diff --git a/firmware/main.c b/firmware/main.c
index f6e1301..5a3a3c5 100644
--- a/firmware/main.c
+++ b/firmware/main.c
@@ -3,6 +3,7 @@
 #include <avr/pgmspace.h>
 #include <avr/eeprom.h>
 #include <util/delay.h>
+#include <util/atomic.h>
 #include <stdio.h>
 
 #include <usbdrv/usbdrv.h>
@@ -14,6 +15,28 @@
 
 static uint8_t newThermoData = 1;
 static uint16_t thermoData[] = {1024, 814, 2475, 2243};
+volatile uint16_t timer1_acc;
+
+#define SOFTTIMERNUMS 4
+uint16_t softtimer_last[SOFTTIMERNUMS];
+
+void softtimer_reset(uint8_t timernum){
+    softtimer_last[SOFTTIMERNUMS] = timer1_acc;
+}
+
+uint8_t softtimer(uint8_t timernum, uint16_t interval){
+    uint16_t timer1_acc_tmp = timer1_acc;  // because of volatile
+    if((uint16_t)(timer1_acc_tmp - (uint16_t)(softtimer_last[timernum]) >= interval )){
+        softtimer_last[timernum] = timer1_acc_tmp;
+        return(1);
+    }
+    return(0);
+}
+
+#define SOFTTIMER(n,a) if(softtimer((n),(a*4)))
+
+
+
 
 
 void hardinit() {
@@ -100,7 +123,9 @@ int __attribute__((noreturn)) main(void) {
   for(;;){
     usbPoll();
 
-    updateDisplay();
+    SOFTTIMER(1,100){
+        updateDisplay();
+    }
 
     thermoData[0]=thermoData[0]+5;
     thermoData[1]=thermoData[1]+15;
@@ -108,8 +133,6 @@ int __attribute__((noreturn)) main(void) {
     thermoData[3]=thermoData[3]+18;
     i++; if(i%200 == 0) newThermoData = 1;
   }
-
-
 }
 
 /*
@@ -119,3 +142,16 @@ int __attribute__((noreturn)) main(void) {
   asm volatile ("out %1, %0\n" : "=r" (sreg_store) : "I" (_SFR_IO_ADDR(SREG)));
   reti();
   }*/
+ISR(TIMER1_OVF_vect,ISR_NOBLOCK){
+    uint16_t temp;
+    temp=timer1_acc;
+    temp++;
+    ATOMIC_BLOCK(ATOMIC_FORCEON){ 
+        timer1_acc=temp;
+    }
+    /* the ATOMIC is acutally only needed if timer1_acc is never read from an ISR, which
+     * is probably the case.
+     * ATOMIC_FORCEON: the ISR_NOBLOCK sets sei() a few cycles before.
+     */
+}
+
diff --git a/firmware/main.h b/firmware/main.h
index 2f91f00..a3f9254 100644
--- a/firmware/main.h
+++ b/firmware/main.h
@@ -1,15 +1,12 @@
 /* Anschlüsse sind:
- * B0 	 - 1wire               
+ * B0    - LCD (RS)
  * B1 	 - Kontrast-PWM
  * B2 	 - Backlight-PWM
- * B3-B5 - ISP
- * C0-C1 - 2farb-LED
- * C2 	 - LED
- * C3-C4 - Knopf-drehung
- * C5 	 - Knopf-taster
- * C6 	 - ISP
- * D0-6  - LCD (DB4-7, RS, R/W, EN)
- * D7 	 - LED
+ * B3-B5 - ISP/SPI
+ * C0-5  - LCD (DB4-7, R/W, EN)
+ * D2,D4 - USB
+ * D7    - SPI (SS master)
+ *
  */
 
 
@@ -30,63 +27,8 @@
 #define BACKLIGHTPIN 2
 
 
-// button handling
-#define BUTTPIN PINC
-#define BUTTLPIN 5
-#define BUTTRPIN 4
-#define BUTTTPIN 3
 
-#define BUTTEV_PUSH 1
-#define BUTT_BOUNCE 25 //approx ms debounce time
 
-extern uint8_t buttonevent;
-extern int8_t buttoninc; // how much the button turned.
-			// you might want to subtract turns you consumed since the variable 
-			// is updated in an interrupt
 
 
-//uint8_t volatile timer1_acc;
-
-#define FLOWTEMP_MAX 100
-#define FLOWTEMP_MIN 5
-#define FLOWTEMP_DEFAULT 70
-#define FLOWTEMP_ALARM_MIN 50
-#define FLOWTEMP_ALARM_MAX 100
-#define FLOWTEMP_ALARM_DEFAULT 87
-#define FLOWTEMP_RANGE_MAX 40
-#define FLOWTEMP_RANGE_DEFAULT 15
-extern uint8_t flowtemp_alarm;
-extern uint8_t flowtemp_range;
-extern uint8_t flowtemp;
-
-
-
-void set_display_brightness(uint8_t display_brightness);
-void store_display_brightness(uint8_t new_brightness);
-uint8_t load_display_brightness();
-
-void set_display_contrast(uint8_t display_contrast);
-void store_display_contrast(uint8_t new_contrast);
-uint8_t load_display_contrast();
-
-void set_flowtemp(uint8_t new_flowtemp);
-void store_flowtemp(uint8_t new_flowtemp);
-uint8_t load_flowtemp();
-
-void set_flowtemp_range(uint8_t new_flowtemp_range);
-void store_flowtemp_range(uint8_t new_flowtemp_range);
-uint8_t load_flowtemp_range();
-
-void set_flowtemp_alarm(uint8_t new_flowtemp_alarm);
-void store_flowtemp_alarm(uint8_t new_flowtemp_alarm);
-uint8_t load_flowtemp_alarm();
-
-
-// clock
-extern struct clockfmt {
-	uint8_t hour;
-	uint8_t minute;
-	uint8_t second;
-} clock;
-
 #endif //__MAIN_H