diff --git a/F3:F303/BME280/BMP280.c b/F3:F303/BME280/BMP280.c
index a1bd6ba..bad50a7 100644
--- a/F3:F303/BME280/BMP280.c
+++ b/F3:F303/BME280/BMP280.c
@@ -42,16 +42,18 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "hardware.h"
 #include "i2c.h"
 #include "spi.h"
 #include "BMP280.h"
 
+#include "usb_dev.h" // DBG
 #ifdef EBUG
 #include "strfunc.h"
-#include "usb_dev.h"
 extern volatile uint32_t Tms;
 #endif
 
+#include <string.h>
 #include <math.h>
 
 #define BMP280_I2C_ADDRESS_MASK (0x76)
@@ -87,6 +89,8 @@ extern volatile uint32_t Tms;
 
 #define BMP280_MODE_FORSED      (1)  // force single measurement
 #define BMP280_MODE_NORMAL      (3)  // run continuosly
+#define BMP280_STATUS_IMCOPY    (1<<0) // im-copy (sensor busy)
+#define BME280_STATUS_MSRGOOD   (1<<2) // measurement is good (undocumented bit)
 #define BMP280_STATUS_MSRNG     (1<<3) // measuring in process
 
 static uint8_t curaddress = BMP280_I2C_ADDRESS_0<<1;
@@ -165,17 +169,27 @@ BMP280_status BMP280_get_status(){
 static uint8_t SPIbuf[SPI_BUFSIZE];
 
 // these functions for
-static uint8_t *spi_readregs(uint8_t address, uint8_t reg, uint8_t len){
+static uint8_t *spi_readregs(uint8_t _U_ address, uint8_t reg, uint8_t len){
     if(len > SPI_BUFSIZE-2) return NULL;
-    SPIbuf[0] = address | 0x80;
-    SPIbuf[1] = reg;
-    if(!spi_writeread(SPIbuf, len+2)) return NULL;
-    return SPIbuf + 2;
+    SPI_CS_0();
+    bzero(SPIbuf, sizeof(SPIbuf));
+    SPIbuf[0] = reg | 0x80;
+    int r = spi_writeread(SPIbuf, len+1);
+    SPI_CS_1();
+    if(!r) return NULL;
+#ifdef EBUG
+    USB_sendstr("Register "); USB_sendstr(uhex2str(reg)); USB_sendstr(": ");
+    hexdump(USB_sendstr, SPIbuf + 1, len);
+#endif
+    return SPIbuf + 1;
 }
-static uint8_t spi_write(uint8_t address, uint8_t *data, uint8_t n){
-    SPIbuf[0] = address;
-    memcpy(SPIbuf + 1, data, n);
-    return spi_writeread(SPIbuf, n+1);
+static uint8_t spi_write(uint8_t _U_ address, uint8_t *data, uint8_t n){
+    SPI_CS_0();
+    memcpy(SPIbuf, data, n);
+    SPIbuf[0] &= 0x7F; // clear MSbit
+    uint8_t r = spi_writeread(SPIbuf, n);
+    SPI_CS_1();
+    return r;
 }
 
 // address: 0 or 1
@@ -185,14 +199,13 @@ void BMP280_setup(uint8_t address, uint8_t isI2C){
         curaddress = (BMP280_I2C_ADDRESS_MASK | (address & 1))<<1;
         read_regs = i2c_read_regs;
         write_data = i2c_write;
-        i2c_setup(I2C_SPEED_10K);
+        i2c_setup(I2C_SPEED_400K);
     }else{
         curaddress = BMP280_I2C_ADDRESS_MASK | (address & 1);
         read_regs = spi_readregs;
         write_data = spi_write;
         spi_setup();
     }
-    BMP280_init();
 }
 
 // setters for `params`
@@ -233,43 +246,49 @@ static int readcompdata(){
 // read compensation data & write registers
 int BMP280_init(){
     IWDG->KR = IWDG_REFRESH;
-    DBG("INI:\n");
+    DBG("INI:");
     if(!read_reg(BMP280_REG_ID, &params.ID)){
-        DBG("Can't get ID\n");
+        DBG("Can't get ID");
         return 0;
     }
     if(params.ID != BMP280_CHIP_ID && params.ID != BME280_CHIP_ID){
-        DBG("Not BMP/BME\n");
+        DBG("Not BMP/BME");
         return 0;
     }
     if(!write_reg(BMP280_REG_RESET, BMP280_RESET_VALUE)){
-        DBG("Can't reset\n");
+        DBG("Can't reset");
         return 0;
     }
     uint8_t reg = 1;
-    while(reg & 1){
+    int ntries = 100;
+    while((reg & BMP280_STATUS_IMCOPY) && --ntries){
+        IWDG->KR = IWDG_REFRESH;
         if(!read_reg(BMP280_REG_STATUS, &reg)){
-            DBG("can't get status\n");
+            DBG("can't get status");
             return 0;
         }
     }
+    if(ntries < 0){
+        DBG("Timeout getting status");
+        return 0;
+    }
     if(!readcompdata()){
-        DBG("Can't read calibration data\n");
+        DBG("Can't read calibration data");
         return 0;
     }
     // write filter configuration
     reg = params.filter << 2;
-    if(!write_reg(BMP280_REG_CONFIG, reg)){DBG("Can't save filter settings\n");}
+    if(!write_reg(BMP280_REG_CONFIG, reg)){DBG("Can't save filter settings");}
     reg = (params.t_os << 5) | (params.p_os << 2); // oversampling for P/T, sleep mode
     if(!write_reg(BMP280_REG_CTRL, reg)){
-        DBG("Can't write settings for P/T\n");
+        DBG("Can't write settings for P/T");
         return 0;
     }
     params.regctl = reg;
     if(params.ID == BME280_CHIP_ID){ // write CTRL_HUM only AFTER CTRL!
         reg = params.h_os;
         if(!write_reg(BMP280_REG_CTRL_HUM, reg)){
-            DBG("Can't write settings for H\n");
+            DBG("Can't write settings for H");
             return 0;
         }
     }
@@ -296,7 +315,7 @@ int BMP280_start(){
     }
     uint8_t reg = params.regctl | BMP280_MODE_FORSED;
     if(!write_reg(BMP280_REG_CTRL, reg)){
-        DBG("Can't write CTRL reg\n");
+        DBG("Can't write CTRL reg");
         return 0;
     }
     bmpstatus = BMP280_BUSY;
@@ -311,7 +330,13 @@ void BMP280_process(){
     // BUSY state: poll data ready
     uint8_t reg;
     if(!read_reg(BMP280_REG_STATUS, &reg)) return;
-    if(reg & BMP280_STATUS_MSRNG) return; // still busy
+    if(reg & (BMP280_STATUS_MSRNG | BMP280_STATUS_IMCOPY)) return; // still busy
+   /* if(params.ID == BME280_CHIP_ID && !(reg & BME280_STATUS_MSRGOOD)){ // check if data is good
+        DBG("Wrong data!");
+        bmpstatus = BMP280_RELAX;
+        read_regs(curaddress, BMP280_REG_ALLDATA, 8);
+        return;
+    }*/
     bmpstatus = BMP280_RDY; // data ready
 }
 
@@ -382,8 +407,10 @@ int BMP280_getdata(float *T, float *P, float *H){
     int32_t p = (data[0] << 12) | (data[1] << 4) | (data[2] >> 4);
     int32_t t = (data[3] << 12) | (data[4] << 4) | (data[5] >> 4);
     int32_t t_fine;
-    int32_t Temp = compTemp(t, &t_fine);
-    if(T) *T = ((float)Temp)/100.f;
+    if(T){
+        int32_t Temp = compTemp(t, &t_fine);
+        *T = ((float)Temp)/100.f;
+    }
     if(P) *P = ((float)compPres(p, t_fine)) / 256.f;
     if(H){
         int32_t h = (data[6] << 8) | data[7];
@@ -394,6 +421,8 @@ int BMP280_getdata(float *T, float *P, float *H){
 
 // dewpoint calculation (T in degrC, H in percents)
 float Tdew(float T, float H){
+    if(H < 1e-3) return -300.f;
     float gamma = 17.27f * T / (237.7f + T) + logf(H/100.f);
-    return (237.7f * gamma)/(17.27 - gamma);
+    if(fabsf(17.27f - gamma) < 1e-3) return -300.f;
+    return (237.7f * gamma)/(17.27f - gamma);
 }
diff --git a/F3:F303/BME280/bme280.bin b/F3:F303/BME280/bme280.bin
index 20a2ef0..f05986b 100755
Binary files a/F3:F303/BME280/bme280.bin and b/F3:F303/BME280/bme280.bin differ
diff --git a/F3:F303/BME280/bme280.creator.user b/F3:F303/BME280/bme280.creator.user
index 9a72567..c00d1f5 100644
--- a/F3:F303/BME280/bme280.creator.user
+++ b/F3:F303/BME280/bme280.creator.user
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE QtCreatorProject>
-<!-- Written by QtCreator 17.0.1, 2025-10-02T21:41:30. -->
+<!-- Written by QtCreator 17.0.1, 2025-10-04T00:21:41. -->
 <qtcreator>
  <data>
   <variable>EnvironmentId</variable>
diff --git a/F3:F303/BME280/hardware.c b/F3:F303/BME280/hardware.c
index 3579757..f5a729c 100644
--- a/F3:F303/BME280/hardware.c
+++ b/F3:F303/BME280/hardware.c
@@ -24,8 +24,9 @@ static inline void gpio_setup(){
     // USB - alternate function 14 @ pins PA11/PA12; SWD - AF0 @PA13/14
     GPIOA->AFR[1] = AFRf(14, 11) | AFRf(14, 12);
     GPIOA->MODER = MODER_AF(11) | MODER_AF(12) | MODER_AF(13) | MODER_AF(14) | MODER_O(15);
-    GPIOB->MODER = MODER_O(0) | MODER_O(1);
-    GPIOB->ODR = 1;
+    GPIOB->MODER = MODER_O(0) | MODER_O(1) | MODER_O(2);
+    pin_set(GPIOB, 1<<1);
+    SPI_CS_1();
 }
 
 void hw_setup(){
diff --git a/F3:F303/BME280/hardware.h b/F3:F303/BME280/hardware.h
index fc241df..2b50da6 100644
--- a/F3:F303/BME280/hardware.h
+++ b/F3:F303/BME280/hardware.h
@@ -25,6 +25,10 @@
 #define USBPU_ON()  pin_clear(USBPU_port, USBPU_pin)
 #define USBPU_OFF() pin_set(USBPU_port, USBPU_pin)
 
+// SPI_CS - PB2 (pin 20)
+#define SPI_CS_1()      pin_set(GPIOB, 1<<2)
+#define SPI_CS_0()      pin_clear(GPIOB, 1<<2)
+
 extern volatile uint32_t Tms;
 
 void hw_setup();
diff --git a/F3:F303/BME280/main.c b/F3:F303/BME280/main.c
index 82b790e..c9a1374 100644
--- a/F3:F303/BME280/main.c
+++ b/F3:F303/BME280/main.c
@@ -43,7 +43,7 @@ int main(void){
     hw_setup();
     USBPU_OFF();
     USB_setup();
-    BMP280_setup(0, 1);
+    //BMP280_setup(0, 1);
     uint32_t ctr = Tms, Tmeas = 0;
     USBPU_ON();
     while(1){
@@ -57,20 +57,35 @@ int main(void){
             const char *ans = parse_cmd(inbuff);
             if(ans) USB_sendstr(ans);
         }
-        BMP280_process();
-        if(Tms - Tmeas > 9999){
-            BMP280_status s = BMP280_get_status();
-            float Temperature, Pressure, Humidity, Dewpoint;
-            if(s == BMP280_NOTINIT || s == BMP280_ERR) BMP280_init();
-            else if(s == BMP280_RDY && BMP280_getdata(&Temperature, &Pressure, &Humidity)){
-                Dewpoint = Tdew(Temperature, Humidity);
-                USB_sendstr("Tdeg="); USB_sendstr(float2str(Temperature, 2)); USB_sendstr("\nPpa=");
-                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();
-                Tmeas += 10000;
+        BMP280_status s = BMP280_get_status();
+        if(s != BMP280_NOTINIT){
+            if(s == BMP280_ERR) BMP280_init();
+            else{
+                BMP280_process();
+                s = BMP280_get_status(); // refresh status after processing
+                float Temperature, Pressure, Humidity, Dewpoint;
+                if(s == BMP280_RDY && BMP280_getdata(&Temperature, &Pressure, &Humidity)){
+                    Dewpoint = Tdew(Temperature, Humidity);
+                    USB_sendstr("Tdeg="); USB_sendstr(float2str(Temperature, 2)); USB_sendstr("\nPpa=");
+                    USB_sendstr(float2str(Pressure, 3));
+                    USB_sendstr("\nPmm="); USB_sendstr(float2str(Pressure * 0.00750062f, 2));
+                    USB_sendstr("\nH="); USB_sendstr(float2str(Humidity, 2));
+                    USB_sendstr("\nTdew="); USB_sendstr(float2str(Dewpoint, 1));
+                    newline();
+                }
+                if(contmeas && (Tms - Tmeas > 999)){
+                    if(BMP280_start()) Tmeas = Tms;
+                }
+            }
+        }
+        if(i2c_scanmode){
+            uint8_t addr;
+            int ok = i2c_scan_next_addr(&addr);
+            if(addr == I2C_ADDREND) USND("End scan");
+            else if(ok){
+                USB_sendstr(uhex2str(addr));
+                USB_sendstr(" ("); USB_sendstr(u2str(addr));
+                USB_sendstr(") - found device\n");
             }
         }
     }
diff --git a/F3:F303/BME280/proto.c b/F3:F303/BME280/proto.c
index bc4207a..5169c26 100644
--- a/F3:F303/BME280/proto.c
+++ b/F3:F303/BME280/proto.c
@@ -19,6 +19,8 @@
 #include <stm32f3.h>
 #include <string.h>
 
+#include "BMP280.h"
+#include "i2c.h"
 #include "spi.h"
 #include "strfunc.h"
 #include "usb_dev.h"
@@ -29,11 +31,19 @@
 static uint8_t locBuffer[LOCBUFFSZ];
 static const char *ERR = "ERR\n", *OK = "OK\n";
 extern volatile uint32_t Tms;
+int contmeas = 0; // continuous measurements each 1s
 
 const char *helpstring =
         "https://github.com/eddyem/stm32samples/tree/master/F3:F303/xxx build#" BUILD_NUMBER " @ " BUILD_DATE "\n"
-        "i - [re]init SPI1\n"
-        "s - send up to 32 bytes of data and read answer\n"
+        "c - set/reset continuous measurements\n"
+        "s - send up to 32 bytes of data over SPI and read answer\n"
+        "Axi - init BME280 with address x (0/1) and interface i (I/S - I2C/SPI)\n"
+        "Fx- set filter to x (0..4)\n"
+        "I - [re]init I2C\n"
+        "Is - scan I2C bus\n"
+        "M - start measurement\n"
+        "Ovx - set oversampling of v(t, h or p) to x(0..5)\n"
+        "S - [re]init SPI1\n"
         "T - print current Tms\n"
 ;
 
@@ -46,9 +56,9 @@ TRUE_INLINE uint16_t readNnumbers(const char *buf){
         if(D > 0xff){ USND("Each number should be uint8_t"); return 0; }
         buf = nxt;
         locBuffer[N++] = (uint8_t) D&0xff;
-        USND("add byte: "); USND(uhex2str(D&0xff)); USND("\n");
+        //USND("add byte: "); USND(uhex2str(D&0xff)); USND("\n");
     }
-    USND("Send "); USND(u2str(N)); USND(" bytes\n");
+    //USND("Send "); USND(u2str(N)); USND(" bytes\n");
     return N;
 }
 
@@ -62,23 +72,106 @@ TRUE_INLINE const char* spirdwr(const char *buf){
     return NULL;
 }
 
+TRUE_INLINE const char* bmeinint(const char *buf){
+    buf = omit_spaces(buf);
+    char c = *buf;
+    if(c != '0' && c != '1') return "Wrong address\n";
+    uint8_t addr = c - '0';
+    buf = omit_spaces(buf + 1);
+    c = *buf;
+    uint8_t isI2C = 0;
+    switch(c){
+        case 'i':
+        case 'I':
+            isI2C = 1;
+        case 's':
+        case 'S':
+        break;
+        default:
+            return "Wrong interface\n";
+    }
+    BMP280_setup(addr, isI2C);
+    if(BMP280_init()){
+        if(BMP280_read_ID(&addr)){
+            if(addr == BMP280_CHIP_ID) return "found BMP280\n";
+            else return "found BME280\n";
+        }else return "Failed read ID\n";
+    }
+    return ERR;
+}
+
+TRUE_INLINE const char* setos(const char *buf){
+    buf = omit_spaces(buf);
+    uint32_t U32;
+    void (*osfunc)(BMP280_Oversampling) = NULL;
+    switch(*buf){
+        case 'h': // h_os
+        case 'H':
+            osfunc = BMP280_setOSh;
+        break;
+        case 'p': // p_os
+        case 'P':
+            osfunc = BMP280_setOSp;
+        break;
+        case 't': // t_os
+        case 'T':
+            osfunc = BMP280_setOSt;
+        break;
+        default:
+            return "Wrong OS function\n";
+    }
+    buf = omit_spaces(buf+1);
+    if(!*buf) return "Need OS number\n";
+    if(buf != getnum(buf, &U32) && U32 < BMP280_OVERSMAX){
+        osfunc((BMP280_Oversampling)U32);
+        return OK;
+    }
+    return "Wrong OS number\n";
+}
+
 const char *parse_cmd(const char *buf){
+    uint32_t U32;
     // "long" commands
     if(buf[1]){
         char c = *buf++;
         switch(c){
             case 's':
                 return spirdwr(buf);
+            case 'A':
+                return bmeinint(buf);
+            case 'F':
+                buf = omit_spaces(buf);
+                if(buf != getnum(buf, &U32) && U32 < BMP280_FILTERMAX){
+                    BMP280_setfilter((BMP280_Filter)U32);
+                    return OK;
+                }else return ERR;
+            case 'I':
+                if(*buf == 's'){
+                    i2c_init_scan_mode();
+                    return "Start scan\n";
+                }else return ERR;
+            case 'O':
+                return setos(buf);
             default: return buf; // echo input
         }
     }
-  /*  switch(*buf){
-        case '':
-        break;
-    }*/
     // "short" commands
     switch(*buf){
-        case 'i':
+        case 'c':
+            contmeas = !contmeas;
+            if(contmeas){
+                if(BMP280_start()) return OK;
+                return ERR;
+            }
+            return OK;
+        case 'I':
+            i2c_setup(I2C_SPEED_400K);
+            return OK;
+        case 'M':
+            if(!BMP280_start()) return ERR;
+            else return OK;
+        break;
+        case 'S':
             spi_setup();
             return OK;
         case 'T':
diff --git a/F3:F303/BME280/proto.h b/F3:F303/BME280/proto.h
index 3ee30ab..d1d28b5 100644
--- a/F3:F303/BME280/proto.h
+++ b/F3:F303/BME280/proto.h
@@ -18,5 +18,6 @@
 
 #pragma once
 
+extern int contmeas;
 char *parse_cmd(char *buf);
 
diff --git a/F3:F303/BME280/spi.c b/F3:F303/BME280/spi.c
index 56fa8f8..3c99255 100644
--- a/F3:F303/BME280/spi.c
+++ b/F3:F303/BME280/spi.c
@@ -20,15 +20,15 @@
 #include "spi.h"
 #include <string.h> // memcpy
 
-#ifdef EBUG
 #include "usb_dev.h"
+#ifdef EBUG
 #include "strfunc.h"
 #endif
 
 spiStatus spi_status = SPI_NOTREADY;
 #define WAITX(x)  do{volatile uint32_t  wctr = 0; while((x) && (++wctr < 360000)) IWDG->KR = IWDG_REFRESH; if(wctr==360000){ DBG("timeout"); return 0;}}while(0)
 
-// init SPI
+// init SPI @ ~280kHz (36MHz/128)
 void spi_setup(){
     SPI1->CR1 = 0; // clear EN
     SPI1->CR2 = 0;
@@ -65,7 +65,7 @@ void spi_deinit(){
     spi_status = SPI_NOTREADY;
 }
 
-int spi_waitbsy(){
+uint8_t spi_waitbsy(){
     WAITX(SPI1->SR & SPI_SR_BSY);
     return 1;
 }
@@ -76,12 +76,13 @@ int spi_waitbsy(){
  * @param n - length of data
  * @return 0 if failed
  */
-int spi_writeread(uint8_t *data, uint8_t n){
+uint8_t spi_writeread(uint8_t *data, uint8_t n){
     if(spi_status != SPI_READY || !data || !n){
         DBG("not ready");
         return 0;
     }
     // clear SPI Rx FIFO
+    spi_onoff(TRUE);
     for(int i = 0; i < 4; ++i) (void) SPI1->DR;
     for(int x = 0; x < n; ++x){
         WAITX(!(SPI1->SR & SPI_SR_TXE));
@@ -89,11 +90,12 @@ int spi_writeread(uint8_t *data, uint8_t n){
         WAITX(!(SPI1->SR & SPI_SR_RXNE));
         data[x] = *((volatile uint8_t*)&SPI1->DR);
     }
+    spi_onoff(FALSE); // turn off SPI
     return 1;
 }
 
-// read data through SPI in read-only mode
-int spi_read(uint8_t *data, uint8_t n){
+// read data through SPI
+uint8_t spi_read(uint8_t *data, uint8_t n){
     if(spi_status != SPI_READY || !data || !n){
         DBG("not ready");
         return 0;
@@ -102,12 +104,10 @@ int spi_read(uint8_t *data, uint8_t n){
     for(int i = 0; i < 4; ++i) (void) SPI1->DR;
     spi_onoff(TRUE);
     for(int x = 0; x < n; ++x){
-        if(x == n - 1) SPI1->CR1 &= ~SPI_CR1_RXONLY; // clear RXonly bit to stop CLK generation after next byte
         WAITX(!(SPI1->SR & SPI_SR_RXNE));
         data[x] = *((volatile uint8_t*)&SPI1->DR);
     }
     spi_onoff(FALSE); // turn off SPI
-    SPI1->CR1 |= SPI_CR1_RXONLY; // and return RXonly bit
     return 1;
 }
 
diff --git a/F3:F303/BME280/spi.h b/F3:F303/BME280/spi.h
index 52e9f17..ecef67b 100644
--- a/F3:F303/BME280/spi.h
+++ b/F3:F303/BME280/spi.h
@@ -30,6 +30,6 @@ extern spiStatus spi_status;
 void spi_onoff(uint8_t on);
 void spi_deinit();
 void spi_setup();
-int spi_waitbsy();
-int spi_writeread(uint8_t *data, uint8_t n);
-int spi_read(uint8_t *data, uint8_t n);
+uint8_t spi_waitbsy();
+uint8_t spi_writeread(uint8_t *data, uint8_t n);
+uint8_t spi_read(uint8_t *data, uint8_t n);
diff --git a/F3:F303/BME280/usb_dev.h b/F3:F303/BME280/usb_dev.h
index b7bd929..605d34e 100644
--- a/F3:F303/BME280/usb_dev.h
+++ b/F3:F303/BME280/usb_dev.h
@@ -47,9 +47,9 @@ void linecoding_handler(usb_LineCoding *lc);
 #define RBINSZ      (1024)
 
 #ifdef EBUG
-#define DBG(x)  USB_sendstr(x)
+#define DBG(s)      do{USB_sendstr(s); USB_putbyte('\n');}while(0)
 #else
-#define DBG()
+#define DBG(s)
 #endif
 
 #define newline()   USB_putbyte('\n')
diff --git a/F3:F303/BME280/version.inc b/F3:F303/BME280/version.inc
index 691b49d..9d5676c 100644
--- a/F3:F303/BME280/version.inc
+++ b/F3:F303/BME280/version.inc
@@ -1,2 +1,2 @@
-#define BUILD_NUMBER "13"
-#define BUILD_DATE "2025-10-02"
+#define BUILD_NUMBER "33"
+#define BUILD_DATE "2025-10-04"