diff --git a/firmware/slavechip/filter.c b/firmware/slavechip/filter.c
index 37945ea..b4dd7a0 100644
--- a/firmware/slavechip/filter.c
+++ b/firmware/slavechip/filter.c
@@ -34,10 +34,11 @@ void process_offset_value(int16_t raw_data, uint8_t channel){
 }
 
 void process_ambient_value(int16_t raw_data){
-    // 9.625mV after amp  per °C
+    // old value: 9.625mV after amp  per °C
+    // new: 9.313 after amp  per °C
     float a = raw_data;
     a = a * 0.03125; //adc to mV after amp
-    a = a / 9.625;
+    a = a / 9.313;
     ambient_temp = a;
     printf("ambient: %3.3f°C (lastval %i)\n", a, raw_data);
 }
diff --git a/firmware/slavechip/main.c b/firmware/slavechip/main.c
index 0fd4dfb..75cd804 100644
--- a/firmware/slavechip/main.c
+++ b/firmware/slavechip/main.c
@@ -72,7 +72,6 @@ int __attribute__((noreturn)) main(void) {
 			for(uint8_t active_sensor=0; active_sensor<2; active_sensor++) { // only measuring two probes atm
                 printf("=== active sensor: %i\n",active_sensor);
 				muxer_set(active_sensor);
-                _delay_ms(1000);
 				while(!mcpadc_has_new_data()) _delay_ms(10);
 				mcpadc_get_data(); // first data after switch to trash
 				while(!mcpadc_has_new_data()) _delay_ms(10);
@@ -101,7 +100,7 @@ int __attribute__((noreturn)) main(void) {
         
         // measure ambient
         printf("====== now measuring ambient\n");
-        muxer_set(5);
+        muxer_set(4);
         while(!mcpadc_has_new_data()) _delay_ms(10);
         mcpadc_get_data(); // first data after switch to trash
         while(!mcpadc_has_new_data()) _delay_ms(10);
diff --git a/firmware/slavechip/muxer.c b/firmware/slavechip/muxer.c
index 8671753..f0669db 100644
--- a/firmware/slavechip/muxer.c
+++ b/firmware/slavechip/muxer.c
@@ -26,8 +26,8 @@ void muxer_set(uint8_t channel){
 
 
 uint8_t inline muxer_channel_to_selectbits(uint8_t channel){
-	static uint8_t table[] = {2,1,0,3};
-	if(channel>=4){
+	static uint8_t table[] = {2,1,0,3,5,7,6,4};
+	if(channel>=8){
 		return 0;
 	}
 	return(table[channel]);