diff --git a/datasheets/OP37GS.pdf b/datasheets/OP37GS.pdf
new file mode 100644
index 0000000..7bfa244
Binary files /dev/null and b/datasheets/OP37GS.pdf differ
diff --git a/documentation/SPI-Proto b/documentation/SPI-Proto
index 56c3441..557e7f0 100644
--- a/documentation/SPI-Proto
+++ b/documentation/SPI-Proto
@@ -30,3 +30,8 @@ Where following values are Valid:
 |						Thermometer					Representing 	Temperature|
 |						Starting with 0					the Temperature		   |
 |--------------------------------------------------------------------------------------------------------------------------|
+
+
+Änderungen: 
+1 ist nun Echo.
+7 ist read-temp
diff --git a/firmware/shared/spi.c b/firmware/shared/spi.c
index 2077c82..3ad03cb 100644
--- a/firmware/shared/spi.c
+++ b/firmware/shared/spi.c
@@ -83,16 +83,17 @@ void spi_init(){
 
 void spi_mst_start_packet(){
 #ifdef SPI_MASTER
+	_delay_us(2*1e6/SPI_BAUDRATE);
 	SPI_SSOUT &= ~(_BV(SPI_SS_PIN));
-	_delay_us(1e6/SPI_BAUDRATE);
+	_delay_us(2*1e6/SPI_BAUDRATE);
 #endif
 }
 
 void spi_mst_end_packet(){
 #ifdef SPI_MASTER
-	_delay_us(1e6/SPI_BAUDRATE);
+	_delay_us(2*1e6/SPI_BAUDRATE);
 	SPI_SSOUT |= _BV(SPI_SS_PIN);
-	_delay_us(1e6/SPI_BAUDRATE);
+	_delay_us(2*1e6/SPI_BAUDRATE);
 #endif
 }
 
@@ -124,6 +125,11 @@ void spi_mst_write_read(uint8_t len, uint8_t *data){
 	}
 }
 
+void spi_mst_packet_delay(){
+    // wait for 2 byte
+    _delay_us(16*1e6/SPI_BAUDRATE);
+}
+
 #ifndef SPI_MASTER
 
 void spi_sla_handle_packet(){
diff --git a/firmware/shared/spi_proto.c b/firmware/shared/spi_proto.c
index e55fc05..a354276 100644
--- a/firmware/shared/spi_proto.c
+++ b/firmware/shared/spi_proto.c
@@ -20,6 +20,7 @@ uint16_t spi_master_transceive(uint8_t opcode, uint8_t addr, uint16_t value)
 		spi_mst_start_packet();
 		spi_mst_write_read(5,mst_buf);
 		spi_mst_end_packet();
+        spi_mst_packet_delay();
 		for(uint8_t i=0; i<5; ++i){
 			mst_buf[0] = 0;
 			mst_buf[1] = 0;
@@ -33,6 +34,7 @@ uint16_t spi_master_transceive(uint8_t opcode, uint8_t addr, uint16_t value)
 			if(mst_buf[1] == opcode && mst_buf[2] == addr){ // valid answer
 				return ((mst_buf[3] << 8) | mst_buf[4]);
 			}
+            spi_mst_packet_delay();
 		}
 //	}
 	return 0xffff; // error-code
@@ -90,7 +92,7 @@ uint16_t spi_proto_slaveaction(uint8_t opcode, uint8_t addr, uint16_t data) {
 			(*spi_proto_globals16[addr]) = data;
 			break;
 		case 6:
-			(*spi_proto_funcs[addr])();
+			retval = (*spi_proto_funcs[addr])(data);
 			//TODO: prevent a function from being run several times because the message gets repeated.
 			break;
 		case 7:
diff --git a/firmware/slavechip/filter.c b/firmware/slavechip/filter.c
index 0ea3379..0e8355e 100644
--- a/firmware/slavechip/filter.c
+++ b/firmware/slavechip/filter.c
@@ -1,6 +1,7 @@
 
 #include "filter.h"
 #include <math.h>
+#include "debug.h"
 
 Sensordata sensordata[4];
 float ambient_temp=25.;
@@ -13,7 +14,7 @@ float avg_noise[CHANNELCOUNT];
 
 
 void process_thermocouple_value(int16_t raw_data, uint8_t channel){
-    dbgLog("procthermval, val %i, chan %i",raw_data,channel);
+//    dbgLog("procthermval, val %i, chan %i",raw_data,channel);
     // This function does everything that needs to be done to raw adc values
     float a = raw_data;
     a -= sensordata[channel].offset; 
@@ -37,7 +38,7 @@ void process_ambient_value(int16_t raw_data){
     a = a * 0.03125; //adc to mV after amp
     a = a / 9.625;
     ambient_temp = a;
-    dbgLog("ambient: %3.3f°C (lastval %i)\n",a, raw_data);
+    dbgLog("ambient: %3.3f°C (value %i)\n",a, raw_data);
 }
 
 
diff --git a/firmware/slavechip/main.c b/firmware/slavechip/main.c
index 9bb9bf3..d43025d 100644
--- a/firmware/slavechip/main.c
+++ b/firmware/slavechip/main.c
@@ -56,11 +56,12 @@ int __attribute__((noreturn)) main(void) {
 
 	int16_t data;
 	for(;;){
+        _delay_ms(4000);
         dbgLog("loop iteration\n");
 
 		// measure temps 5*2 times
 		for(uint8_t i=0; i<5; i++) {
-            dbgLog("starting temp measuring");
+//            dbgLog("starting temp measuring\n");
 			for(uint8_t active_sensor=0; active_sensor<2; active_sensor++) { // only measuring two probes atm
 				muxer_set(active_sensor);
 				while(!mcpadc_has_new_data()) _delay_ms(10);
@@ -69,14 +70,15 @@ int __attribute__((noreturn)) main(void) {
 				
 				data = mcpadc_get_data();
                 process_thermocouple_value(data,active_sensor);
+                _delay_ms(1000);
 			}
             dbgLog("a");
 		}
 
-		dbgLog("now measuring offsets");
+//		dbgLog("now measuring offsets\n");
 		// measure 2 offsets
 		for(uint8_t active_sensor=0; active_sensor<2; active_sensor++) { // only measuring two offsets atm
-			dbgLog("active sensor: %i",active_sensor);
+//			dbgLog("active sensor: %i",active_sensor);
 			muxer_set(active_sensor);
 			offset_measure_start(active_sensor);
 			while(!mcpadc_has_new_data()) _delay_ms(10);
@@ -84,7 +86,7 @@ int __attribute__((noreturn)) main(void) {
 			while(!mcpadc_has_new_data()) _delay_ms(10);
 
 			data = mcpadc_get_data();
-			dbgLog("retrieved offset data %i", data);
+//			dbgLog("retrieved offset data %i\n", data);
 			// TODO: what to do with the offset?
 			
 			offset_measure_stop();
diff --git a/firmware/slavechip/spi_pointers.h b/firmware/slavechip/spi_pointers.h
index 575b961..b8e1f88 100644
--- a/firmware/slavechip/spi_pointers.h
+++ b/firmware/slavechip/spi_pointers.h
@@ -3,7 +3,7 @@
 
 #include <stdint.h>
 
-typedef void(*funptr_t)();
+typedef int16_t(*funptr_t)(int16_t);
 
 extern uint8_t *spi_proto_globals8[];
 extern uint16_t *spi_proto_globals16[];