diff --git a/F3:F303/NitrogenFlooding/BMP280.c b/F3:F303/NitrogenFlooding/BMP280.c
index 7cf963d..8981e74 100644
--- a/F3:F303/NitrogenFlooding/BMP280.c
+++ b/F3:F303/NitrogenFlooding/BMP280.c
@@ -45,14 +45,14 @@
 
 #include "i2c.h"
 #include "BMP280.h"
-
-#include <math.h>
-
+#include "usb.h"
 #ifdef EBUG
 #include "strfunc.h"
-#include "usb.h"
+extern volatile uint32_t Tms;
 #endif
 
+#include <math.h>
+
 #define BMP280_I2C_ADDRESS_MASK (0x76)
 #define BMP280_I2C_ADDRESS_0  (0x76)
 #define BMP280_I2C_ADDRESS_1  (0x77)
@@ -338,7 +338,6 @@ int BMP280_getdata(float *T, float *P, float *H){
     uint8_t data[8];
     uint8_t datasz = 8; // amount of bytes to read
     if(params.ID != BME280_CHIP_ID){
-        DBG("Not BME!\n");
         if(H) *H = 0;
         H = NULL;
         datasz = 6;
diff --git a/F3:F303/NitrogenFlooding/adc.c b/F3:F303/NitrogenFlooding/adc.c
index 1f84b63..84c2968 100644
--- a/F3:F303/NitrogenFlooding/adc.c
+++ b/F3:F303/NitrogenFlooding/adc.c
@@ -17,9 +17,6 @@
  */
 
 #include "adc.h"
-#ifdef EBUG
-#include "proto.h"
-#endif
 
 /**
  * @brief ADCx_array - arrays for ADC channels with median filtering:
@@ -127,9 +124,6 @@ uint16_t getADCval(int nch){
     PIX_SORT(p[4], p[2]) ;
 #undef PIX_SORT
 #undef PIX_SWAP
-#ifdef EBUG
-    DBG("val: "); printu(p[4]); newline();
-#endif
     return p[4];
 }
 
@@ -137,9 +131,6 @@ uint16_t getADCval(int nch){
 float getADCvoltage(int nch){
     float v = getADCval(nch) * 3.3;
     v /= 4096.f; // 12bit ADC
-#ifdef EBUG
-    DBG("v="); printf(v); newline();
-#endif
     return v;
 }
 
@@ -151,8 +142,5 @@ float getMCUtemp(){
     temperature *= (110.f - 30.f);
     temperature /= (float)(*TEMP110_CAL_ADDR - *TEMP30_CAL_ADDR);
     temperature += 30.f;
-#ifdef EBUG
-    DBG("t="); printf(temperature); newline();
-#endif
     return(temperature);
 }
diff --git a/F3:F303/NitrogenFlooding/adc.h b/F3:F303/NitrogenFlooding/adc.h
index a08e5c9..317ec39 100644
--- a/F3:F303/NitrogenFlooding/adc.h
+++ b/F3:F303/NitrogenFlooding/adc.h
@@ -25,7 +25,8 @@
 #define NUMBER_OF_ADC2_CHANNELS     (1)
 // total number of channels - for array
 #define NUMBER_OF_ADC_CHANNELS ((NUMBER_OF_ADC1_CHANNELS+NUMBER_OF_ADC2_CHANNELS))
-
+// number of AIN channels
+#define NUMBER_OF_AIN_CHANNELS      (10)
 
 // ADC1 in1..10 - inner and outern Tsens; ADC2 in1 - ext ADC
 // channels of ADC in array
diff --git a/F3:F303/NitrogenFlooding/buttons.h b/F3:F303/NitrogenFlooding/buttons.h
index f981e30..5ccf20b 100644
--- a/F3:F303/NitrogenFlooding/buttons.h
+++ b/F3:F303/NitrogenFlooding/buttons.h
@@ -37,4 +37,3 @@ extern uint32_t lastUnsleep; // last keys activity time
 void process_keys();
 keyevent keystate(uint8_t k, uint32_t *T);
 keyevent keyevt(uint8_t k);
-
diff --git a/F3:F303/NitrogenFlooding/hardware.c b/F3:F303/NitrogenFlooding/hardware.c
index 1ba7ef6..0767602 100644
--- a/F3:F303/NitrogenFlooding/hardware.c
+++ b/F3:F303/NitrogenFlooding/hardware.c
@@ -135,7 +135,7 @@ TRUE_INLINE void iwdg_setup(){
 void hw_setup(){
     RCC->AHBENR |= RCC_AHBENR_DMA1EN | RCC_AHBENR_DMA2EN;
     gpio_setup();
-    i2c_setup(LOW_SPEED);
+    i2c_setup(HIGH_SPEED);
     pwm_setup();
 #ifndef EBUG
     iwdg_setup();
diff --git a/F3:F303/NitrogenFlooding/hardware.h b/F3:F303/NitrogenFlooding/hardware.h
index fe872fc..fee3b5e 100644
--- a/F3:F303/NitrogenFlooding/hardware.h
+++ b/F3:F303/NitrogenFlooding/hardware.h
@@ -83,6 +83,19 @@
 #define BTN_ACTIVITY_TIMEOUT    (300000)
 // refresh interval for BME280 and other data  - 2.5s
 #define SENSORS_DATA_TIMEOUT    (2500)
+// refresh interval for screen windows
+#define WINDOW_REFRESH_TIMEOUT  (1000)
+
+// buttons masks bit0 - button0 etc
+#define BTN_ESC_MASK    (1<<0)
+#define BTN_LEFT_MASK   (1<<1)
+#define BTN_RIGHT_MASK  (1<<2)
+#define BTN_SEL_MASK    (1<<3)
+
+// global sensors' data
+extern float Temperature, Pressure, Humidity, Dewpoint;
+extern uint32_t Sens_measured_time;
+extern uint16_t ADCvals[];
 
 // buzzer, ADC voltage
 #define BUZZER_port     GPIOB
diff --git a/F3:F303/NitrogenFlooding/i2c.c b/F3:F303/NitrogenFlooding/i2c.c
index 881577a..e6a5367 100644
--- a/F3:F303/NitrogenFlooding/i2c.c
+++ b/F3:F303/NitrogenFlooding/i2c.c
@@ -153,12 +153,6 @@ static uint8_t write_i2cs(uint8_t addr, uint8_t *data, uint8_t nbytes, uint8_t s
         }
         I2C1->TXDR = data[i]; // send data
     }
-    cntr = Tms;
-    // wait for data gone
-    while(I2C1->ISR & I2C_ISR_BUSY){
-        IWDG->KR = IWDG_REFRESH;
-        if(Tms - cntr > I2C_TIMEOUT){break;}
-    }
     return 1;
 }
 
@@ -217,7 +211,7 @@ static uint8_t read_i2cb(uint8_t addr, uint8_t *data, uint8_t nbytes, uint8_t bu
         *data++ = I2C1->RXDR;
     }
     return 1;
- }
+}
 
 uint8_t read_i2c(uint8_t addr, uint8_t *data, uint8_t nbytes){
     if(isI2Cbusy()) return 0;
diff --git a/F3:F303/NitrogenFlooding/indication.c b/F3:F303/NitrogenFlooding/indication.c
index e6bacf0..c61d0d3 100644
--- a/F3:F303/NitrogenFlooding/indication.c
+++ b/F3:F303/NitrogenFlooding/indication.c
@@ -18,9 +18,11 @@
 
 #include "BMP280.h"
 #include "buttons.h"
+#include "fonts.h"
 #include "hardware.h"
 #include "ili9341.h"
-#include "incication.h"
+#include "indication.h"
+#include "menu.h"
 #include "screen.h"
 #include "strfunc.h"
 #include "usb.h"
@@ -38,6 +40,23 @@ static uint32_t ledT[LEDS_AMOUNT] = {0};
 static uint32_t ledH[LEDS_AMOUNT] = {199, 0, 0, 0};
 static uint32_t ledL[LEDS_AMOUNT] = {799, 1, 1, 1};
 
+static void refresh_mainwin(uint8_t evtmask);
+static void refresh_menu(uint8_t evtmask);
+
+// current menu
+static menu *curmenu = &mainmenu;
+// window handler
+window_handler swhandler = refresh_mainwin;
+
+// Display state: window or menu
+typedef enum{
+    DISP_WINDOW,    // show window
+    DISP_MENU       // show menu
+} display_state;
+
+static display_state dispstate = DISP_WINDOW;
+static uint32_t lastTupd = 0; // last main window update time
+
 // led blinking
 TRUE_INLINE void leds_proc(){
     uint32_t v = getPWM(2);
@@ -62,61 +81,43 @@ TRUE_INLINE void leds_proc(){
     }
 }
 
-// Display state: main window or menu
-typedef enum{
-    DISP_MAINWIN,
-    DISP_MENU
-} display_state;
-
-static display_state dispstate = DISP_MAINWIN;
-static uint32_t lastTmeas = 0; // last measurement time
-
-static void cls(){ // set default colors (bg=0, fg=0xffff) and clear screen
-    setBGcolor(0);
-    setFGcolor(0xffff);
-    ClearScreen();
-}
-
-static void refresh_mainwin(){ // ask all parameters and refresh main window with new values
-    DBG("REFRESH main window");
+static void refresh_mainwin(uint8_t evtmask){ // ask all parameters and refresh main window with new values
+    if(evtmask & BTN_ESC_MASK){ // force refresh
+        Sens_measured_time = Tms - SENSORS_DATA_TIMEOUT*2; // force refresh
+        lastTupd = Tms;
+        return; // just start measurements
+    }
+    if(evtmask & BTN_SEL_MASK){ // switch to menu
+        init_menu(&mainmenu);
+        return;
+    }
+    if(evtmask) return; // left/right buttons - do nothing
     cls();
-    float T, P, H;
-    BMP280_status s = BMP280_get_status();
-    if(s == BMP280_NOTINIT || s == BMP280_ERR) BMP280_init();
     SetFontScale(1); // small menu items labels
     setBGcolor(COLOR_BLACK); setFGcolor(COLOR_LIGHTGREEN);
     PutStringAt(4, 16, "Temperature Pressure Humidity Dew point");
     int y = 37;
     uint16_t fgcolor;
-    if(s == BMP280_RDY && BMP280_getdata(&T, &P, &H)){ // show data
-        if(T < T_MIN || T > T_MAX) fgcolor = COLOR_RED;
-        else if(T < 0) fgcolor = COLOR_BLUE;
+    if(Tms - Sens_measured_time < 2*SENSORS_DATA_TIMEOUT){ // data was recently refreshed
+        if(Temperature < T_MIN || Temperature > T_MAX) fgcolor = COLOR_RED;
+        else if(Temperature < 0) fgcolor = COLOR_BLUE;
         else fgcolor = COLOR_GREEN;
-        setFGcolor(fgcolor); PutStringAt(32, y, float2str(T, 2));
-        if(P > P_MAX) fgcolor = COLOR_RED;
+        setFGcolor(fgcolor); PutStringAt(32, y, float2str(Temperature, 2));
+        if(Pressure > P_MAX) fgcolor = COLOR_RED;
         else fgcolor = COLOR_YELLOW;
-        setFGcolor(fgcolor); PutStringAt(112, y, float2str(P, 1));
-        if(H > H_MAX) fgcolor = COLOR_RED;
+        setFGcolor(fgcolor); PutStringAt(104, y, float2str(Pressure, 1));
+        if(Humidity > H_MAX) fgcolor = COLOR_RED;
         else fgcolor = COLOR_CHOCOLATE;
-        setFGcolor(fgcolor); PutStringAt(192, y, float2str(H, 1));
-        float dew = Tdew(T, H);
-        if(T - dew < DEW_MIN) fgcolor = COLOR_RED;
+        setFGcolor(fgcolor); PutStringAt(184, y, float2str(Humidity, 1));
+        if(Temperature - Dewpoint < DEW_MIN) fgcolor = COLOR_RED;
         else fgcolor = COLOR_LIGHTBLUE;
-        setFGcolor(fgcolor); PutStringAt(248, y, float2str(dew, 1));
-#ifdef EBUG
-        USB_sendstr("T="); USB_sendstr(float2str(T, 2)); USB_sendstr("\nP=");
-        USB_sendstr(float2str(P, 1));
-        P *= 0.00750062f; USB_sendstr("\nPmm="); USB_sendstr(float2str(P, 1));
-        USB_sendstr("\nH="); USB_sendstr(float2str(H, 1));
-        USB_sendstr("\nTdew="); USB_sendstr(float2str(dew, 1));
-        newline();
-#endif
+        setFGcolor(fgcolor); PutStringAt(248, y, float2str(Dewpoint, 1));
     }else{ // show "errr"
         setBGcolor(COLOR_RED); setFGcolor(COLOR_CYAN);
         CenterStringAt(y, "No signal");
     }
     // display all other data
-    SetFontScale(3);
+    SetFontScale(3); setBGcolor(COLOR_BLACK);
     // TODO: show current level
     setFGcolor(COLOR_RED); CenterStringAt(130, "Level: NULL");
     if(getPWM(2) || getPWM(3)){
@@ -124,12 +125,70 @@ static void refresh_mainwin(){ // ask all parameters and refresh main window wit
         CenterStringAt(220, "Processing");
     }
     UpdateScreen(0, SCRNH-1);
-    if(!BMP280_start()) BMP280_init(); // start new measurement
 }
 
-static void refresh_menu(){ // refresh menu with changed selection
+#define refresh_window(e)   swhandler(e)
+
+void init_window(window_handler h){
+    dispstate = DISP_WINDOW;
+    swhandler = h ? h : refresh_mainwin;
+    refresh_window(0);
+}
+
+void init_menu(menu *m){
+    dispstate = DISP_MENU;
+    curmenu = m;
+    refresh_menu(0);
+}
+
+static void refresh_menu(uint8_t evtmask){ // refresh menu with changed selection
     DBG("REFRESH menu");
+    if(!curmenu){
+        init_window(refresh_mainwin);
+        return;
+    }
+    if(evtmask & BTN_ESC_MASK){ // escape to level upper or to main window
+        if(curmenu) curmenu = curmenu->parent;
+        if(!curmenu){
+            init_window(refresh_mainwin);
+            return;
+        }
+    } else if(evtmask & BTN_SEL_MASK){
+        menuitem *selitem = &curmenu->items[curmenu->selected];
+        menu *sub = selitem->submenu;
+        void (*action)() = selitem->action;
+        if(action) action(curmenu);
+        if(sub){ // change to submenu
+            curmenu = sub;
+        } else return;
+    } else if(evtmask & BTN_LEFT_MASK){ // up
+        if(curmenu->selected) --curmenu->selected;
+    } else if(evtmask & BTN_RIGHT_MASK){ // down
+        if(curmenu->selected < curmenu->nitems - 1) ++curmenu->selected;
+    }
     cls();
+    // check number of first menu item to display
+    int firstitem = 0, nitemsonscreen = SCRNH / fontheight, half = nitemsonscreen/2;
+    if(curmenu->nitems > nitemsonscreen){ // menu is too large
+        if(curmenu->nitems - curmenu->selected <= half) firstitem = curmenu->nitems - nitemsonscreen;
+        else firstitem = curmenu->selected - half;
+    } else nitemsonscreen = curmenu->nitems;
+    if(firstitem < 0) firstitem = 0;
+    SetFontScale(3);
+    int Y = fontheight - fontbase + 1;
+    for(int i = 0; i < nitemsonscreen; ++i, Y += fontheight){
+        int idx = firstitem + i;
+        if(idx >= curmenu->nitems) break;
+        if(idx == curmenu->selected){ // invert fg/bg
+            setFGcolor(COLOR_BLACK);
+            setBGcolor(COLOR_DARKGREEN);
+        }else{
+            setFGcolor(COLOR_DARKGREEN);
+            setBGcolor(COLOR_BLACK);
+        }
+        CenterStringAt(Y, curmenu->items[idx].text);
+    }
+    UpdateScreen(0, SCRNH-1);
 }
 
 /*
@@ -139,50 +198,33 @@ static void refresh_menu(){ // refresh menu with changed selection
  * 2 - down
  * 3 - select/menu
  */
-TRUE_INLINE void btns_proc(){
+TRUE_INLINE uint8_t btns_proc(){
+    static uint32_t lastT = 0;
     uint8_t evtmask = 0; // bitmask for active buttons (==1)
+    static keyevent lastevent[BTNSNO] = {0};
+    if(lastUnsleep == lastT) return 0; // no buttons activity
+    lastT = lastUnsleep;
     for(int i = 0; i < BTNSNO; ++i){
         keyevent evt = keystate(i, NULL); // T may be used for doubleclick detection
-        if(evt == EVT_PRESS || evt == EVT_HOLD) evtmask |= 1<<i;
-    }
-    // now check all buttons
-    if(evtmask & 1<<0){ // escape to main window or force refresh
-        if(dispstate == DISP_MENU){
-            dispstate = DISP_MAINWIN;
-        }
-        lastTmeas = Tms - SENSORS_DATA_TIMEOUT*2; // force refresh
-    }
-    if(dispstate == DISP_MENU){ // buttons 'up'/'down' works only in menu mode
-        if(evtmask & 1<<1){ // up
-            ;
-        }
-        if(evtmask & 1<<2){ // down
-            ;
-        }
-    }
-    if(evtmask & 1<<3){ // select/menu
-        if(dispstate == DISP_MAINWIN){ // switch to menu mode
-            dispstate = DISP_MENU;
-            refresh_menu();
-        }else{ // select
-            ;
-        }
+        if(evt == EVT_PRESS && lastevent[i] != EVT_PRESS) evtmask |= 1<<i;
+        lastevent[i] = evt;
     }
+    if(!evtmask) return 0;
+    if(dispstate == DISP_WINDOW) refresh_window(evtmask);
+    else refresh_menu(evtmask);
+    return evtmask;
 }
 
 void indication_process(){
     if(!LEDsON) return;
     leds_proc();
-    btns_proc();
-    switch(dispstate){
-        case DISP_MAINWIN:
-            if(Tms - lastTmeas > SENSORS_DATA_TIMEOUT){
-                refresh_mainwin();
-                lastTmeas = Tms;
-            }
-        break;
-        case DISP_MENU: // do nothing
-            ;
-        break;
+    if(ScrnState != SCREEN_RELAX) return; // dont process buttons when screen in updating state
+    uint8_t e = btns_proc();
+    if(dispstate == DISP_WINDOW){ // send refresh by timeout event
+        if(e) lastTupd = Tms;
+        else if(Tms - lastTupd > WINDOW_REFRESH_TIMEOUT){
+            lastTupd = Tms;
+            refresh_window(0);
+        }
     }
 }
diff --git a/F3:F303/NitrogenFlooding/incication.h b/F3:F303/NitrogenFlooding/indication.h
similarity index 93%
rename from F3:F303/NitrogenFlooding/incication.h
rename to F3:F303/NitrogenFlooding/indication.h
index afbf7a2..61bf5fa 100644
--- a/F3:F303/NitrogenFlooding/incication.h
+++ b/F3:F303/NitrogenFlooding/indication.h
@@ -18,6 +18,8 @@
 
 #pragma once
 
+#include "menu.h"
+
 // temporary defines - should be stored in settings
 // temperature (degC) limits
 #define T_MIN       (-20.f)
@@ -30,3 +32,5 @@
 #define DEW_MIN     (3.f)
 
 void indication_process();
+void init_window(window_handler h);
+void init_menu(menu *m);
diff --git a/F3:F303/NitrogenFlooding/main.c b/F3:F303/NitrogenFlooding/main.c
index 0dd74f7..c220c86 100644
--- a/F3:F303/NitrogenFlooding/main.c
+++ b/F3:F303/NitrogenFlooding/main.c
@@ -24,7 +24,7 @@
 #include "hardware.h"
 #include "i2c.h"
 #include "ili9341.h"
-#include "incication.h"
+#include "indication.h"
 #include "proto.h"
 #include "screen.h"
 #include "strfunc.h"
@@ -33,11 +33,43 @@
 #define MAXSTRLEN    RBINSZ
 
 volatile uint32_t Tms = 0;
-
 void sys_tick_handler(void){
     ++Tms;
 }
 
+// global BME data and last measured time
+float Temperature, Pressure, Humidity, Dewpoint;
+uint32_t Sens_measured_time = 100000;
+uint16_t ADCvals[NUMBER_OF_ADC_CHANNELS]; // raw ADC values
+
+// get BME and sensors data for different calculations
+static void getsensors(){
+    // turn ON ADC voltage
+    ADCON(1);
+    BMP280_status s = BMP280_get_status();
+    if(s == BMP280_NOTINIT || s == BMP280_ERR) BMP280_init();
+    else if(s == BMP280_RDY && BMP280_getdata(&Temperature, &Pressure, &Humidity)){
+        Dewpoint = Tdew(Temperature, Humidity);
+#if 0
+        USB_sendstr("T="); USB_sendstr(float2str(Temperature, 2)); USB_sendstr("\nP=");
+        USB_sendstr(float2str(Pressure, 1));
+        USB_sendstr("\nPmm="); USB_sendstr(float2str(Pressure * 0.00750062f, 1));
+        USB_sendstr("\nH="); USB_sendstr(float2str(Humidity, 1));
+        USB_sendstr("\nTdew="); USB_sendstr(float2str(Dewpoint, 1));
+        newline();
+#endif
+    }
+    // here we should collect and process ADC data - get level etc
+    for(uint32_t i = 0; i < NUMBER_OF_ADC_CHANNELS; ++i){
+        ADCvals[i] = getADCval(i);
+#if 0
+        USB_sendstr("ADC"); USB_sendstr(u2str(i)); USB_putbyte('=');
+        USB_sendstr(u2str(ADCvals[i])); newline();
+#endif
+    }
+    ADCON(0); // and turn off ADC
+    if(!BMP280_start()){ BMP280_init(); BMP280_start(); }
+}
 
 // SPI setup done in `screen.h`
 int main(void){
@@ -55,10 +87,15 @@ int main(void){
     //CAN_setup(the_conf.CANspeed);
     adc_setup();
     BMP280_setup(0);
+    BMP280_start();
     USBPU_ON();
     // CAN_message *can_mesg;
     while(1){
         IWDG->KR = IWDG_REFRESH;
+        if(Tms - Sens_measured_time > SENSORS_DATA_TIMEOUT){ // get BME
+            getsensors();
+            Sens_measured_time = Tms;
+        }
         /*CAN_proc();
         if(CAN_get_status() == CAN_FIFO_OVERRUN){
             USB_sendstr("CAN bus fifo overrun occured!\n");
@@ -105,7 +142,9 @@ int main(void){
                 LEDS_OFF();
                 ili9341_off();
             }else{ // check operation buttons for menu etc
+                IWDG->KR = IWDG_REFRESH;
                 indication_process();
+                IWDG->KR = IWDG_REFRESH;
             }
         }else{
             if(Tms - lastUnsleep < BTN_ACTIVITY_TIMEOUT/2){ // recent activity - turn on indication
diff --git a/F3:F303/NitrogenFlooding/menu.c b/F3:F303/NitrogenFlooding/menu.c
new file mode 100644
index 0000000..0165415
--- /dev/null
+++ b/F3:F303/NitrogenFlooding/menu.c
@@ -0,0 +1,167 @@
+/*
+ * This file is part of the nitrogen project.
+ * Copyright 2023 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "adc.h"
+#include "hardware.h"
+#include "indication.h"
+#include "menu.h"
+#include "screen.h"
+#include "strfunc.h"
+#include "usb.h"
+
+// integer parameter to change
+typedef struct{
+    uint32_t min;
+    uint32_t max;
+    uint32_t cur;
+    uint32_t *val;
+} u32par;
+
+// current parameter of uint32_t setter
+static u32par u32parameter = {0};
+
+static const char *parname = NULL;
+
+// upper level menu to return from subwindow functions
+static menu *uplevel = NULL;
+
+static void showadc(menu *m);
+static void htr1(menu *m);
+static void htr2(menu *m);
+
+static void testx(const char *text){
+    USB_sendstr(text);
+    USB_sendstr(" pressed\n");
+}
+
+static void test3(menu _U_ *m){testx("main 3");}
+static void test4(menu _U_ *m){testx("main 4");}
+static void stest1(menu _U_ *m){testx("sub 1");}
+static void stest2(menu _U_ *m){testx("sub 2");}
+static void stest3(menu _U_ *m){testx("sub 3");}
+static void stest4(menu _U_ *m){testx("sub 4");}
+static void stest5(menu _U_ *m){testx("sub 5");}
+
+
+static menuitem submenu1items[] = {
+    {"test 1", NULL, stest1},
+    {"test 2", NULL, stest2},
+    {"test 3", NULL, stest3},
+    {"test 4", NULL, stest4},
+    {"test 5", NULL, stest5},
+};
+
+static menu submenu1 = {
+    .parent = &mainmenu,
+    .nitems = 5,
+    .selected = 0,
+    .items = submenu1items
+};
+
+static menuitem mainmenuitems[] = {
+    {"ADC raw data", NULL, showadc},
+    {"Heater1 power", NULL, htr1},
+    {"Heater2 power", NULL, htr2},
+    {"Submenu1", &submenu1, NULL},
+    {"Test3", NULL, test3},
+    {"Test4", NULL, test4},
+};
+
+menu mainmenu = {
+    .parent = NULL,
+    .nitems = 6,
+    .selected = 0,
+    .items = mainmenuitems
+};
+
+static void refresh_adcwin(uint8_t evtmask){
+    if(evtmask & BTN_ESC_MASK || evtmask & BTN_SEL_MASK){ // switch to menu
+        init_menu(uplevel);
+        return;
+    }
+    if(evtmask) return;
+    cls();
+    SetFontScale(1);
+    int Y = fontheight + 1, wmax = 0;
+    setFGcolor(COLOR_CYAN);
+    for(int i = 0; i < NUMBER_OF_AIN_CHANNELS; ++i, Y+=fontheight+2){
+        int X = 20;
+        X = PutStringAt(X, Y, "ADC input ");
+        X = PutStringAt(X, Y, u2str(i));
+        if(X > wmax) wmax = X;
+    }
+    wmax += 20;
+    setFGcolor(COLOR_WHITE);
+    Y = fontheight + 1;
+    for(int i = 0; i < NUMBER_OF_AIN_CHANNELS; ++i, Y+=fontheight+2){
+        PutStringAt(wmax, Y, u2str(ADCvals[i]));
+    }
+    setFGcolor(COLOR_LIGHTGREEN);
+    Y += 5;
+    PutStringAt(20, Y, "ADC ext"); PutStringAt(wmax, Y, u2str(ADCvals[ADC_EXT]));
+    //setFGcolor(COLOR_LIGHTYELLOW);
+    //Y += 2 + fontheight;
+    //PutStringAt(20, Y, "T MCU"); PutStringAt(wmax, Y, float2str(getMCUtemp(), 0));
+    UpdateScreen(0, -1);
+}
+
+// show RAW ADC data
+static void showadc(menu *m){
+    init_window(refresh_adcwin);
+    uplevel = m;
+}
+
+// window of uint32_t setter
+static void refresh_u32setter(uint8_t evtmask){
+    int selected = 0;
+    if(evtmask & BTN_ESC_MASK){ // return to main menu
+        init_menu(uplevel);
+        return;
+    }
+    cls();
+    if(evtmask & BTN_SEL_MASK){ // change value
+        *u32parameter.val = u32parameter.cur;
+        selected = 1;
+    } else if(evtmask & BTN_LEFT_MASK){ // decrement
+        if(u32parameter.cur > u32parameter.min) --u32parameter.cur;
+    } else if(evtmask & BTN_RIGHT_MASK){ // increment
+        if(u32parameter.cur < u32parameter.max) ++u32parameter.cur;
+    }
+    setFGcolor(COLOR_CHOCOLATE);
+    SetFontScale(2);
+    int Y = fontheight + fontheight/2;
+    CenterStringAt(Y, parname);
+    SetFontScale(3);
+    Y += fontheight + fontheight/2;
+    if(selected) setFGcolor(COLOR_GREEN);
+    else setFGcolor(COLOR_BLUE);
+    CenterStringAt(Y, u2str(u32parameter.cur));
+}
+
+// init pwm setter
+static void showpwm(menu *m, int nccr){
+    u32parameter.max = 100;
+    u32parameter.min = 0;
+    u32parameter.cur = (nccr == 3) ? TIM3->CCR3 : TIM3->CCR4;
+    u32parameter.val = (nccr == 3) ? (uint32_t*) &TIM3->CCR3 : (uint32_t*) &TIM3->CCR4;
+    parname = m->items[m->selected].text;
+    uplevel = m;
+    init_window(refresh_u32setter);
+}
+static void htr1(menu *m){showpwm(m, 3);}
+static void htr2(menu *m){showpwm(m, 4);}
diff --git a/F3:F303/NitrogenFlooding/menu.h b/F3:F303/NitrogenFlooding/menu.h
new file mode 100644
index 0000000..6596fde
--- /dev/null
+++ b/F3:F303/NitrogenFlooding/menu.h
@@ -0,0 +1,40 @@
+/*
+ * This file is part of the nitrogen project.
+ * Copyright 2023 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <stdint.h>
+
+struct _menu_;
+typedef struct{
+    const char *text;                   // name of menu item
+    struct _menu_ *submenu;             // submenu if selected
+    void (*action)(struct _menu_ *top); // action when item selected (be carefull when both `submenu` and `action` !=NULL), top - parent menu
+} menuitem;
+
+typedef struct _menu_{
+    struct _menu_ *parent;  // parent menu (when `ESC` pressed) or NULL if should return to main window
+    int nitems;             // amount of `menuitem`
+    int selected;           // selected item
+    menuitem *items;        // array of `menuitem` - menu itself
+} menu;
+
+extern menu mainmenu;
+
+// subwindow handler
+typedef void (*window_handler)(uint8_t evtmask);
diff --git a/F3:F303/NitrogenFlooding/nitrogen.bin b/F3:F303/NitrogenFlooding/nitrogen.bin
index 61c4c13..c64dc54 100755
Binary files a/F3:F303/NitrogenFlooding/nitrogen.bin and b/F3:F303/NitrogenFlooding/nitrogen.bin differ
diff --git a/F3:F303/NitrogenFlooding/nitrogen.files b/F3:F303/NitrogenFlooding/nitrogen.files
index 5b5717e..79bd216 100644
--- a/F3:F303/NitrogenFlooding/nitrogen.files
+++ b/F3:F303/NitrogenFlooding/nitrogen.files
@@ -24,9 +24,11 @@ i2c.c
 i2c.h
 ili9341.c
 ili9341.h
-incication.h
 indication.c
+indication.h
 main.c
+menu.c
+menu.h
 pdnuart.c
 pdnuart.h
 proto.c
diff --git a/F3:F303/NitrogenFlooding/proto.c b/F3:F303/NitrogenFlooding/proto.c
index 542a505..9b8532d 100644
--- a/F3:F303/NitrogenFlooding/proto.c
+++ b/F3:F303/NitrogenFlooding/proto.c
@@ -366,7 +366,7 @@ static int sputstr(const char _U_ *cmd, int parno, const char *c, int32_t _U_ i)
 }
 static int sstate(const char _U_ *cmd, int _U_ parno, const char _U_ *c, int32_t _U_ i){
     const char *s = "unknown";
-    switch(getScreenState()){
+    switch(ScrnState){
         case SCREEN_INIT:
             s = "init";
         break;
diff --git a/F3:F303/NitrogenFlooding/screen.c b/F3:F303/NitrogenFlooding/screen.c
index 63dcb40..4236c54 100644
--- a/F3:F303/NitrogenFlooding/screen.c
+++ b/F3:F303/NitrogenFlooding/screen.c
@@ -28,6 +28,8 @@
 #include "strfunc.h"
 #endif
 
+#include <string.h>
+
 #define SWAPINT(a,b) do{register int r = a; a = b; b = r;}while(0)
 
 // sprites 8x8 bytes with 8bit foreground and 8bit background
@@ -57,25 +59,23 @@ static int updidx = 0; // ==-1 to initialize update
 // next data portion size (in bytes!), total amount of bytes in update buffer
 static int portionsz = 0, updbuffsz;
 // font scale
-static uint8_t fontscale = 1;
+uint8_t fontscale = 1;
+int fontheight = 0, fontbase = 0;
 
 static uint16_t fgColor = 0xff, bgColor = 0; // foreground and background colors
 void setBGcolor(uint16_t c){bgColor = c;}
 void setFGcolor(uint16_t c){fgColor = c;}
 
-static screen_state ScrnState = SCREEN_INIT;
-screen_state getScreenState(){return ScrnState;}
+screen_state ScrnState = SCREEN_INIT;
 
 /**
  * @brief UpdateScreen - request to screen updating from lines y0 to y1 (including)
  * @param y0, y1 - first and last line of field to update
  */
 void UpdateScreen(int y0, int y1){
-    if(y0 > y1) SWAPINT(y0, y1);
+    //if(y0 > y1) SWAPINT(y0, y1);
     if(y0 < 0) y0 = 0;
-    if(y1 > SCRNH) y1 = SCRNH - 1;
-   //USB_sendstr("y0="); USB_sendstr(i2str(y0)); newline();
-   //USB_sendstr("y1="); USB_sendstr(i2str(y1)); newline();
+    if(y1 > SCRNH || y1 < 0) y1 = SCRNH - 1;
     uy0 = y0; uy1 = y1;
     updidx = -1;
     updbuffsz = SCRNW * (1 + y1 - y0);
@@ -93,20 +93,23 @@ void ClearScreen(){
     UpdateScreen(0, SCRNH-1);
 }
 
+#define DRAWPIX(X, Y, pix) \
+    if((X) > -1 && (X) < SCRNW && (Y) > -1 && (Y) < SCRNH){ \
+        int16_t spritex = (X)/SPRITEWD, spriteidx = spritex + SCRNSPRITEW * ((Y) / SPRITEHT); \
+        uint8_t *ptr = &screenbuf[(Y)*SCRNSPRITEW + spritex]; \
+        if(pix) *ptr |= 1 << (7 - ((X)%8)); \
+        else *ptr &= ~(1 << (7 - ((X)%8))); \
+        foreground[spriteidx] = fgColor; \
+        background[spriteidx] = bgColor; \
+    }
+
 /**
  * @brief DrawPix - set or clear pixel
  * @param X, Y - pixel coordinates (could be outside of screen)
  * @param pix - 1 - foreground, 0 - background
  */
 void DrawPix(int X, int Y, uint8_t pix){
-    if(X < 0 || X > SCRNW-1 || Y < 0 || Y > SCRNH-1) return; // outside of screen
-    // now calculate coordinate of pixel
-    int16_t spritex = X/SPRITEWD, spriteidx = spritex + SCRNSPRITEW * (Y / SPRITEHT);
-    uint8_t *ptr = &screenbuf[Y*SCRNSPRITEW + spritex]; // pointer to byte with 8 pixels
-    if(pix) *ptr |= 1 << (7 - (X%8));
-    else *ptr &= ~(1 << (7 - (X%8)));
-    foreground[spriteidx] = fgColor;
-    background[spriteidx] = bgColor;
+    DRAWPIX(X, Y, pix);
 }
 
 /**
@@ -135,9 +138,15 @@ void invertSpriteColor(int xmin, int xmax, int ymin, int ymax){
 
 uint8_t SetFontScale(uint8_t scale){
     if(scale > 0 && scale <= FONTSCALEMAX) fontscale = scale;
+    fontheight = curfont->height * fontscale;
+    fontbase = curfont->baseline * fontscale;
     return fontscale;
 }
 
+// left and right bits clearing masks
+//static const uint8_t lmask[8] = {0xff, 0b01111111, 0b00111111, 0b00011111, 0b00001111, 0b00000111, 0b00000011, 0b00000001};
+//static const uint8_t rmask[8] = {0, 0b10000000, 0b11000000, 0b11100000, 0b11110000, 0b11111000, 0b11111100, 0b11111110};
+
 // TODO in case of low speed: draw at once full line?
 /**
  * @brief DrawCharAt - draws character @ position X,Y (this point is left baseline corner of char!)
@@ -150,7 +159,7 @@ uint8_t DrawCharAt(int X, int Y, uint8_t Char){
     const uint8_t *curchar = font_char(Char);
     if(!curchar) return 0;
     // now change Y coordinate to left upper corner of font
-    Y += fontscale*(curfont->baseline - curfont->height + 1);
+    Y += fontbase - fontheight + 1;
     // height and width of letter in pixels
     uint8_t h = curfont->height, w = *curchar++; // now curchar is pointer to bits array
     uint8_t lw = curfont->bytes / h; // width of letter in bytes
@@ -159,8 +168,10 @@ uint8_t DrawCharAt(int X, int Y, uint8_t Char){
         for(uint8_t col = 0; col < w; ++col){
             register uint8_t pix = curchar[row*lw + (col/8)] & (1 << (7 - (col%8)));
             int xx = X + fontscale * col;
-            for(int y = 0; y < fontscale; ++y) for(int x = 0; x < fontscale; ++x)
-                DrawPix(xx + x, Y1 + y, pix);
+            for(int y = 0; y < fontscale; ++y) for(int x = 0; x < fontscale; ++x){
+                int nxtx = xx+x, nxty = Y1+y;
+                DRAWPIX(nxtx, nxty, pix);
+            }
         }
     }
     return w * fontscale;
@@ -193,6 +204,7 @@ int CenterStringAt(int Y, const char *str){
 
 // full string length in pixels
 int strpixlen(const char *str){
+    if(!str) return 0;
     int l = 0;
     while(*str){
         const uint8_t *c = font_char(*str++);
@@ -251,6 +263,8 @@ void process_screen(){
         case SCREEN_INIT: // try to init SPI and screen
             DBG("SCREEN_INIT");
             spi_setup();
+            choose_font(FONT14);
+            SetFontScale(1);
             if(ili9341_init()) ScrnState = SCREEN_RELAX;
             else{
                 Tscr_last = Tms;
@@ -262,7 +276,7 @@ void process_screen(){
         break;
         case SCREEN_RELAX: // check need of updating
             if(updidx > -1) return;
-            DBG("Need to update");
+            //DBG("Need to update");
             if(!ili9341_setcol(0, SCRNW-1)) return;
             if(!ili9341_setrow(uy0, uy1)) return;
             if(!ili9341_writecmd(ILI9341_RAMWR)) return;
diff --git a/F3:F303/NitrogenFlooding/screen.h b/F3:F303/NitrogenFlooding/screen.h
index fd2e567..ba1a71f 100644
--- a/F3:F303/NitrogenFlooding/screen.h
+++ b/F3:F303/NitrogenFlooding/screen.h
@@ -19,6 +19,7 @@
 #pragma once
 
 #include <stdint.h>
+#include <stm32f3.h>
 
 typedef enum{ // screen states
      SCREEN_INIT        // init stage
@@ -88,7 +89,9 @@ typedef enum{ // screen states
 #define COLOR_YELLOWGREEN 0x9E66
 
 
-screen_state getScreenState();
+extern screen_state ScrnState;
+extern int fontheight, fontbase;
+
 void ClearScreen();
 void UpdateScreen(int y0, int y1);
 void setBGcolor(uint16_t c);
@@ -103,3 +106,8 @@ int strpixlen(const char *str);
 uint8_t *getScreenBuf();
 void process_screen();
 
+TRUE_INLINE void cls(){ // set default colors (bg=0, fg=0xffff) and clear screen
+    setBGcolor(0);
+    setFGcolor(0xffff);
+    ClearScreen();
+}
diff --git a/F3:F303/NitrogenFlooding/version.inc b/F3:F303/NitrogenFlooding/version.inc
index f64e00a..fdeef24 100644
--- a/F3:F303/NitrogenFlooding/version.inc
+++ b/F3:F303/NitrogenFlooding/version.inc
@@ -1,2 +1,2 @@
-#define BUILD_NUMBER "253"
-#define BUILD_DATE "2023-05-12"
+#define BUILD_NUMBER "280"
+#define BUILD_DATE "2023-05-14"