diff --git a/firmware/lib/bughal.c b/firmware/lib/bughal.c
index a959499..a25501e 100644
--- a/firmware/lib/bughal.c
+++ b/firmware/lib/bughal.c
@@ -65,10 +65,10 @@ void init_mic(void){
 	PORTB &= ~(1 << PORTB2);//and to GND	
 	ADMUX = (1<<REFS1) | (1<<REFS0); //use internal 1.1V as reference
   	ADCSRA = (1<<ADPS1) | (1<<ADPS0);// prescaler F_CPU/8
-        ADCSRA |= (1<<ADEN);             // ADC enable - turn it on
-        // do one conversion
-        ADCSRA |= (1<<ADSC);  
-  	while (ADCSRA & (1<<ADSC) ) {} //wait for conversion to end
+        ADCSRA |= (1<<ADEN) | (1<<ADATE);// ADC enable - turn it on in free running mode
+        ADCSRB &= (1<<ACME); //leave only ACME as it is (others zerp for free running)
+  	ADMUX = (ADMUX & ~(0x1F)) | 5; // select channel 5
+  	ADCSRA |= (1<<ADSC);            // start conversion
 	uint16_t dummy = ADCW; //read once 
 	return;
 }
diff --git a/firmware/main.c b/firmware/main.c
index 7677eaf..902a1a9 100644
--- a/firmware/main.c
+++ b/firmware/main.c
@@ -71,7 +71,6 @@ void do_mode0(void){
   // single measurement
   ADMUX = (ADMUX & ~(0x1F)) | 5; // select channel 5
   ADCSRA |= (1<<ADSC);            // start single conversion
-  while (ADCSRA & (1<<ADSC) ) {}; // wait for conversion to end
   curval =ADCW;                   // read result
   maxval = (curval>maxval) ? curval : maxval;