Merge pull request #144 from czietz/window_loss

Compensate IFFT window / zero-padding loss in TD

Makefile

@@ -81,6 +81,10 @@ endif
 # Project, sources and paths
 #
 
+# Dvice node to flash
+DEVICE = /dev/cu.usbmodem401
+#DEVICE = /dev/ttyACM0
+
 # Define project name here
 PROJECT = ch
 
@@ -225,6 +229,4 @@ flash: build/ch.bin
 	dfu-util -d 0483:df11 -a 0 -s 0x08000000:leave -D build/ch.bin
 
 dfu:
-	-@printf "reset dfu\r" >/dev/cu.usbmodem401
+	-printf "reset dfu\r" >$(DEVICE) && sleep 1
-
-

README.md

@@ -89,7 +89,7 @@ There are seveal numbers of great companion PC tools from third-party.
 
 ## Documentation
 
-* [NanoVNA User Guide](https://cho45.github.io/NanoVNA-manual/) [(google translate)](https://translate.google.com/translate?sl=ja&tl=en&u=https%3A%2F%2Fcho45.github.io%2FNanoVNA-manual%2F) by cho45
+* [NanoVNA User Guide(ja)](https://cho45.github.io/NanoVNA-manual/) by cho45. [(en:google translate)](https://translate.google.com/translate?sl=ja&tl=en&u=https%3A%2F%2Fcho45.github.io%2FNanoVNA-manual%2F)
 
 ## Reference
 
@@ -105,6 +105,7 @@ Hardware design material is disclosed to prevent bad quality clone. Please let m
 ## Authorized Distributor
 
 * [Nooelec](https://www.nooelec.com/store/nanovna-bundle.html)
+* Switch Science(ja) [NanoVNA-H](https://www.switch-science.com/catalog/6405/) [NanoVNA-H4](https://www.switch-science.com/catalog/6406/)
 
 ## Credit
 

dsp.c

@@ -41,10 +41,10 @@ const int16_t sincos_tbl[48][2] = {
   {-24636, -21605 }, {-32698,  -2143 }, {-27246,  18205 }, {-10533,  31029 }
 };
 
-int32_t acc_samp_s;
+float acc_samp_s;
-int32_t acc_samp_c;
+float acc_samp_c;
-int32_t acc_ref_s;
+float acc_ref_s;
-int32_t acc_ref_c;
+float acc_ref_c;
 
 void
 dsp_process(int16_t *capture, size_t length)
@@ -79,10 +79,10 @@ dsp_process(int16_t *capture, size_t length)
     ref_c = __SMLATT(sr, sc, ref_c);
 #endif
   }
-  acc_samp_s = samp_s;
+  acc_samp_s += samp_s;
-  acc_samp_c = samp_c;
+  acc_samp_c += samp_c;
-  acc_ref_s = ref_s;
+  acc_ref_s += ref_s;
-  acc_ref_c = ref_c;
+  acc_ref_c += ref_c;
 }
 
 void

main.c

@@ -198,40 +198,54 @@ transform_domain(void)
   // and calculate ifft for time domain
   float* tmp = (float*)spi_buffer;
 
+  // correct IFFT window and zero-padding loss
+  // assuming a 2*POINT_COUNT window
+  float wincorr = 1.0f;
+  float beta = 0.0;
+  switch (domain_mode & TD_WINDOW) {
+    case TD_WINDOW_MINIMUM:
+      beta = 0.0; // this is rectangular
+      // loss by zero-padding 202 to 256 points
+      wincorr = (float)FFT_SIZE / (float)(2*POINTS_COUNT);
+      break;
+    case TD_WINDOW_NORMAL:
+      beta = 6.0;
+      // additional window loss: 1/mean(kaiser(202,6)) = 2.01
+      wincorr = (float)FFT_SIZE / (float)(2*POINTS_COUNT) * 2.01f;
+      break;
+    case TD_WINDOW_MAXIMUM:
+      beta = 13;
+      // additional window loss: 1/mean(kaiser(202,13)) = 2.92
+      wincorr = (float)FFT_SIZE / (float)(2*POINTS_COUNT) * 2.92f;
+      break;
+  }
+
   uint8_t window_size = POINTS_COUNT, offset = 0;
   uint8_t is_lowpass = FALSE;
   switch (domain_mode & TD_FUNC) {
     case TD_FUNC_BANDPASS:
       offset = 0;
       window_size = POINTS_COUNT;
+      // window size is half the size as assumed above => twice the IFFT loss
+      wincorr *= 2.0f;
       break;
-    case TD_FUNC_LOWPASS_IMPULSE:
     case TD_FUNC_LOWPASS_STEP:
+      // no IFFT losses need to be considered to calculate the step response
+      wincorr = 1.0f;
+      // fall-through
+    case TD_FUNC_LOWPASS_IMPULSE:
       is_lowpass = TRUE;
       offset = POINTS_COUNT;
       window_size = POINTS_COUNT * 2;
       break;
   }
 
-  float beta = 0.0;
-  switch (domain_mode & TD_WINDOW) {
-    case TD_WINDOW_MINIMUM:
-      beta = 0.0;  // this is rectangular
-      break;
-    case TD_WINDOW_NORMAL:
-      beta = 6.0;
-      break;
-    case TD_WINDOW_MAXIMUM:
-      beta = 13;
-      break;
-  }
-
   for (int ch = 0; ch < 2; ch++) {
     memcpy(tmp, measured[ch], sizeof(measured[0]));
     for (int i = 0; i < POINTS_COUNT; i++) {
       float w = kaiser_window(i + offset, window_size, beta);
-      tmp[i * 2 + 0] *= w;
+      tmp[i * 2 + 0] *= w * wincorr;
-      tmp[i * 2 + 1] *= w;
+      tmp[i * 2 + 1] *= w * wincorr;
     }
     for (int i = POINTS_COUNT; i < FFT_SIZE; i++) {
       tmp[i * 2 + 0] = 0.0;
@@ -584,10 +598,34 @@ int16_t dump_buffer[AUDIO_BUFFER_LEN];
 int16_t dump_selection = 0;
 #endif
 
-volatile int16_t wait_count = 0;
+volatile uint8_t wait_count = 0;
+volatile uint8_t accumerate_count = 0;
+
+const int8_t bandwidth_accumerate_count[] = {
+  1, // 1kHz
+  3, // 300Hz
+  10, // 100Hz
+  33, // 30Hz
+  100 // 10Hz
+};
 
 float measured[2][POINTS_COUNT][2];
 
+static inline void
+dsp_start(int count)
+{
+  wait_count = count;
+  accumerate_count = bandwidth_accumerate_count[bandwidth];
+  reset_dsp_accumerator();
+}
+
+static inline void
+dsp_wait(void)
+{
+  while (accumerate_count > 0)
+    __WFI();
+}
+
 #ifdef ENABLED_DUMP
 static void
 duplicate_buffer_to_dump(int16_t *p)
@@ -610,13 +648,16 @@ void i2s_end_callback(I2SDriver *i2sp, size_t offset, size_t n)
   (void)i2sp;
   (void)n;
 
-  if (wait_count > 0) {
+  if (wait_count > 1) {
-    if (wait_count == 1) 
-      dsp_process(p, n);
-#ifdef ENABLED_DUMP
-      duplicate_buffer_to_dump(p);
-#endif
     --wait_count;
+  } else if (wait_count > 0) {
+    if (accumerate_count > 0) {
+      dsp_process(p, n);
+      accumerate_count--;
+    }
+#ifdef ENABLED_DUMP
+    duplicate_buffer_to_dump(p);
+#endif
   }
 
 #if PORT_SUPPORTS_RT
@@ -668,7 +709,8 @@ VNA_SHELL_FUNCTION(cmd_dump)
   if (argc == 1)
     dump_selection = my_atoi(argv[0]);
 
-  wait_dsp(3);
+  dsp_start(3);
+  dsp_wait();
 
   len = AUDIO_BUFFER_LEN;
   if (dump_selection == 1 || dump_selection == 2)
@@ -752,7 +794,6 @@ config_t config = {
   .trace_color =       { DEFAULT_TRACE_1_COLOR, DEFAULT_TRACE_2_COLOR, DEFAULT_TRACE_3_COLOR, DEFAULT_TRACE_4_COLOR },
 //  .touch_cal =         { 693, 605, 124, 171 },  // 2.4 inch LCD panel
   .touch_cal =         { 338, 522, 153, 192 },  // 2.8 inch LCD panel
-  .freq_mode = FREQ_MODE_START_STOP,
   .harmonic_freq_threshold = 300000000,
   .vbat_offset = 500
 };
@@ -792,6 +833,8 @@ void load_default_properties(void)
   current_props._active_marker   = 0;
   current_props._domain_mode     = 0;
   current_props._marker_smith_format = MS_RLC;
+  current_props._freq_mode = FREQ_MODE_START_STOP;
+
 //Checksum add on caldata_save
 //current_props.checksum = 0;
 }
@@ -808,9 +851,6 @@ ensure_edit_config(void)
   cal_status = 0;
 }
 
-#define DSP_START(delay) wait_count = delay;
-#define DSP_WAIT_READY   while (wait_count) __WFI();
-
 #define DELAY_CHANNEL_CHANGE 2
 
 // main loop for measurement
@@ -824,20 +864,20 @@ bool sweep(bool break_on_operation)
     if (frequencies[i] == 0) break;
     delay = set_frequency(frequencies[i]);     // 700
     tlv320aic3204_select(0);                   // 60 CH0:REFLECT, reset and begin measure
-    DSP_START(delay + ((i == 0) ? 1 : 0));     // 1900
+    dsp_start(delay + ((i == 0) ? 1 : 0));     // 1900
     //================================================
     // Place some code thats need execute while delay
     //================================================
-    DSP_WAIT_READY;
+    dsp_wait();
     // calculate reflection coefficient
     (*sample_func)(measured[0][i]);            // 60
 
     tlv320aic3204_select(1);                   // 60 CH1:TRANSMISSION, reset and begin measure
-    DSP_START(DELAY_CHANNEL_CHANGE);           // 1700
+    dsp_start(DELAY_CHANNEL_CHANGE);           // 1700
     //================================================
     // Place some code thats need execute while delay
     //================================================
-    DSP_WAIT_READY;
+    dsp_wait();
     // calculate transmission coefficient
     (*sample_func)(measured[1][i]);            // 60
                                                // ======== 170 ===========
@@ -979,7 +1019,7 @@ set_sweep_frequency(int type, uint32_t freq)
   ensure_edit_config();
   switch (type) {
     case ST_START:
-      config.freq_mode &= ~FREQ_MODE_CENTER_SPAN;
+      freq_mode &= ~FREQ_MODE_CENTER_SPAN;
       if (frequency0 != freq) {
         frequency0 = freq;
         // if start > stop then make start = stop
@@ -987,7 +1027,7 @@ set_sweep_frequency(int type, uint32_t freq)
       }
       break;
     case ST_STOP:
-      config.freq_mode &= ~FREQ_MODE_CENTER_SPAN;
+      freq_mode &= ~FREQ_MODE_CENTER_SPAN;
       if (frequency1 != freq) {
         frequency1 = freq;
         // if start > stop then make start = stop
@@ -995,7 +1035,7 @@ set_sweep_frequency(int type, uint32_t freq)
       }
       break;
     case ST_CENTER:
-      config.freq_mode |= FREQ_MODE_CENTER_SPAN;
+      freq_mode |= FREQ_MODE_CENTER_SPAN;
       uint32_t center = frequency0 / 2 + frequency1 / 2;
       if (center != freq) {
         uint32_t span = frequency1 - frequency0;
@@ -1010,7 +1050,7 @@ set_sweep_frequency(int type, uint32_t freq)
       }
       break;
     case ST_SPAN:
-      config.freq_mode |= FREQ_MODE_CENTER_SPAN;
+      freq_mode |= FREQ_MODE_CENTER_SPAN;
       if (frequency1 - frequency0 != freq) {
         uint32_t center = frequency0 / 2 + frequency1 / 2;
         if (center < START_MIN + freq / 2) {
@@ -1024,7 +1064,7 @@ set_sweep_frequency(int type, uint32_t freq)
       }
       break;
     case ST_CW:
-      config.freq_mode |= FREQ_MODE_CENTER_SPAN;
+      freq_mode |= FREQ_MODE_CENTER_SPAN;
       if (frequency0 != freq || frequency1 != freq) {
         frequency0 = freq;
         frequency1 = freq;
@@ -1524,7 +1564,8 @@ static const struct {
   { "REAL",   NGRIDY/2,  0.25 },
   { "IMAG",   NGRIDY/2,  0.25 },
   { "R",      NGRIDY/2, 100.0 },
-  { "X",      NGRIDY/2, 100.0 }
+  { "X",      NGRIDY/2, 100.0 },
+  { "Q",             0,  10.0 }
 };
 
 static const char * const trc_channel_name[] = {
@@ -1628,8 +1669,8 @@ VNA_SHELL_FUNCTION(cmd_trace)
 #if MAX_TRACE_TYPE != 12
 #error "Trace type enum possibly changed, check cmd_trace function"
 #endif
-  // enum TRC_LOGMAG, TRC_PHASE, TRC_DELAY, TRC_SMITH, TRC_POLAR, TRC_LINEAR, TRC_SWR, TRC_REAL, TRC_IMAG, TRC_R, TRC_X, TRC_OFF
+  // enum TRC_LOGMAG, TRC_PHASE, TRC_DELAY, TRC_SMITH, TRC_POLAR, TRC_LINEAR, TRC_SWR, TRC_REAL, TRC_IMAG, TRC_R, TRC_X, TRC_Q, TRC_OFF
-  static const char cmd_type_list[] = "logmag|phase|delay|smith|polar|linear|swr|real|imag|r|x|off";
+  static const char cmd_type_list[] = "logmag|phase|delay|smith|polar|linear|swr|real|imag|r|x|q|off";
   int type = get_str_index(argv[1], cmd_type_list);
   if (type >= 0) {
     set_trace_type(t, type);
@@ -1921,6 +1962,23 @@ VNA_SHELL_FUNCTION(cmd_port)
   tlv320aic3204_select(port);
 }
 
+VNA_SHELL_FUNCTION(cmd_bandwidth)
+{
+  if (argc != 1)
+    goto usage;
+
+  static const char bw_choice[] = "1000|300|100|30|10";
+  int i = get_str_index(argv[0], bw_choice);
+  if (i < 0)
+    goto usage;
+
+  bandwidth = i;
+  return;
+
+usage:
+  shell_printf("usage: bandwidth {%s}\r\n", bw_choice);
+}
+
 VNA_SHELL_FUNCTION(cmd_stat)
 {
   int16_t *p = &rx_buffer[0];
@@ -2109,6 +2167,7 @@ static const VNAShellCommand commands[] =
     {"dump"        , cmd_dump        , 0},
 #endif
     {"frequencies" , cmd_frequencies , 0},
+    {"bandwidth"   , cmd_bandwidth   , 0},
     {"port"        , cmd_port        , 0},
     {"stat"        , cmd_stat        , 0},
     {"gain"        , cmd_gain        , 0},

nanovna.h

@@ -194,10 +194,10 @@ extern const uint16_t numfont16x22[];
 
 #define MAX_TRACE_TYPE 12
 enum trace_type {
-  TRC_LOGMAG=0, TRC_PHASE, TRC_DELAY, TRC_SMITH, TRC_POLAR, TRC_LINEAR, TRC_SWR, TRC_REAL, TRC_IMAG, TRC_R, TRC_X, TRC_OFF
+  TRC_LOGMAG=0, TRC_PHASE, TRC_DELAY, TRC_SMITH, TRC_POLAR, TRC_LINEAR, TRC_SWR, TRC_REAL, TRC_IMAG, TRC_R, TRC_X, TRC_Q, TRC_OFF
 };
 // Mask for define rectangular plot
-#define RECTANGULAR_GRID_MASK ((1<<TRC_LOGMAG)|(1<<TRC_PHASE)|(1<<TRC_DELAY)|(1<<TRC_LINEAR)|(1<<TRC_SWR)|(1<<TRC_REAL)|(1<<TRC_IMAG)|(1<<TRC_R)|(1<<TRC_X))
+#define RECTANGULAR_GRID_MASK ((1<<TRC_LOGMAG)|(1<<TRC_PHASE)|(1<<TRC_DELAY)|(1<<TRC_LINEAR)|(1<<TRC_SWR)|(1<<TRC_REAL)|(1<<TRC_IMAG)|(1<<TRC_R)|(1<<TRC_X)|(1<<TRC_Q))
 
 // LOGMAG: SCALE, REFPOS, REFVAL
 // PHASE: SCALE, REFPOS, REFVAL
@@ -230,7 +230,6 @@ typedef struct config {
   uint16_t menu_active_color;
   uint16_t trace_color[TRACES_MAX];
   int16_t  touch_cal[4];
-  int8_t   freq_mode;
   uint32_t harmonic_freq_threshold;
   uint16_t vbat_offset;
   uint8_t _reserved[22];
@@ -379,7 +378,9 @@ typedef struct properties {
   int8_t _active_marker;
   uint8_t _domain_mode; /* 0bxxxxxffm : where ff: TD_FUNC m: DOMAIN_MODE */
   uint8_t _marker_smith_format;
-  uint8_t _reserved[50];
+  uint8_t _bandwidth;
+  int8_t _freq_mode;
+  uint8_t _reserved[49];
   uint32_t checksum;
 } properties_t;
 
@@ -405,9 +406,11 @@ extern properties_t current_props;
 #define domain_mode current_props._domain_mode
 #define velocity_factor current_props._velocity_factor
 #define marker_smith_format current_props._marker_smith_format
+#define bandwidth current_props._bandwidth
+#define freq_mode current_props._freq_mode
 
-#define FREQ_IS_STARTSTOP() (!(config.freq_mode&FREQ_MODE_CENTER_SPAN))
+#define FREQ_IS_STARTSTOP() (!(freq_mode & FREQ_MODE_CENTER_SPAN))
-#define FREQ_IS_CENTERSPAN() (config.freq_mode&FREQ_MODE_CENTER_SPAN)
+#define FREQ_IS_CENTERSPAN() (freq_mode & FREQ_MODE_CENTER_SPAN)
 #define FREQ_IS_CW() (frequency0 == frequency1)
 
 int caldata_save(int id);

plot.c

@@ -491,6 +491,14 @@ reactance(const float *v)
   return zi;
 }
 
+static float
+qualityfactor(const float *v)
+{
+  float i = 2*v[1];
+  float r = (1+v[0])*(1-v[0]) - v[1]*v[1];
+  return fabs(i / r);
+}
+
 static void
 cartesian_scale(float re, float im, int *xp, int *yp, float scale)
 {
@@ -567,6 +575,9 @@ trace_into_index(int t, int i, float array[POINTS_COUNT][2])
   case TRC_X:
     v-= reactance(coeff) * scale;
     break;
+  case TRC_Q:
+    v-= qualityfactor(coeff) * scale;
+    break;
   case TRC_SMITH:
   //case TRC_ADMIT:
   case TRC_POLAR:
@@ -610,7 +621,7 @@ format_smith_value(char *buf, int len, const float coeff[2], uint32_t frequency)
     break;
 
   case MS_RX:
-    plot_printf(buf, len, "%F"S_OHM"%+Fj", zr, zi);
+    plot_printf(buf, len, "%F%+Fj"S_OHM, zr, zi);
     break;
 
   case MS_RLC:
@@ -669,6 +680,10 @@ trace_get_value_string(int t, char *buf, int len, float array[POINTS_COUNT][2],
     format = "%.2F"S_OHM;
     v = gamma2reactance(coeff);
     break;
+  case TRC_Q:
+    format = "%.1f";
+    v = qualityfactor(coeff);
+    break;
   case TRC_SMITH:
     format_smith_value(buf, len, coeff, frequencies[i]);
     return;
@@ -729,6 +744,10 @@ trace_get_value_string_delta(int t, char *buf, int len, float array[POINTS_COUNT
     format = "%.2F"S_OHM;
     v = gamma2reactance(coeff);
     break;
+  case TRC_Q:
+    format = "%.1f";
+    v = qualityfactor(coeff);
+    break;
   //case TRC_ADMIT:
   case TRC_POLAR:
     plot_printf(buf, len, "%.2f%+.2fj", coeff[0], coeff[1]);

ui.c

@@ -631,6 +631,13 @@ menu_transform_filter_cb(int item, uint8_t data)
   ui_mode_normal();
 }
 
+static void
+menu_bandwidth_cb(int item)
+{
+  bandwidth = item;
+  draw_menu();
+}
+
 static void
 choose_active_marker(void)
 {
@@ -761,9 +768,11 @@ menu_marker_search_cb(int item, uint8_t data)
     break;
   case 2: /* search Left */
     i = marker_search_left(markers[active_marker].index);
+    uistat.marker_tracking = false;
     break;
   case 3: /* search right */
     i = marker_search_right(markers[active_marker].index);
+    uistat.marker_tracking = false;
     break;
   case 4: /* tracking */
     uistat.marker_tracking = !uistat.marker_tracking;
@@ -877,6 +886,7 @@ const menuitem_t menu_format2[] = {
   { MT_CALLBACK, TRC_IMAG, "IMAG", menu_format_cb },
   { MT_CALLBACK, TRC_R, "RESISTANCE", menu_format_cb },
   { MT_CALLBACK, TRC_X, "REACTANCE", menu_format_cb },
+  { MT_CALLBACK, TRC_Q, "Q FACTOR", menu_format_cb },
   { MT_CANCEL, 0, S_LARROW" BACK", NULL },
   { MT_NONE, 0, NULL, NULL } // sentinel
 };
@@ -928,12 +938,23 @@ const menuitem_t menu_transform[] = {
   { MT_NONE, 0, NULL, NULL } // sentinel
 };
 
+const menuitem_t menu_bandwidth[] = {
+  { MT_CALLBACK, 0, "1 kHz", menu_bandwidth_cb },
+  { MT_CALLBACK, 0, "300 Hz", menu_bandwidth_cb },
+  { MT_CALLBACK, 0, "100 Hz", menu_bandwidth_cb },
+  { MT_CALLBACK, 0, "30 Hz", menu_bandwidth_cb },
+  { MT_CALLBACK, 0, "10 Hz", menu_bandwidth_cb },
+  { MT_CANCEL, 0, S_LARROW" BACK", NULL },
+  { MT_NONE, 0, NULL, NULL } // sentinel
+};
+
 const menuitem_t menu_display[] = {
   { MT_SUBMENU, 0, "TRACE", menu_trace },
   { MT_SUBMENU, 0, "FORMAT", menu_format },
   { MT_SUBMENU, 0, "SCALE", menu_scale },
   { MT_SUBMENU, 0, "CHANNEL", menu_channel },
   { MT_SUBMENU, 0, "TRANSFORM", menu_transform },
+  { MT_SUBMENU, 0, "BANDWIDTH", menu_bandwidth },  
   { MT_CANCEL, 0, S_LARROW" BACK", NULL },
   { MT_NONE, 0, NULL, NULL } // sentinel
 };
@@ -985,7 +1006,7 @@ const menuitem_t menu_marker_smith[] = {
   { MT_CALLBACK, MS_LIN, "LIN", menu_marker_smith_cb },
   { MT_CALLBACK, MS_LOG, "LOG", menu_marker_smith_cb },
   { MT_CALLBACK, MS_REIM,"Re+Im", menu_marker_smith_cb },
-  { MT_CALLBACK, MS_RX,  "R+Xj", menu_marker_smith_cb },
+  { MT_CALLBACK, MS_RX,  "R+jX", menu_marker_smith_cb },
   { MT_CALLBACK, MS_RLC, "R+L/C", menu_marker_smith_cb },
   { MT_CANCEL, 0, S_LARROW" BACK", NULL },
   { MT_NONE, 0, NULL, NULL } // sentinel
@@ -1120,6 +1141,7 @@ menu_invoke(int item)
 
 #define MENU_BUTTON_WIDTH  60
 #define MENU_BUTTON_HEIGHT 30
+#define MENU_BUTTON_MAX 8
 #define NUM_INPUT_HEIGHT   30
 
 #define KP_WIDTH     48
@@ -1365,6 +1387,11 @@ menu_item_modify_attribute(const menuitem_t *menu, int item,
       *bg = DEFAULT_MENU_TEXT_COLOR;
       *fg = config.menu_normal_color;
     }
+  } else if (menu == menu_bandwidth) {
+      if (item == bandwidth) {
+        *bg = 0x0000;
+        *fg = 0xffff;
+      }
   } else if (menu == menu_transform) {
       if ((item == 0 && (domain_mode & DOMAIN_MODE) == DOMAIN_TIME)
        || (item == 1 && (domain_mode & TD_FUNC) == TD_FUNC_LOWPASS_IMPULSE)
@@ -1389,7 +1416,7 @@ static void
 draw_menu_buttons(const menuitem_t *menu)
 {
   int i = 0;
-  for (i = 0; i < 7; i++) {
+  for (i = 0; i < MENU_BUTTON_MAX; i++) {
     const char *l1, *l2;
     if (menu[i].type == MT_NONE)
       break;
@@ -1435,7 +1462,7 @@ menu_apply_touch(void)
   int i;
 
   touch_position(&touch_x, &touch_y);
-  for (i = 0; i < 7; i++) {
+  for (i = 0; i < MENU_BUTTON_MAX; i++) {
     if (menu[i].type == MT_NONE)
       break;
     if (menu[i].type == MT_BLANK)
@@ -1460,7 +1487,7 @@ draw_menu(void)
 static void
 erase_menu_buttons(void)
 {
-  ili9341_fill(320-MENU_BUTTON_WIDTH, 0, MENU_BUTTON_WIDTH, MENU_BUTTON_HEIGHT*7, DEFAULT_BG_COLOR);
+  ili9341_fill(320-MENU_BUTTON_WIDTH, 0, MENU_BUTTON_WIDTH, MENU_BUTTON_HEIGHT * MENU_BUTTON_MAX, DEFAULT_BG_COLOR);
 }
 
 static void
@@ -1478,8 +1505,8 @@ leave_ui_mode()
   } else if (ui_mode == UI_NUMERIC) {
     request_to_draw_cells_behind_numeric_input();
     erase_numeric_input();
-    draw_frequencies();
   }
+  draw_frequencies();
 }
 
 static void