i, mini = 0;
   
   for( i = 0; i < 5; i ++ )
-    if( PABS( clock - BOARD_MCK / clkdivs[ i ] ) < PABS( clock - BOARD_MCK / clkdivs[ mini ] ) )
+    if( ABSDIFF( clock, BOARD_MCK / clkdivs[ i ] ) < ABSDIFF( clock, BOARD_MCK / clkdivs[ mini ] ) )
       mini = i;
   TC_Configure( ( AT91S_TC* )timer_base[ id ], mini | AT91C_TC_WAVE );  
   return BOARD_MCK / clkdivs[ mini ];
diff --git a/src/platform/lm3s/platform.c b/src/platform/lm3s/platform.c
index acdfaa6a..1470a9f8 100644
--- a/src/platform/lm3s/platform.c
+++ b/src/platform/lm3s/platform.c
@@ -23,6 +23,7 @@
 #include "ssi.h"
 #include "timer.h"
 #include "pwm.h"
+#include "utils.h"
 
 // *****************************************************************************
 // std function
@@ -439,7 +440,6 @@ u32 platform_timer_get_diff_us( unsigned id, timer_data_type end, timer_data_typ
 // PWMs
 
 #define PLATFORM_NUM_PWMS               6
-#define PABS( x )                       ( ( x ) < 0 ? -( x ) : ( x ) )
 
 // SYSCTL div data and actual div factors
 const static u32 pwm_div_ctl[] = { SYSCTL_PWMDIV_1, SYSCTL_PWMDIV_2, SYSCTL_PWMDIV_4, SYSCTL_PWMDIV_8, SYSCTL_PWMDIV_16, SYSCTL_PWMDIV_32, SYSCTL_PWMDIV_64 };
@@ -479,7 +479,7 @@ static u32 platform_pwm_set_clock( u32 clock )
   
   sysclk = SysCtlClockGet();
   for( i = min_i = 0; i < sizeof( pwm_div_data ) / sizeof( u8 ); i ++ )
-    if( PABS( clock - sysclk / pwm_div_data[ i ] ) < PABS( clock - sysclk / pwm_div_data[ min_i ] ) )
+    if( ABSDIFF( clock, sysclk / pwm_div_data[ i ] ) < ABSDIFF( clock, sysclk / pwm_div_data[ min_i ] ) )
       min_i = i;
   SysCtlPWMClockSet( pwm_div_ctl[ min_i ] );
   return sysclk / pwm_div_data[ min_i ];
diff --git a/src/platform/lpc288x/platform.c b/src/platform/lpc288x/platform.c
index 5e702936..91c22133 100644
--- a/src/platform/lpc288x/platform.c
+++ b/src/platform/lpc288x/platform.c
@@ -13,6 +13,7 @@
 #include "lpc288x.h"
 #include "target.h"
 #include "uart.h"
+#include "utils.h"
 
 // *****************************************************************************
 // std functions
@@ -189,7 +190,6 @@ static const vu_ptr tmr_value[] = { &T0VALUE, &T1VALUE };
 static const vu_ptr tmr_ctrl[] = { &T0CTRL, &T1CTRL };
 static const vu_ptr tmr_clr[] = { &T0CLR, &T1CLR };
 static const unsigned tmr_prescale[] = { 1, 16, 256, 1 };
-#define TABS( x ) ( ( x ) < 0 ? -( x ) : ( x ) )
 
 // Helper: get timer clock
 static u32 platform_timer_get_clock( unsigned id )
@@ -203,7 +203,7 @@ static u32 platform_timer_set_clock( unsigned id, u32 clock )
   unsigned i, mini = 0;
   
   for( i = 0; i < 3; i ++ )
-    if( TABS( clock - MAIN_CLOCK / tmr_prescale[ i ] ) < TABS( clock - MAIN_CLOCK / tmr_prescale[ mini ] ) )
+    if( ABSDIFF( clock, MAIN_CLOCK / tmr_prescale[ i ] ) < ABSDIFF( clock, MAIN_CLOCK / tmr_prescale[ mini ] ) )
       mini = i;
   *tmr_ctrl[ id ] = ( *tmr_ctrl[ id ] & ~0xB ) | ( mini << 2 );
   return MAIN_CLOCK / tmr_prescale[ mini ];
diff --git a/src/platform/lpc288x/uart.c b/src/platform/lpc288x/uart.c
index fc462204..de71858a 100644
--- a/src/platform/lpc288x/uart.c
+++ b/src/platform/lpc288x/uart.c
@@ -7,8 +7,7 @@
 #include <reent.h>
 #include <errno.h>
 #include <string.h>
-
-#define LABS( x ) ( ( x ) < 0 ? -( x ) : ( x ) )
+#include "utils.h"
 
 // Structure with UART baud/parameters 
 // Computed used Philip's "baud rate calculator" XLS file
@@ -68,7 +67,7 @@ u32 uart_init( u32 baud, int databits, int parity, int stopbits )
   
   // Find correct baud
   for( i = minpos = 0; i < sizeof( uart_baudinfo ) / sizeof( UART_BAUDDATA ); i ++ )
-    if( LABS( baud - uart_baudinfo[ i ].baud ) < LABS( baud - uart_baudinfo[ minpos ].baud ) )
+    if( ABSDIFF( baud, uart_baudinfo[ i ].baud ) < ABSDIFF( baud, uart_baudinfo[ minpos ].baud ) )
       minpos = i;
   pdata = uart_baudinfo + minpos;