diff --git a/main.c b/main.c
index 4f36108..1ce5f09 100644
--- a/main.c
+++ b/main.c
@@ -34,9 +34,11 @@
 
 #define ENABLED_DUMP
 
-static void apply_error_term(void);
 static void apply_error_term_at(int i);
+static void apply_edelay_at(int i);
 static void cal_interpolate(int s);
+void update_frequencies(void);
+void set_frequencies(uint32_t start, uint32_t stop, int16_t points);
 
 void apply_edelay_at(int i);
 void set_frequencies(uint32_t start, uint32_t stop, int16_t points);
@@ -51,7 +53,7 @@ static MUTEX_DECL(mutex);
 #define IS_HARMONIC_MODE(f) ((f) > FREQ_HARMONICS)
 
 int32_t frequency_offset = 5000;
-int32_t frequency = 10000000;
+uint32_t frequency = 10000000;
 int8_t drive_strength = DRIVE_STRENGTH_AUTO;
 int8_t sweep_enabled = TRUE;
 int8_t sweep_once = FALSE;
@@ -157,7 +159,7 @@ transform_domain(void)
   // and calculate ifft for time domain
   float* tmp = (float*)spi_buffer;
 
-  uint8_t window_size, offset;
+  uint8_t window_size = 101, offset = 0;
   uint8_t is_lowpass = FALSE;
   switch (domain_mode & TD_FUNC) {
       case TD_FUNC_BANDPASS:
@@ -291,7 +293,7 @@ static int adjust_gain(int newfreq)
   return delay;
 }
 
-int set_frequency(int freq)
+int set_frequency(uint32_t freq)
 {
     int delay = 0;
     if (frequency == freq)
@@ -796,6 +798,8 @@ update_frequencies(void)
   }
 
   set_frequencies(start, stop, sweep_points);
+  operation_requested = OP_FREQCHANGE;
+  
   update_marker_index();
   
   // set grid layout
@@ -832,7 +836,7 @@ freq_mode_centerspan(void)
 #define STOP_MAX 1500000000
 
 void
-set_sweep_frequency(int type, uint32_t freq)
+set_sweep_frequency(int type, int32_t freq)
 {
   int cal_applied = cal_status & CALSTAT_APPLY;
   switch (type) {
@@ -1115,6 +1119,7 @@ eterm_calc_et(void)
   cal_status |= CALSTAT_ET;
 }
 
+#if 0
 void apply_error_term(void)
 {
   int i;
@@ -1146,6 +1151,7 @@ void apply_error_term(void)
     measured[1][i][1] = s21ai;
   }
 }
+#endif
 
 void apply_error_term_at(int i)
 {
@@ -1176,7 +1182,7 @@ void apply_error_term_at(int i)
     measured[1][i][1] = s21ai;
 }
 
-void apply_edelay_at(int i)
+static void apply_edelay_at(int i)
 {
   float w = 2 * M_PI * electrical_delay * frequencies[i] * 1E-12;
   float s = sin(w);
@@ -2132,5 +2138,6 @@ void HardFault_Handler(void)
 
 void hard_fault_handler_c(uint32_t* sp)
 {
+  (void)sp;
   while (true) {}
 }
diff --git a/nanovna.h b/nanovna.h
index 4221e2a..7ef4672 100644
--- a/nanovna.h
+++ b/nanovna.h
@@ -71,7 +71,7 @@ enum {
   ST_START, ST_STOP, ST_CENTER, ST_SPAN, ST_CW
 };
 
-void set_sweep_frequency(int type, uint32_t frequency);
+void set_sweep_frequency(int type, int32_t frequency);
 uint32_t get_sweep_frequency(int type);
 
 float my_atof(const char *p);
@@ -86,6 +86,9 @@ extern int8_t sweep_enabled;
 extern void ui_init(void);
 extern void ui_process(void);
 
+enum { OP_NONE = 0, OP_LEVER, OP_TOUCH, OP_FREQCHANGE };
+extern uint8_t operation_requested;
+
 /*
  * dsp.c
  */
@@ -106,7 +109,7 @@ void calculate_gamma(float *gamma);
 void fetch_amplitude(float *gamma);
 void fetch_amplitude_ref(float *gamma);
 
-int si5351_set_frequency_with_offset(int freq, int offset, uint8_t drive_strength);
+int si5351_set_frequency_with_offset(uint32_t freq, int offset, uint8_t drive_strength);
 
 
 /*
@@ -195,7 +198,7 @@ typedef struct {
   uint16_t trace_color[TRACES_MAX];
   int16_t touch_cal[4];
   int8_t default_loadcal;
-  int32_t harmonic_freq_threshold;
+  uint32_t harmonic_freq_threshold;
   int32_t checksum;
 } config_t;
 
@@ -237,6 +240,7 @@ void redraw_marker(int marker, int update_info);
 void trace_get_info(int t, char *buf, int len);
 void plot_into_index(float measured[2][101][2]);
 void force_set_markmap(void);
+void draw_frequencies(void);
 void draw_all(bool flush);
 
 void draw_cal_status(void);
@@ -361,6 +365,8 @@ void ui_hide(void);
 
 extern uint8_t operation_requested;
 
+void touch_start_watchdog(void);
+void touch_position(int *x, int *y);
 void handle_touch_interrupt(void);
 
 #define TOUCH_THRESHOLD 2000
diff --git a/plot.c b/plot.c
index 5815b09..a447e42 100644
--- a/plot.c
+++ b/plot.c
@@ -8,7 +8,6 @@
 #define SWAP(x,y) do { int z=x; x = y; y = z; } while(0)
 
 static void cell_draw_marker_info(int m, int n, int w, int h);
-void draw_frequencies(void);
 void frequency_string(char *buf, size_t len, int32_t freq);
 void markmap_all_markers(void);
 
@@ -658,7 +657,7 @@ gamma2imp(char *buf, int len, const float coeff[2], uint32_t frequency)
 }
 
 static void
-gamma2resistance(char *buf, int len, const float coeff[2], uint32_t frequency)
+gamma2resistance(char *buf, int len, const float coeff[2])
 {
   float z0 = 50;
   float d = z0 / ((1-coeff[0])*(1-coeff[0])+coeff[1]*coeff[1]);
@@ -667,7 +666,7 @@ gamma2resistance(char *buf, int len, const float coeff[2], uint32_t frequency)
 }
 
 static void
-gamma2reactance(char *buf, int len, const float coeff[2], uint32_t frequency)
+gamma2reactance(char *buf, int len, const float coeff[2])
 {
   float z0 = 50;
   float d = z0 / ((1-coeff[0])*(1-coeff[0])+coeff[1]*coeff[1]);
@@ -714,10 +713,10 @@ static void trace_get_value_string(
     chsnprintf(buf, len, "%.3fj", coeff[i][1]);
     break;
   case TRC_R:
-    gamma2resistance(buf, len, coeff[i], freq[i]);
+    gamma2resistance(buf, len, coeff[i]);
     break;
   case TRC_X:
-    gamma2reactance(buf, len, coeff[i], freq[i]);
+    gamma2reactance(buf, len, coeff[i]);
     break;
   //case TRC_ADMIT:
   case TRC_POLAR:
@@ -793,7 +792,7 @@ clear_markmap(void)
   memset(markmap[current_mappage], 0, sizeof markmap[current_mappage]);
 }
 
-void inline
+inline void
 force_set_markmap(void)
 {
   memset(markmap[current_mappage], 0xff, sizeof markmap[current_mappage]);
diff --git a/si5351.c b/si5351.c
index 6e57ffa..559a459 100644
--- a/si5351.c
+++ b/si5351.c
@@ -330,7 +330,7 @@ int current_band = -1;
  * CLK2: fixed 8MHz
  */
 #define CLK2_FREQUENCY 8000000L
-int si5351_set_frequency_with_offset(int freq, int offset, uint8_t drive_strength)
+int si5351_set_frequency_with_offset(uint32_t freq, int offset, uint8_t drive_strength)
 {
   int band;
   int delay = 3;
diff --git a/ui.c b/ui.c
index 21e2e3d..6f20861 100644
--- a/ui.c
+++ b/ui.c
@@ -20,6 +20,7 @@
 
 #include "ch.h"
 #include "hal.h"
+#include "chprintf.h"
 #include "nanovna.h"
 #include <stdlib.h>
 #include <string.h>
@@ -58,7 +59,6 @@ static uint32_t last_button_down_ticks;
 static uint32_t last_button_repeat_ticks;
 static int8_t inhibit_until_release = FALSE;
 
-enum { OP_NONE = 0, OP_LEVER, OP_TOUCH };
 uint8_t operation_requested = OP_NONE;
 
 int8_t previous_marker = -1;