diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1087767..5e5636d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,26 @@
 # Changelog
 
+## v1.5.1
+
+Mostly bugfixes with only minor new features
+
+- New features:
+  - Z0 of through standard now adjustable
+  - Option to automatically adjust the span to the active calibration
+- Bugfixes:
+  - Make De-embedding menu visible on MacOS
+  - Detection of handling of LibreCAL in the automatic calibration dialog
+  - Allow updates of devices with older firmwares (a matching older GUI version had to be used previously)
+  - Fix port excitation when not all S-parameters are measured
+  - Do not use DFT in spectrum analyzer when in zero span mode
+  - Readback of certain GUI values on Windows now correct (was stuck on 0 before)
+  - Prevent crash when disconnecting the device while a dialog was open
+  - Prevent occasional crash at the end of calibration measurements
+  - Fix spikes in sweep when a frequency calibration is set
+  - Improve sample timing between ADC and FPGA (resulted in very noisy traces on some devices)
+
 ## v1.5.0
+
 - New features:
   - Further abstraction from the LibreVNA hardware. The GUI now supports VNAs with up to 8 ports
   - Capsulation of communication to the hardware inside of the DeviceDriver class. This simplifies the integration of drivers for other equipment
@@ -56,7 +76,7 @@
 ## v1.3.0
 
 Some new software features along with a few bug fixes.
-  
+
 - New features:
   - Allow multiple VNA/Signal generator/Spectrum analyzer tabs
   - Software work-around to allow up to 65535 points per sweep
diff --git a/FPGA/VNA/MCP33131.vhd b/FPGA/VNA/MCP33131.vhd
index 8b560c3..3419a81 100644
--- a/FPGA/VNA/MCP33131.vhd
+++ b/FPGA/VNA/MCP33131.vhd
@@ -42,15 +42,16 @@ entity MCP33131 is
 			  RESET_MINMAX : in STD_LOGIC;
            SDO : in  STD_LOGIC;
            CONVSTART : out  STD_LOGIC;
-           SCLK : out  STD_LOGIC);
+           SCLK : inout  STD_LOGIC);
 end MCP33131;
 
 architecture Behavioral of MCP33131 is
 	signal conv_cnt : integer range 0 to CONVCYCLES-1;
 	signal div_cnt : integer range 0 to (CLK_DIV/2)-1;
+	signal bit_cnt : integer range 0 to 15;
 	signal sclk_phase : std_logic;
 	signal adc_data : std_logic_vector(15 downto 0);
-	type States is (Idle, Conversion, WAIT_tEN, Transmission);
+	type States is (Idle, Conversion, WAIT_tEN, Transmission, Done);
 	signal state : States;
 	signal min_int, max_int, data_int : signed(15 downto 0);
 begin
@@ -58,6 +59,14 @@ begin
 	MIN <= std_logic_vector(min_int);
 	MAX <= std_logic_vector(max_int);
 	DATA <= std_logic_vector(data_int);
+	SCLK <= sclk_phase;
+
+	process(SCLK)
+	begin
+		if(falling_edge(SCLK)) then
+			adc_data <= adc_data(14 downto 0) & SDO;
+		end if;
+	end process;
 
 	process(CLK, RESET)
 	begin
@@ -70,6 +79,7 @@ begin
 				CONVSTART <= '0';
 				conv_cnt <= 0;
 				div_cnt <= 0;
+				bit_cnt <= 0;
 				min_int <= to_signed(32767, 16);
 				max_int <= to_signed(-32768, 16);
 			else
@@ -86,8 +96,8 @@ begin
 				end if;
 				case state is
 					when Idle =>
-						SCLK <= '0';
 						READY <= '0';
+						bit_cnt <= 0;
 						if START = '1' then
 							state <= Conversion;
 							conv_cnt <= 0;
@@ -99,7 +109,6 @@ begin
 						else
 							div_cnt <= 0;
 							CONVSTART <= '0';
-							adc_data <= "0000000000000001";
 							state <= WAIT_tEN;
 						end if;
 					when WAIT_tEN =>
@@ -110,22 +119,20 @@ begin
 						else
 							if(sclk_phase = '0') then
 								sclk_phase <= '1';
-								SCLK <= '1';
 							else
 								sclk_phase <= '0';
-								SCLK <= '0';
-								if(adc_data(15) = '0') then
-									-- not the last bit yet
-									adc_data <= adc_data(14 downto 0) & SDO;
+								if bit_cnt = 15 then
+									state <= Done;
 								else
-									-- last bit, move to output and indicate ready state
-									data_int <= signed(adc_data(14 downto 0) & SDO);
-									READY <= '1';
-									state <= Idle;
+									bit_cnt <= bit_cnt + 1;
 								end if;
 							end if;
 							div_cnt <= 0;
 						end if;
+					when Done =>
+						data_int <= signed(adc_data);
+						READY <= '1';
+						state <= Idle;
 				end case;
 			end if;
 		end if;
diff --git a/FPGA/VNA/Test_MCP33131.vhd b/FPGA/VNA/Test_MCP33131.vhd
index ed1c257..c3f8214 100644
--- a/FPGA/VNA/Test_MCP33131.vhd
+++ b/FPGA/VNA/Test_MCP33131.vhd
@@ -53,7 +53,7 @@ ARCHITECTURE behavior OF Test_MCP33131 IS
 			RESET_MINMAX : in STD_LOGIC;
          SDO : IN  std_logic;
          CONVSTART : OUT  std_logic;
-         SCLK : OUT  std_logic
+         SCLK : INOUT  std_logic
         );
     END COMPONENT;
     
diff --git a/FPGA/VNA/VNA.gise b/FPGA/VNA/VNA.gise
index 52ca488..1766d7a 100644
--- a/FPGA/VNA/VNA.gise
+++ b/FPGA/VNA/VNA.gise
@@ -41,7 +41,9 @@
     <file xil_pn:fileType="FILE_VHDL_INSTTEMPLATE" xil_pn:name="Synchronizer.vhi"/>
     <file xil_pn:branch="BehavioralSim" xil_pn:fileType="FILE_ISIM_EXE" xil_pn:name="Test_DFT_isim_beh.exe"/>
     <file xil_pn:branch="BehavioralSim" xil_pn:fileType="FILE_ISIM_EXE" xil_pn:name="Test_MAX2871_isim_beh.exe"/>
+    <file xil_pn:fileType="FILE_XST_PROJECT" xil_pn:name="Test_MCP33131_beh.prj"/>
     <file xil_pn:branch="BehavioralSim" xil_pn:fileType="FILE_ISIM_EXE" xil_pn:name="Test_MCP33131_isim_beh.exe"/>
+    <file xil_pn:fileType="FILE_ISIM_MISC" xil_pn:name="Test_MCP33131_isim_beh.wdb"/>
     <file xil_pn:branch="BehavioralSim" xil_pn:fileType="FILE_ISIM_EXE" xil_pn:name="Test_PLL_isim_beh.exe"/>
     <file xil_pn:branch="BehavioralSim" xil_pn:fileType="FILE_ISIM_EXE" xil_pn:name="Test_SPICommands_isim_beh.exe"/>
     <file xil_pn:branch="BehavioralSim" xil_pn:fileType="FILE_ISIM_EXE" xil_pn:name="Test_SPI_isim_beh.exe"/>
@@ -135,7 +137,7 @@
       <status xil_pn:value="SuccessfullyRun"/>
       <status xil_pn:value="ReadyToRun"/>
     </transform>
-    <transform xil_pn:end_ts="1604764195" xil_pn:in_ck="-3235419683908193302" xil_pn:name="TRAN_copyAbstractToPostAbstractSimulation" xil_pn:start_ts="1604764195">
+    <transform xil_pn:end_ts="1708955295" xil_pn:in_ck="-3235419683908193302" xil_pn:name="TRAN_copyAbstractToPostAbstractSimulation" xil_pn:start_ts="1708955295">
       <status xil_pn:value="SuccessfullyRun"/>
       <status xil_pn:value="ReadyToRun"/>
       <status xil_pn:value="OutOfDateForInputs"/>
@@ -165,56 +167,87 @@
       <outfile xil_pn:name="top.vhd"/>
       <outfile xil_pn:name="window.vhd"/>
     </transform>
-    <transform xil_pn:end_ts="1604764128" xil_pn:name="TRAN_xawsToSimhdl" xil_pn:prop_ck="3044368668303368987" xil_pn:start_ts="1604764128">
+    <transform xil_pn:end_ts="1708955295" xil_pn:name="TRAN_xawsToSimhdl" xil_pn:prop_ck="-1206566934435318832" xil_pn:start_ts="1708955295">
       <status xil_pn:value="SuccessfullyRun"/>
       <status xil_pn:value="ReadyToRun"/>
     </transform>
-    <transform xil_pn:end_ts="1604764128" xil_pn:name="TRAN_schematicsToHdlSim" xil_pn:prop_ck="-7898843873652552295" xil_pn:start_ts="1604764128">
+    <transform xil_pn:end_ts="1708955295" xil_pn:name="TRAN_schematicsToHdlSim" xil_pn:prop_ck="-273551377395144626" xil_pn:start_ts="1708955295">
       <status xil_pn:value="SuccessfullyRun"/>
       <status xil_pn:value="ReadyToRun"/>
     </transform>
-    <transform xil_pn:end_ts="1604763670" xil_pn:in_ck="6306144844996157057" xil_pn:name="TRAN_regenerateCoresSim" xil_pn:prop_ck="-2723611991789822717" xil_pn:start_ts="1604763670">
+    <transform xil_pn:end_ts="1708955295" xil_pn:in_ck="-4366097307991745463" xil_pn:name="TRAN_regenerateCoresSim" xil_pn:prop_ck="-2723611991789822717" xil_pn:start_ts="1708955295">
       <status xil_pn:value="SuccessfullyRun"/>
       <status xil_pn:value="ReadyToRun"/>
-      <status xil_pn:value="OutOfDateForInputs"/>
-      <status xil_pn:value="OutOfDateForOutputs"/>
-      <status xil_pn:value="InputChanged"/>
-      <status xil_pn:value="InputRemoved"/>
-      <status xil_pn:value="OutputRemoved"/>
+      <outfile xil_pn:name="ipcore_dir/DSP_SLICE.ngc"/>
+      <outfile xil_pn:name="ipcore_dir/DSP_SLICE.vhd"/>
+      <outfile xil_pn:name="ipcore_dir/PLL.vhd"/>
+      <outfile xil_pn:name="ipcore_dir/SinCos.ngc"/>
+      <outfile xil_pn:name="ipcore_dir/SinCos.vhd"/>
+      <outfile xil_pn:name="ipcore_dir/SweepConfigMem.ngc"/>
+      <outfile xil_pn:name="ipcore_dir/SweepConfigMem.vhd"/>
+      <outfile xil_pn:name="ipcore_dir/result_bram.ngc"/>
+      <outfile xil_pn:name="ipcore_dir/result_bram.vhd"/>
     </transform>
-    <transform xil_pn:end_ts="1604764195" xil_pn:in_ck="-9185925483828391381" xil_pn:name="TRAN_copyPostAbstractToPreSimulation" xil_pn:start_ts="1604764195">
+    <transform xil_pn:end_ts="1708955295" xil_pn:in_ck="-9185925483828391381" xil_pn:name="TRAN_copyPostAbstractToPreSimulation" xil_pn:start_ts="1708955295">
       <status xil_pn:value="SuccessfullyRun"/>
       <status xil_pn:value="ReadyToRun"/>
       <status xil_pn:value="OutOfDateForInputs"/>
       <status xil_pn:value="OutOfDateForPredecessor"/>
       <status xil_pn:value="OutOfDateForOutputs"/>
       <status xil_pn:value="InputChanged"/>
-      <status xil_pn:value="InputRemoved"/>
-      <status xil_pn:value="OutputRemoved"/>
-    </transform>
-    <transform xil_pn:end_ts="1604764196" xil_pn:in_ck="4954137158046299803" xil_pn:name="TRAN_ISimulateBehavioralModelRunFuse" xil_pn:prop_ck="3520630626282717961" xil_pn:start_ts="1604764195">
-      <status xil_pn:value="SuccessfullyRun"/>
-      <status xil_pn:value="ReadyToRun"/>
-      <status xil_pn:value="OutOfDateForInputs"/>
-      <status xil_pn:value="OutOfDateForProperties"/>
-      <status xil_pn:value="OutOfDateForPredecessor"/>
-      <status xil_pn:value="OutOfDateForOutputs"/>
-      <status xil_pn:value="InputAdded"/>
-      <status xil_pn:value="InputChanged"/>
-      <status xil_pn:value="InputRemoved"/>
       <status xil_pn:value="OutputChanged"/>
-      <status xil_pn:value="OutputRemoved"/>
+      <outfile xil_pn:name="DFT.vhd"/>
+      <outfile xil_pn:name="MAX2871.vhd"/>
+      <outfile xil_pn:name="MCP33131.vhd"/>
+      <outfile xil_pn:name="ResetDelay.vhd"/>
+      <outfile xil_pn:name="SPIConfig.vhd"/>
+      <outfile xil_pn:name="Sampling.vhd"/>
+      <outfile xil_pn:name="Sweep.vhd"/>
+      <outfile xil_pn:name="Synchronizer.vhd"/>
+      <outfile xil_pn:name="Test_DFT.vhd"/>
+      <outfile xil_pn:name="Test_MAX2871.vhd"/>
+      <outfile xil_pn:name="Test_MCP33131.vhd"/>
+      <outfile xil_pn:name="Test_PLL.vhd"/>
+      <outfile xil_pn:name="Test_SPI.vhd"/>
+      <outfile xil_pn:name="Test_SPICommands.vhd"/>
+      <outfile xil_pn:name="Test_Sampling.vhd"/>
+      <outfile xil_pn:name="Test_SinCos.vhd"/>
+      <outfile xil_pn:name="Test_Window.vhd"/>
+      <outfile xil_pn:name="Test_Windowing.vhd"/>
+      <outfile xil_pn:name="Windowing.vhd"/>
+      <outfile xil_pn:name="ipcore_dir/DSP_SLICE.vhd"/>
+      <outfile xil_pn:name="ipcore_dir/PLL.vhd"/>
+      <outfile xil_pn:name="ipcore_dir/SinCos.vhd"/>
+      <outfile xil_pn:name="ipcore_dir/SweepConfigMem.vhd"/>
+      <outfile xil_pn:name="ipcore_dir/result_bram.vhd"/>
+      <outfile xil_pn:name="spi_slave.vhd"/>
+      <outfile xil_pn:name="top.vhd"/>
+      <outfile xil_pn:name="window.vhd"/>
     </transform>
-    <transform xil_pn:end_ts="1604764196" xil_pn:in_ck="-6978407093755538946" xil_pn:name="TRAN_ISimulateBehavioralModel" xil_pn:prop_ck="-8357625476205656394" xil_pn:start_ts="1604764196">
+    <transform xil_pn:end_ts="1708955298" xil_pn:in_ck="-9185925483828391381" xil_pn:name="TRAN_ISimulateBehavioralModelRunFuse" xil_pn:prop_ck="-3530939538078141760" xil_pn:start_ts="1708955295">
       <status xil_pn:value="SuccessfullyRun"/>
       <status xil_pn:value="ReadyToRun"/>
       <status xil_pn:value="OutOfDateForInputs"/>
-      <status xil_pn:value="OutOfDateForProperties"/>
       <status xil_pn:value="OutOfDateForPredecessor"/>
       <status xil_pn:value="OutOfDateForOutputs"/>
-      <status xil_pn:value="InputRemoved"/>
+      <status xil_pn:value="InputChanged"/>
       <status xil_pn:value="OutputChanged"/>
-      <status xil_pn:value="OutputRemoved"/>
+      <outfile xil_pn:name="Test_MCP33131_beh.prj"/>
+      <outfile xil_pn:name="Test_MCP33131_isim_beh.exe"/>
+      <outfile xil_pn:name="fuse.log"/>
+      <outfile xil_pn:name="isim"/>
+      <outfile xil_pn:name="isim.log"/>
+      <outfile xil_pn:name="xilinxsim.ini"/>
+    </transform>
+    <transform xil_pn:end_ts="1708955298" xil_pn:in_ck="4191604156099045257" xil_pn:name="TRAN_ISimulateBehavioralModel" xil_pn:prop_ck="6352116336892055917" xil_pn:start_ts="1708955298">
+      <status xil_pn:value="SuccessfullyRun"/>
+      <status xil_pn:value="ReadyToRun"/>
+      <status xil_pn:value="OutOfDateForPredecessor"/>
+      <status xil_pn:value="OutOfDateForOutputs"/>
+      <status xil_pn:value="OutputChanged"/>
+      <outfile xil_pn:name="Test_MCP33131_isim_beh.wdb"/>
+      <outfile xil_pn:name="isim.cmd"/>
+      <outfile xil_pn:name="isim.log"/>
     </transform>
     <transform xil_pn:end_ts="1600270761" xil_pn:name="TRAN_copyInitialToXSTAbstractSynthesis" xil_pn:start_ts="1600270761">
       <status xil_pn:value="SuccessfullyRun"/>
@@ -224,7 +257,7 @@
       <status xil_pn:value="SuccessfullyRun"/>
       <status xil_pn:value="ReadyToRun"/>
     </transform>
-    <transform xil_pn:end_ts="1667776201" xil_pn:in_ck="-4366097307991745463" xil_pn:name="TRAN_regenerateCores" xil_pn:prop_ck="-2723611991789822717" xil_pn:start_ts="1667776201">
+    <transform xil_pn:end_ts="1708953094" xil_pn:in_ck="-4366097307991745463" xil_pn:name="TRAN_regenerateCores" xil_pn:prop_ck="-2723611991789822717" xil_pn:start_ts="1708953094">
       <status xil_pn:value="SuccessfullyRun"/>
       <status xil_pn:value="ReadyToRun"/>
       <outfile xil_pn:name="ipcore_dir/DSP_SLICE.ngc"/>
@@ -253,7 +286,7 @@
       <status xil_pn:value="SuccessfullyRun"/>
       <status xil_pn:value="ReadyToRun"/>
     </transform>
-    <transform xil_pn:end_ts="1667776245" xil_pn:in_ck="2241500006820465658" xil_pn:name="TRANEXT_xstsynthesize_spartan6" xil_pn:prop_ck="3256065936432453276" xil_pn:start_ts="1667776235">
+    <transform xil_pn:end_ts="1708958126" xil_pn:in_ck="2241500006820465658" xil_pn:name="TRANEXT_xstsynthesize_spartan6" xil_pn:prop_ck="3256065936432453276" xil_pn:start_ts="1708958116">
       <status xil_pn:value="SuccessfullyRun"/>
       <status xil_pn:value="WarningsGenerated"/>
       <status xil_pn:value="ReadyToRun"/>
@@ -271,11 +304,11 @@
       <outfile xil_pn:name="webtalk_pn.xml"/>
       <outfile xil_pn:name="xst"/>
     </transform>
-    <transform xil_pn:end_ts="1659800190" xil_pn:in_ck="934418963425178690" xil_pn:name="TRAN_compileBCD2" xil_pn:prop_ck="6693835875156060939" xil_pn:start_ts="1659800190">
+    <transform xil_pn:end_ts="1708952937" xil_pn:in_ck="934418963425178690" xil_pn:name="TRAN_compileBCD2" xil_pn:prop_ck="6693835875156060939" xil_pn:start_ts="1708952937">
       <status xil_pn:value="SuccessfullyRun"/>
       <status xil_pn:value="ReadyToRun"/>
     </transform>
-    <transform xil_pn:end_ts="1667776248" xil_pn:in_ck="5411862124762956458" xil_pn:name="TRANEXT_ngdbuild_FPGA" xil_pn:prop_ck="4604875190571501774" xil_pn:start_ts="1667776245">
+    <transform xil_pn:end_ts="1708958131" xil_pn:in_ck="5411862124762956458" xil_pn:name="TRANEXT_ngdbuild_FPGA" xil_pn:prop_ck="4604875190571501774" xil_pn:start_ts="1708958126">
       <status xil_pn:value="SuccessfullyRun"/>
       <status xil_pn:value="ReadyToRun"/>
       <outfile xil_pn:name="_ngo"/>
@@ -284,7 +317,7 @@
       <outfile xil_pn:name="top.ngd"/>
       <outfile xil_pn:name="top_ngdbuild.xrpt"/>
     </transform>
-    <transform xil_pn:end_ts="1667776396" xil_pn:in_ck="8512332261572065657" xil_pn:name="TRANEXT_map_spartan6" xil_pn:prop_ck="-4668962392366239264" xil_pn:start_ts="1667776248">
+    <transform xil_pn:end_ts="1708958154" xil_pn:in_ck="8512332261572065657" xil_pn:name="TRANEXT_map_spartan6" xil_pn:prop_ck="-4668962392366239264" xil_pn:start_ts="1708958131">
       <status xil_pn:value="SuccessfullyRun"/>
       <status xil_pn:value="WarningsGenerated"/>
       <status xil_pn:value="ReadyToRun"/>
@@ -298,7 +331,7 @@
       <outfile xil_pn:name="top_summary.xml"/>
       <outfile xil_pn:name="top_usage.xml"/>
     </transform>
-    <transform xil_pn:end_ts="1667776409" xil_pn:in_ck="1117507038335044978" xil_pn:name="TRANEXT_par_spartan6" xil_pn:prop_ck="-1085068593928086116" xil_pn:start_ts="1667776396">
+    <transform xil_pn:end_ts="1708958170" xil_pn:in_ck="1117507038335044978" xil_pn:name="TRANEXT_par_spartan6" xil_pn:prop_ck="-1085068593928086116" xil_pn:start_ts="1708958154">
       <status xil_pn:value="SuccessfullyRun"/>
       <status xil_pn:value="ReadyToRun"/>
       <outfile xil_pn:name="_xmsgs/par.xmsgs"/>
@@ -312,7 +345,7 @@
       <outfile xil_pn:name="top_pad.txt"/>
       <outfile xil_pn:name="top_par.xrpt"/>
     </transform>
-    <transform xil_pn:end_ts="1667776416" xil_pn:in_ck="154288912438" xil_pn:name="TRANEXT_bitFile_spartan6" xil_pn:prop_ck="3274353840855015246" xil_pn:start_ts="1667776409">
+    <transform xil_pn:end_ts="1708958180" xil_pn:in_ck="154288912438" xil_pn:name="TRANEXT_bitFile_spartan6" xil_pn:prop_ck="3274353840855015246" xil_pn:start_ts="1708958170">
       <status xil_pn:value="SuccessfullyRun"/>
       <status xil_pn:value="ReadyToRun"/>
       <outfile xil_pn:name="_xmsgs/bitgen.xmsgs"/>
@@ -365,7 +398,7 @@
       <status xil_pn:value="InputChanged"/>
       <status xil_pn:value="InputRemoved"/>
     </transform>
-    <transform xil_pn:end_ts="1667776409" xil_pn:in_ck="8512326635937592693" xil_pn:name="TRAN_postRouteTrce" xil_pn:prop_ck="445577401284416184" xil_pn:start_ts="1667776405">
+    <transform xil_pn:end_ts="1708958170" xil_pn:in_ck="8512326635937592693" xil_pn:name="TRAN_postRouteTrce" xil_pn:prop_ck="445577401284416184" xil_pn:start_ts="1708958166">
       <status xil_pn:value="SuccessfullyRun"/>
       <status xil_pn:value="ReadyToRun"/>
       <outfile xil_pn:name="_xmsgs/trce.xmsgs"/>
diff --git a/FPGA/VNA/VNA.xise b/FPGA/VNA/VNA.xise
index 23fe1cf..9864992 100644
--- a/FPGA/VNA/VNA.xise
+++ b/FPGA/VNA/VNA.xise
@@ -23,11 +23,11 @@
       <association xil_pn:name="Implementation" xil_pn:seqID="0"/>
     </file>
     <file xil_pn:name="MCP33131.vhd" xil_pn:type="FILE_VHDL">
-      <association xil_pn:name="BehavioralSimulation" xil_pn:seqID="0"/>
+      <association xil_pn:name="BehavioralSimulation" xil_pn:seqID="1"/>
       <association xil_pn:name="Implementation" xil_pn:seqID="12"/>
     </file>
     <file xil_pn:name="Test_MCP33131.vhd" xil_pn:type="FILE_VHDL">
-      <association xil_pn:name="BehavioralSimulation" xil_pn:seqID="0"/>
+      <association xil_pn:name="BehavioralSimulation" xil_pn:seqID="2"/>
       <association xil_pn:name="PostMapSimulation" xil_pn:seqID="5"/>
       <association xil_pn:name="PostRouteSimulation" xil_pn:seqID="5"/>
       <association xil_pn:name="PostTranslateSimulation" xil_pn:seqID="5"/>
@@ -109,7 +109,7 @@
       <association xil_pn:name="Implementation" xil_pn:seqID="7"/>
     </file>
     <file xil_pn:name="window.vhd" xil_pn:type="FILE_VHDL">
-      <association xil_pn:name="BehavioralSimulation" xil_pn:seqID="1"/>
+      <association xil_pn:name="BehavioralSimulation" xil_pn:seqID="0"/>
       <association xil_pn:name="Implementation" xil_pn:seqID="1"/>
     </file>
     <file xil_pn:name="Test_Window.vhd" xil_pn:type="FILE_VHDL">
@@ -405,8 +405,8 @@
     <property xil_pn:name="Run for Specified Time Translate" xil_pn:value="true" xil_pn:valueState="default"/>
     <property xil_pn:name="Safe Implementation" xil_pn:value="No" xil_pn:valueState="default"/>
     <property xil_pn:name="Security" xil_pn:value="Enable Readback and Reconfiguration" xil_pn:valueState="default"/>
-    <property xil_pn:name="Selected Module Instance Name" xil_pn:value="/Test_DFT" xil_pn:valueState="non-default"/>
-    <property xil_pn:name="Selected Simulation Root Source Node Behavioral" xil_pn:value="work.Test_DFT" xil_pn:valueState="non-default"/>
+    <property xil_pn:name="Selected Module Instance Name" xil_pn:value="/Test_MCP33131" xil_pn:valueState="non-default"/>
+    <property xil_pn:name="Selected Simulation Root Source Node Behavioral" xil_pn:value="work.Test_MCP33131" xil_pn:valueState="non-default"/>
     <property xil_pn:name="Selected Simulation Root Source Node Post-Map" xil_pn:value="" xil_pn:valueState="default"/>
     <property xil_pn:name="Selected Simulation Root Source Node Post-Route" xil_pn:value="" xil_pn:valueState="default"/>
     <property xil_pn:name="Selected Simulation Root Source Node Post-Translate" xil_pn:value="" xil_pn:valueState="default"/>
@@ -424,7 +424,7 @@
     <property xil_pn:name="Simulator" xil_pn:value="ISim (VHDL/Verilog)" xil_pn:valueState="default"/>
     <property xil_pn:name="Slice Utilization Ratio" xil_pn:value="100" xil_pn:valueState="default"/>
     <property xil_pn:name="Specify 'define Macro Name and Value" xil_pn:value="" xil_pn:valueState="default"/>
-    <property xil_pn:name="Specify Top Level Instance Names Behavioral" xil_pn:value="work.Test_DFT" xil_pn:valueState="default"/>
+    <property xil_pn:name="Specify Top Level Instance Names Behavioral" xil_pn:value="work.Test_MCP33131" xil_pn:valueState="default"/>
     <property xil_pn:name="Specify Top Level Instance Names Post-Map" xil_pn:value="Default" xil_pn:valueState="default"/>
     <property xil_pn:name="Specify Top Level Instance Names Post-Route" xil_pn:value="Default" xil_pn:valueState="default"/>
     <property xil_pn:name="Specify Top Level Instance Names Post-Translate" xil_pn:value="Default" xil_pn:valueState="default"/>
@@ -476,7 +476,7 @@
     <!--                                                                                  -->
     <!-- The following properties are for internal use only. These should not be modified.-->
     <!--                                                                                  -->
-    <property xil_pn:name="PROP_BehavioralSimTop" xil_pn:value="Architecture|window|Behavioral" xil_pn:valueState="non-default"/>
+    <property xil_pn:name="PROP_BehavioralSimTop" xil_pn:value="Architecture|Test_MCP33131|behavior" xil_pn:valueState="non-default"/>
     <property xil_pn:name="PROP_DesignName" xil_pn:value="VNA" xil_pn:valueState="non-default"/>
     <property xil_pn:name="PROP_DevFamilyPMName" xil_pn:value="spartan6" xil_pn:valueState="default"/>
     <property xil_pn:name="PROP_FPGAConfiguration" xil_pn:value="FPGAConfiguration" xil_pn:valueState="default"/>
diff --git a/FPGA/VNA/top.bin b/FPGA/VNA/top.bin
index 5292ff7..c7fda7e 100644
Binary files a/FPGA/VNA/top.bin and b/FPGA/VNA/top.bin differ
diff --git a/FPGA/VNA/top.vhd b/FPGA/VNA/top.vhd
index ba5f8b1..70309ce 100644
--- a/FPGA/VNA/top.vhd
+++ b/FPGA/VNA/top.vhd
@@ -44,12 +44,12 @@ entity top is
 			  TRIGGER_OUT : out STD_LOGIC;
            PORT2_CONVSTART : out  STD_LOGIC;
            PORT2_SDO : in  STD_LOGIC;
-           PORT2_SCLK : out  STD_LOGIC;
+           PORT2_SCLK : inout  STD_LOGIC;
            PORT2_MIX2_EN : out  STD_LOGIC;
            PORT2_MIX1_EN : out  STD_LOGIC;
            PORT1_CONVSTART : out  STD_LOGIC;
            PORT1_SDO : in  STD_LOGIC;
-           PORT1_SCLK : out  STD_LOGIC;
+           PORT1_SCLK : inout  STD_LOGIC;
            PORT1_MIX2_EN : out  STD_LOGIC;
            PORT1_MIX1_EN : out  STD_LOGIC;
            LO1_MUX : in  STD_LOGIC;
@@ -83,7 +83,7 @@ entity top is
            SOURCE_CE : out  STD_LOGIC;
            REF_CONVSTART : out  STD_LOGIC;
            REF_SDO : in  STD_LOGIC;
-           REF_SCLK : out  STD_LOGIC);
+           REF_SCLK : inout  STD_LOGIC);
 end top;
 
 architecture Behavioral of top is
@@ -213,7 +213,7 @@ architecture Behavioral of top is
 		MAX : out STD_LOGIC_VECTOR (15 downto 0);
 		RESET_MINMAX : in STD_LOGIC;
 		CONVSTART : OUT std_logic;
-		SCLK : OUT std_logic
+		SCLK : INOUT std_logic
 		);
 	END COMPONENT;
 	COMPONENT MAX2871
diff --git a/Hardware/BOM.ods b/Hardware/BOM.ods
index aae1815..c0fc7da 100644
Binary files a/Hardware/BOM.ods and b/Hardware/BOM.ods differ
diff --git a/Hardware/Schematic.pdf b/Hardware/Schematic.pdf
index 6cc9698..15d737b 100644
Binary files a/Hardware/Schematic.pdf and b/Hardware/Schematic.pdf differ
diff --git a/Software/PC_Application/LibreVNA-GUI/Device/LibreVNA/deviceconfigurationdialogv1.ui b/Software/PC_Application/LibreVNA-GUI/Device/LibreVNA/deviceconfigurationdialogv1.ui
index a24e6a8..75f3e22 100644
--- a/Software/PC_Application/LibreVNA-GUI/Device/LibreVNA/deviceconfigurationdialogv1.ui
+++ b/Software/PC_Application/LibreVNA-GUI/Device/LibreVNA/deviceconfigurationdialogv1.ui
@@ -6,8 +6,8 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>497</width>
-    <height>297</height>
+    <width>488</width>
+    <height>364</height>
    </rect>
   </property>
   <property name="windowTitle">
diff --git a/Software/PC_Application/LibreVNA-GUI/LibreVNA-GUI.pro b/Software/PC_Application/LibreVNA-GUI/LibreVNA-GUI.pro
index 9fb18d6..e119bc7 100644
--- a/Software/PC_Application/LibreVNA-GUI/LibreVNA-GUI.pro
+++ b/Software/PC_Application/LibreVNA-GUI/LibreVNA-GUI.pro
@@ -395,5 +395,5 @@ QMAKE_CXXFLAGS += -Wno-deprecated -Wno-deprecated-declarations -Wno-deprecated-c
 CONFIG += c++17
 REVISION = $$system(git rev-parse HEAD)
 DEFINES += GITHASH=\\"\"$$REVISION\\"\"
-DEFINES += FW_MAJOR=1 FW_MINOR=5 FW_PATCH=0 FW_SUFFIX=""
+DEFINES += FW_MAJOR=1 FW_MINOR=5 FW_PATCH=1 FW_SUFFIX=""
 DEFINES -= _UNICODE UNICODE
diff --git a/Software/VNA_embedded/.cproject b/Software/VNA_embedded/.cproject
index cdf3c65..b457c0d 100644
--- a/Software/VNA_embedded/.cproject
+++ b/Software/VNA_embedded/.cproject
@@ -44,7 +44,7 @@
 									<listOptionValue builtIn="false" value="_SNK"/>
 									<listOptionValue builtIn="false" value="FW_MAJOR=1"/>
 									<listOptionValue builtIn="false" value="FW_MINOR=5"/>
-									<listOptionValue builtIn="false" value="FW_PATCH=0"/>
+									<listOptionValue builtIn="false" value="FW_PATCH=1"/>
 									<listOptionValue builtIn="false" value="HW_REVISION='B'"/>
 									<listOptionValue builtIn="false" value="USE_FULL_LL_DRIVER"/>
 									<listOptionValue builtIn="false" value="USE_HAL_DRIVER"/>
@@ -91,7 +91,7 @@
 									<listOptionValue builtIn="false" value="DEBUG"/>
 									<listOptionValue builtIn="false" value="FW_MAJOR=1"/>
 									<listOptionValue builtIn="false" value="FW_MINOR=5"/>
-									<listOptionValue builtIn="false" value="FW_PATCH=0"/>
+									<listOptionValue builtIn="false" value="FW_PATCH=1"/>
 									<listOptionValue builtIn="false" value="HW_REVISION='B'"/>
 									<listOptionValue builtIn="false" value="USE_FULL_LL_DRIVER"/>
 									<listOptionValue builtIn="false" value="USE_HAL_DRIVER"/>
@@ -302,4 +302,4 @@
 			<resource resourceType="PROJECT" workspacePath="/VNA_embedded"/>
 		</configuration>
 	</storageModule>
-</cproject>
+</cproject>
\ No newline at end of file
diff --git a/Software/VNA_embedded/Makefile b/Software/VNA_embedded/Makefile
index 0fb6706..0e74cae 100644
--- a/Software/VNA_embedded/Makefile
+++ b/Software/VNA_embedded/Makefile
@@ -101,7 +101,7 @@ MCU = $(CPU) -mthumb $(FLOAT-ABI) $(FPU)
 C_DEFS =  \
 -DFW_MAJOR=1 \
 -DFW_MINOR=5 \
--DFW_PATCH=0 \
+-DFW_PATCH=1 \
 -DDEBUG \
 -DUSE_FULL_LL_DRIVER \
 -DHW_REVISION="'B'" \
diff --git a/Software/VNA_embedded/Src/main.c b/Software/VNA_embedded/Src/main.c
index f9e790d..df77ab7 100644
--- a/Software/VNA_embedded/Src/main.c
+++ b/Software/VNA_embedded/Src/main.c
@@ -111,7 +111,7 @@ int main(void)
 
   /* USER CODE BEGIN SysInit */
   MX_I2C2_Init();
-  uint8_t ctrl = 0x0A;
+  uint8_t ctrl = 0x09;
   HAL_I2C_Mem_Write(&hi2c2, 0x42, 0x01, I2C_MEMADD_SIZE_8BIT, &ctrl, 1, 100);
   /* USER CODE END SysInit */