diff --git a/software/libcariboulite/src/caribou_smi/caribou_smi.c b/software/libcariboulite/src/caribou_smi/caribou_smi.c
index 1366d27..5d5a974 100644
--- a/software/libcariboulite/src/caribou_smi/caribou_smi.c
+++ b/software/libcariboulite/src/caribou_smi/caribou_smi.c
@@ -551,6 +551,7 @@ int caribou_smi_init(caribou_smi_st* dev,
     memset(&dev->debug_data, 0, sizeof(caribou_smi_debug_data_st));
 
     dev->debug_mode = caribou_smi_none;
+    dev->invert_iq = false;
     dev->initialized = 1;
 
     return 0;
@@ -573,6 +574,12 @@ void caribou_smi_set_debug_mode(caribou_smi_st* dev, caribou_smi_debug_mode_en m
     dev->debug_mode = mode;
 }
 
+//=========================================================================
+void caribou_smi_invert_iq(caribou_smi_st* dev, bool invert)
+{
+    dev->invert_iq = invert;
+}
+
 //=========================================================================
 int caribou_smi_read(caribou_smi_st* dev, caribou_smi_channel_en channel,
                     caribou_smi_sample_complex_int16* samples,
diff --git a/software/libcariboulite/src/caribou_smi/caribou_smi.h b/software/libcariboulite/src/caribou_smi/caribou_smi.h
index 7cb5627..37b6294 100644
--- a/software/libcariboulite/src/caribou_smi/caribou_smi.h
+++ b/software/libcariboulite/src/caribou_smi/caribou_smi.h
@@ -67,6 +67,8 @@ typedef struct
     
     uint8_t *read_temp_buffer;
     uint8_t *write_temp_buffer;
+    
+    bool invert_iq;
 
 	// debugging
 	caribou_smi_debug_mode_en debug_mode;
@@ -78,6 +80,8 @@ int caribou_smi_init(caribou_smi_st* dev,
 int caribou_smi_close (caribou_smi_st* dev);
 int caribou_smi_check_modules(bool reload);
 
+void caribou_smi_invert_iq(caribou_smi_st* dev, bool invert);
+
 void caribou_smi_set_debug_mode(caribou_smi_st* dev, caribou_smi_debug_mode_en mode);
 int caribou_smi_set_driver_streaming_state(caribou_smi_st* dev, smi_stream_state_en state);
 smi_stream_state_en caribou_smi_get_driver_streaming_state(caribou_smi_st* dev);
diff --git a/software/libcariboulite/src/cariboulite_radio.c b/software/libcariboulite/src/cariboulite_radio.c
index 4a40f44..6cdf8fb 100644
--- a/software/libcariboulite/src/cariboulite_radio.c
+++ b/software/libcariboulite/src/cariboulite_radio.c
@@ -72,11 +72,13 @@ int cariboulite_radio_ext_ref ( sys_st *sys, cariboulite_ext_ref_freq_en ref)
             ZF_LOGD("Setting ext_ref = 26MHz");
             at86rf215_set_clock_output(&sys->modem, at86rf215_drive_current_8ma, at86rf215_clock_out_freq_26mhz);
             rffc507x_setup_reference_freq(&sys->mixer, 26e6);
+            rffc507x_calibrate(&sys->mixer);
             break;
         case cariboulite_ext_ref_32mhz:
             ZF_LOGD("Setting ext_ref = 32MHz");
             at86rf215_set_clock_output(&sys->modem, at86rf215_drive_current_8ma, at86rf215_clock_out_freq_32mhz);
             rffc507x_setup_reference_freq(&sys->mixer, 32e6);
+            rffc507x_calibrate(&sys->mixer);
             break;
         case cariboulite_ext_ref_off:
             ZF_LOGD("Setting ext_ref = OFF");
@@ -678,12 +680,13 @@ int cariboulite_radio_set_frequency(cariboulite_radio_state_st* radio,
 																at86rf215_rf_channel_2400mhz, 
 																modem_freq);
             
-            // setup mixer LO according to the actual modem frequency
-			lo_act_freq = rffc507x_set_frequency(&radio->sys->mixer, modem_act_freq + f_rf);
-			act_freq = lo_act_freq - modem_act_freq;
+            // setup mixer LO according to the actual modem frequency          
+			lo_act_freq = rffc507x_set_frequency(&radio->sys->mixer, modem_act_freq - f_rf);
+			act_freq = modem_act_freq - lo_act_freq;
 
             // setup fpga RFFE <= upconvert (tx / rx)
             conversion_direction = conversion_dir_up;
+            caribou_smi_invert_iq(&radio->sys->smi, true);
         }
         //-------------------------------------
         else if ( f_rf >= CARIBOULITE_2G4_MIN && 
@@ -698,6 +701,7 @@ int cariboulite_radio_set_frequency(cariboulite_radio_state_st* radio,
             lo_act_freq = 0;
             act_freq = modem_act_freq;
             conversion_direction = conversion_dir_none;
+            caribou_smi_invert_iq(&radio->sys->smi, true);
         }
         //-------------------------------------
         else if ( f_rf >= (CARIBOULITE_2G4_MAX) && 
@@ -715,6 +719,7 @@ int cariboulite_radio_set_frequency(cariboulite_radio_state_st* radio,
 
             // setup fpga RFFE <= downconvert (tx / rx)
             conversion_direction = conversion_dir_down;
+            caribou_smi_invert_iq(&radio->sys->smi, true);
         }
         //-------------------------------------
         else
diff --git a/software/libcariboulite/src/rffc507x/rffc507x.c b/software/libcariboulite/src/rffc507x/rffc507x.c
index edef6cb..0554c3a 100644
--- a/software/libcariboulite/src/rffc507x/rffc507x.c
+++ b/software/libcariboulite/src/rffc507x/rffc507x.c
@@ -148,14 +148,13 @@ int rffc507x_init(  rffc507x_st* dev,
 	set_RFFC507X_MODE(dev, 1);
 
 	// put zeros in freq contol registers
-	//set_RFFC507X_P2VCOSEL(dev, 0);
-	//set_RFFC507X_CTMAX(dev, 127);
-	//set_RFFC507X_CTMIN(dev, 0);
-	//set_RFFC507X_P2CTV(dev, 12);	
-	//set_RFFC507X_P1CTV(dev, 12);
-	set_RFFC507X_RGBYP(dev, 1);
-	//set_RFFC507X_P2MIXIDD(dev, 4);
-	//set_RFFC507X_P1MIXIDD(dev, 4);
+	set_RFFC507X_P2VCOSEL(dev, 0);
+	set_RFFC507X_CTMIN(dev, 0);
+    set_RFFC507X_CTMAX(dev, 127);
+    set_RFFC507X_P2CTV(dev, 12);
+    set_RFFC507X_RGBYP(dev, 1);
+    set_RFFC507X_FULLD(dev, 0);
+	set_RFFC507X_P2MIXIDD(dev, 4);
 	
 	// Others
 	set_RFFC507X_LDEN(dev, 1);
@@ -333,7 +332,8 @@ double rffc507x_set_frequency(rffc507x_st* dev, double lo_hz)
 	set_RFFC507X_P2LODIV(dev, n_lo);
 	set_RFFC507X_P2N(dev, n);
 	set_RFFC507X_P2PRESC(dev, fbkdiv >> 1);
-	set_RFFC507X_P2VCOSEL(dev, 2);
+	//set_RFFC507X_P2VCOSEL(dev, 0);
+    set_RFFC507X_AUTO(dev, 1);
 	set_RFFC507X_P2NMSB(dev, p1nmsb);
 	set_RFFC507X_P2NLSB(dev, p1nlsb);