diff --git a/F3:F303/MLX90640-allsky/BMP280.c b/F3:F303/MLX90640-allsky/BMP280.c
new file mode 100644
index 0000000..374eebf
--- /dev/null
+++ b/F3:F303/MLX90640-allsky/BMP280.c
@@ -0,0 +1,399 @@
+/**
+ * Ciastkolog.pl (https://github.com/ciastkolog)
+ *
+*/
+/**
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2016 sheinz (https://github.com/sheinz)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+/*
+ * 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 "hardware.h"
+#include "spi.h"
+#include "BMP280.h"
+
+#include "usb_dev.h" // DBG
+#ifdef EBUG
+#include "strfunc.h"
+extern volatile uint32_t Tms;
+#endif
+
+#include <string.h>
+#include <math.h>
+
+#define BMP280_I2C_ADDRESS_MASK (0x76)
+#define BMP280_I2C_ADDRESS_0  (0x76)
+#define BMP280_I2C_ADDRESS_1  (0x77)
+/**
+ * BMP280 registers
+ */
+#define BMP280_REG_HUM_LSB      0xFE
+#define BMP280_REG_HUM_MSB      0xFD
+#define BMP280_REG_HUM          (BMP280_REG_HUM_MSB)
+#define BMP280_REG_TEMP_XLSB    0xFC /* bits: 7-4 */
+#define BMP280_REG_TEMP_LSB     0xFB
+#define BMP280_REG_TEMP_MSB     0xFA
+#define BMP280_REG_TEMP         (BMP280_REG_TEMP_MSB)
+#define BMP280_REG_PRESS_XLSB   0xF9 /* bits: 7-4 */
+#define BMP280_REG_PRESS_LSB    0xF8
+#define BMP280_REG_PRESS_MSB    0xF7
+#define BMP280_REG_PRESSURE     (BMP280_REG_PRESS_MSB)
+#define BMP280_REG_ALLDATA      (BMP280_REG_PRESS_MSB) // all data: P, T & H
+#define BMP280_REG_CONFIG       0xF5 /* bits: 7-5 t_sb; 4-2 filter; 0 spi3w_en */
+#define BMP280_REG_CTRL         0xF4 /* bits: 7-5 osrs_t; 4-2 osrs_p; 1-0 mode */
+#define BMP280_REG_STATUS       0xF3 /* bits: 3 measuring; 0 im_update */
+#define BMP280_REG_CTRL_HUM     0xF2 /* bits: 2-0 osrs_h; */
+#define BMP280_REG_RESET        0xE0
+#define BMP280_RESET_VALUE      0xB6
+#define BMP280_REG_ID           0xD0
+
+#define BMP280_REG_CALIBA       0x88
+#define BMP280_CALIBA_SIZE      (26)  // 26 bytes of calibration registers sequence from 0x88 to 0xa1
+#define BMP280_CALIBB_SIZE      (7)   // 7 bytes of calibration registers sequence from 0xe1 to 0xe7
+#define BMP280_REG_CALIBB       0xE1
+
+#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 struct {
+    // temperature
+    uint16_t dig_T1;    // 0x88 (LSB), 0x98 (MSB)
+    int16_t  dig_T2;    // ...
+    int16_t  dig_T3;
+    // pressure
+    uint16_t dig_P1;
+    int16_t  dig_P2;
+    int16_t  dig_P3;
+    int16_t  dig_P4;
+    int16_t  dig_P5;
+    int16_t  dig_P6;
+    int16_t  dig_P7;
+    int16_t  dig_P8;
+    int16_t  dig_P9;    // 0x9e, 0x9f
+    // humidity (partially calculated from EEE struct)
+    uint8_t unused;     // 0xA0
+    uint8_t dig_H1;     // 0xA1
+    int16_t dig_H2;     // --------------------
+    uint8_t dig_H3;     // only from EEE
+    uint16_t dig_H4;
+    uint16_t dig_H5;
+    int8_t dig_H6;
+    // data is ready
+    uint8_t  rdy;
+} __attribute__ ((packed)) CaliData = {0};
+
+static struct{
+    BMP280_Filter filter;       // filtering
+    BMP280_Oversampling p_os;   // oversampling for pressure
+    BMP280_Oversampling t_os;   // -//- temperature
+    BMP280_Oversampling h_os;   // -//- humidity
+    uint8_t ID;                 // identificator
+    uint8_t regctl;             // control register base value [(params.t_os << 5) | (params.p_os << 2)]
+} params = {
+    .filter = BMP280_FILTER_OFF,
+    .p_os   = BMP280_OVERS16,
+    .t_os   = BMP280_OVERS16,
+    .h_os   = BMP280_OVERS16,
+    .ID     = 0
+};
+
+static BMP280_status bmpstatus = BMP280_NOTINIT;
+
+BMP280_status BMP280_get_status(){
+    return bmpstatus;
+}
+
+#define SPI_BUFSIZE     (64)
+static uint8_t SPIbuf[SPI_BUFSIZE];
+
+// work with BME280 register over SPI
+static uint8_t *read_regs(uint8_t reg, uint8_t len){
+    if(len > SPI_BUFSIZE-2) return NULL;
+    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 int read_reg(uint8_t reg, uint8_t *val){
+    uint8_t *got = read_regs(reg, 1);
+    if(!got) return 0;
+    if(val) *val = *got;
+    return 1;
+}
+static int write_reg(uint8_t reg, uint8_t val){
+    SPI_CS_0();
+    SPIbuf[0] = reg & 0x7F; // clear MSbit for writing
+    SPIbuf[1] = val;
+    uint8_t r = spi_writeread(SPIbuf, 2);
+    SPI_CS_1();
+    return r;
+}
+
+
+void BMP280_setup(){
+    bmpstatus = BMP280_NOTINIT;
+    spi_setup();
+}
+
+// setters for `params`
+void BMP280_setfilter(BMP280_Filter f){
+    params.filter = f;
+}
+BMP280_Filter BMP280_getfilter(){
+    return params.filter;
+}
+void BMP280_setOSt(BMP280_Oversampling os){
+    params.t_os = os;
+}
+void BMP280_setOSp(BMP280_Oversampling os){
+    params.p_os = os;
+}
+void BMP280_setOSh(BMP280_Oversampling os){
+    params.h_os = os;
+}
+// get compensation data, return 1 if OK
+static int readcompdata(){
+    uint8_t *got = read_regs(BMP280_REG_CALIBA, BMP280_CALIBA_SIZE);
+    if(!got) return 0;
+    memcpy(&CaliData, got, BMP280_CALIBA_SIZE);
+    CaliData.rdy = 1;
+    if(params.ID == BME280_CHIP_ID){
+        got = read_regs(BMP280_REG_CALIBB, BMP280_CALIBB_SIZE);
+        if(got){
+            CaliData.dig_H2 = (got[1] << 8) | got[0];
+            CaliData.dig_H3 = got[2];
+            CaliData.dig_H4 = (got[3] << 4) | (got[4] & 0x0f);
+            CaliData.dig_H5 = (got[5] << 4) | (got[4] >> 4);
+            CaliData.dig_H6 = got[6];
+        }
+    }
+    return 1;
+}
+
+// read compensation data & write registers
+int BMP280_init(){
+    IWDG->KR = IWDG_REFRESH;
+    DBG("INI:");
+    if(!read_reg(BMP280_REG_ID, &params.ID)){
+        DBG("Can't get ID");
+        return 0;
+    }
+    if(params.ID != BMP280_CHIP_ID && params.ID != BME280_CHIP_ID){
+        DBG("Not BMP/BME");
+        return 0;
+    }
+    if(!write_reg(BMP280_REG_RESET, BMP280_RESET_VALUE)){
+        DBG("Can't reset");
+        return 0;
+    }
+    uint8_t 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");
+            return 0;
+        }
+    }
+    if(ntries < 0){
+        DBG("Timeout getting status");
+        return 0;
+    }
+    if(!readcompdata()){
+        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");}
+    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");
+        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");
+            return 0;
+        }
+    }
+    bmpstatus = BMP280_RELAX;
+    return 1;
+}
+
+// @return 1 if OK, *devid -> BMP/BME
+int BMP280_read_ID(uint8_t *devid){
+    if(params.ID != BMP280_CHIP_ID && params.ID != BME280_CHIP_ID) return 0;
+    *devid = params.ID;
+    return 1;
+}
+
+// start measurement, @return 1 if all OK
+int BMP280_start(){
+    if(!CaliData.rdy || bmpstatus == BMP280_BUSY){
+#ifdef EBUG
+        USB_sendstr("rdy="); USB_sendstr(u2str(CaliData.rdy));
+        USB_sendstr("\nbmpstatus="); USB_sendstr(u2str(bmpstatus));
+        newline();
+#endif
+        return 0;
+    }
+    uint8_t reg = params.regctl | BMP280_MODE_FORSED;
+    if(!write_reg(BMP280_REG_CTRL, reg)){
+        DBG("Can't write CTRL reg");
+        return 0;
+    }
+    bmpstatus = BMP280_BUSY;
+    return 1;
+}
+
+void BMP280_process(){
+    if(bmpstatus == BMP280_NOTINIT){
+        BMP280_init(); return;
+    }
+    if(bmpstatus != BMP280_BUSY) return;
+    // BUSY state: poll data ready
+    uint8_t reg;
+    if(!read_reg(BMP280_REG_STATUS, &reg)) return;
+    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(BMP280_REG_ALLDATA, 8);
+        return;
+    }*/
+    bmpstatus = BMP280_RDY; // data ready
+}
+
+// return T*100 degC
+static inline int32_t compTemp(int32_t adc_temp, int32_t *t_fine){
+	int32_t var1, var2;
+	var1 = ((((adc_temp >> 3) - ((int32_t) CaliData.dig_T1 << 1)))
+			* (int32_t) CaliData.dig_T2) >> 11;
+	var2 = (((((adc_temp >> 4) - (int32_t) CaliData.dig_T1)
+			* ((adc_temp >> 4) - (int32_t) CaliData.dig_T1)) >> 12)
+			* (int32_t) CaliData.dig_T3) >> 14;
+	*t_fine = var1 + var2;
+	return (*t_fine * 5 + 128) >> 8;
+}
+
+// return p*256 hPa
+static inline uint32_t compPres(int32_t adc_press, int32_t fine_temp) {
+	int64_t var1, var2, p;
+	var1 = (int64_t) fine_temp - 128000;
+	var2 = var1 * var1 * (int64_t) CaliData.dig_P6;
+	var2 = var2 + ((var1 * (int64_t) CaliData.dig_P5) << 17);
+	var2 = var2 + (((int64_t) CaliData.dig_P4) << 35);
+	var1 = ((var1 * var1 * (int64_t) CaliData.dig_P3) >> 8)
+			+ ((var1 * (int64_t) CaliData.dig_P2) << 12);
+	var1 = (((int64_t) 1 << 47) + var1) * ((int64_t) CaliData.dig_P1) >> 33;
+	if (var1 == 0){
+		return 0;  // avoid exception caused by division by zero
+	}
+	p = 1048576 - adc_press;
+	p = (((p << 31) - var2) * 3125) / var1;
+	var1 = ((int64_t) CaliData.dig_P9 * (p >> 13) * (p >> 13)) >> 25;
+	var2 = ((int64_t) CaliData.dig_P8 * p) >> 19;
+	p = ((p + var1 + var2) >> 8) + ((int64_t) CaliData.dig_P7 << 4);
+	return p;
+}
+
+// return H*1024 %
+static inline uint32_t compHum(int32_t adc_hum, int32_t fine_temp){
+	int32_t v_x1_u32r;
+	v_x1_u32r = fine_temp - (int32_t) 76800;
+	v_x1_u32r = ((((adc_hum << 14) - (((int32_t)CaliData.dig_H4) << 20)
+			- (((int32_t)CaliData.dig_H5) * v_x1_u32r)) + (int32_t)16384) >> 15)
+			* (((((((v_x1_u32r * ((int32_t)CaliData.dig_H6)) >> 10)
+					* (((v_x1_u32r * ((int32_t)CaliData.dig_H3)) >> 11)
+							+ (int32_t)32768)) >> 10) + (int32_t)2097152)
+					* ((int32_t)CaliData.dig_H2) + 8192) >> 14);
+	v_x1_u32r = v_x1_u32r
+			- (((((v_x1_u32r >> 15) * (v_x1_u32r >> 15)) >> 7)
+					* ((int32_t)CaliData.dig_H1)) >> 4);
+	v_x1_u32r = v_x1_u32r < 0 ? 0 : v_x1_u32r;
+	v_x1_u32r = v_x1_u32r > 419430400 ? 419430400 : v_x1_u32r;
+	return v_x1_u32r >> 12;
+}
+
+
+// read data & convert it
+int BMP280_getdata(float *T, float *P, float *H){
+    if(bmpstatus != BMP280_RDY) return 0;
+    bmpstatus = BMP280_RELAX;
+    uint8_t datasz = 8; // amount of bytes to read
+    if(params.ID != BME280_CHIP_ID){
+        if(H) *H = 0;
+        H = NULL;
+        datasz = 6;
+    }
+    uint8_t *data = read_regs(BMP280_REG_ALLDATA, datasz);
+    if(!data) return 0;
+    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;
+    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];
+        *H = ((float)compHum(h, t_fine))/1024.;
+    }
+    return 1;
+}
+
+// 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);
+    if(fabsf(17.27f - gamma) < 1e-3) return -300.f;
+    return (237.7f * gamma)/(17.27f - gamma);
+}
diff --git a/F3:F303/MLX90640-allsky/BMP280.h b/F3:F303/MLX90640-allsky/BMP280.h
new file mode 100644
index 0000000..b5488e4
--- /dev/null
+++ b/F3:F303/MLX90640-allsky/BMP280.h
@@ -0,0 +1,96 @@
+/**
+ * Ciastkolog.pl (https://github.com/ciastkolog)
+ *
+*/
+/**
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2016 sheinz (https://github.com/sheinz)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+/*
+ * 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
+#ifndef BMP280_H__
+#define BMP280_H__
+
+#include <stm32f3.h>
+
+#define BMP280_CHIP_ID  0x58
+#define BME280_CHIP_ID  0x60
+
+typedef enum{ // K for filtering: next = [prev*(k-1) + data_ADC]/k
+    BMP280_FILTER_OFF = 0, // k=1, no filtering
+    BMP280_FILTER_2   = 1, // k=2, 2 samples to reach >75% of data_ADC
+    BMP280_FILTER_4   = 2, // k=4, 5 samples
+    BMP280_FILTER_8   = 3, // k=8, 11 samples
+    BMP280_FILTER_16  = 4, // k=16, 22 samples
+    BMP280_FILTERMAX
+} BMP280_Filter;
+
+typedef enum{ // Number of oversampling
+    BMP280_NOMEASUR = 0,
+    BMP280_OVERS1   = 1,
+    BMP280_OVERS2   = 2,
+    BMP280_OVERS4   = 3,
+    BMP280_OVERS8   = 4,
+    BMP280_OVERS16  = 5,
+    BMP280_OVERSMAX
+} BMP280_Oversampling;
+
+typedef enum{
+    BMP280_NOTINIT,     // wasn't inited
+    BMP280_BUSY,        // measurement in progress
+    BMP280_ERR,         // error in I2C
+    BMP280_RELAX,       // relaxed state
+    BMP280_RDY,         // data ready - can get it
+} BMP280_status;
+
+
+void BMP280_setup();
+int BMP280_init();
+void BMP280_setfilter(BMP280_Filter f);
+BMP280_Filter BMP280_getfilter();
+void BMP280_setOSt(BMP280_Oversampling os);
+void BMP280_setOSp(BMP280_Oversampling os);
+void BMP280_setOSh(BMP280_Oversampling os);
+int BMP280_read_ID(uint8_t *devid);
+BMP280_status BMP280_get_status();
+int BMP280_start();
+void BMP280_process();
+int BMP280_getdata(float *T, float *P, float *H);
+float Tdew(float T, float H);
+
+#endif // BMP280_H__
diff --git a/F3:F303/MLX90640-allsky/Readme.md b/F3:F303/MLX90640-allsky/Readme.md
index f05327d..44789c8 100644
--- a/F3:F303/MLX90640-allsky/Readme.md
+++ b/F3:F303/MLX90640-allsky/Readme.md
@@ -13,21 +13,29 @@ Protocol:
 
 ```
 
+dn - draw nth image in ASCII
+gn - get nth image 'as is' - float array of 768x4 bytes
+l - list active sensors IDs
+mn - show temperature map of nth image
+tn - show nth image aquisition time
+B - reinit BME280
+E - get environment parameters (temperature etc)
+G - get MLX state
+R - reset device
+T - print current Tms
+    Debugging options:
 aa - change I2C address to a (a should be non-shifted value!!!)
 c - continue MLX
-d - draw image in ASCII
 i0..4 - setup I2C with speed 10k, 100k, 400k, 1M or 2M (experimental!)
 p - pause MLX
-r0..3 - change resolution (0 - 16bit, 3 - 19-bit)
-t - show temperature map
-C - "cartoon" mode on/off (show each new image)
-D - dump MLX parameters
-G - get MLX state
-Ia addr - set  device address
+s - stop MLX (and start from zero @ 'c')
+C - "cartoon" mode on/off (show each new image) - USB only!!!
+Dn - dump MLX parameters for sensor number n
+Ia addr [n] - set  device address for interactive work or (with n) change address of n'th sensor
 Ir reg n - read n words from 16-bit register
 Iw words - send words (hex/dec/oct/bin) to I2C
 Is - scan I2C bus
-T - print current Tms
+Us - send string 's' to other interface
 
 
 ```
diff --git a/F3:F303/MLX90640-allsky/allsky.bin b/F3:F303/MLX90640-allsky/allsky.bin
index b8a8e40..81bc8a8 100755
Binary files a/F3:F303/MLX90640-allsky/allsky.bin and b/F3:F303/MLX90640-allsky/allsky.bin differ
diff --git a/F3:F303/MLX90640-allsky/hardware.c b/F3:F303/MLX90640-allsky/hardware.c
index c5623e9..bb9d581 100644
--- a/F3:F303/MLX90640-allsky/hardware.c
+++ b/F3:F303/MLX90640-allsky/hardware.c
@@ -16,19 +16,89 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "BMP280.h"
 #include "hardware.h"
 
-static inline void gpio_setup(){
+static bme280_t environment; // current measurements
+
+#ifndef EBUG
+TRUE_INLINE void iwdg_setup(){
+    uint32_t tmout = 16000000;
+    /* Enable the peripheral clock RTC */
+    /* (1) Enable the LSI (40kHz) */
+    /* (2) Wait while it is not ready */
+    RCC->CSR |= RCC_CSR_LSION; /* (1) */
+    while((RCC->CSR & RCC_CSR_LSIRDY) != RCC_CSR_LSIRDY){if(--tmout == 0) break;} /* (2) */
+    /* Configure IWDG */
+    /* (1) Activate IWDG (not needed if done in option bytes) */
+    /* (2) Enable write access to IWDG registers */
+    /* (3) Set prescaler by 64 (1.6ms for each tick) */
+    /* (4) Set reload value to have a rollover each 2s */
+    /* (5) Check if flags are reset */
+    /* (6) Refresh counter */
+    IWDG->KR = IWDG_START; /* (1) */
+    IWDG->KR = IWDG_WRITE_ACCESS; /* (2) */
+    IWDG->PR = IWDG_PR_PR_1; /* (3) */
+    IWDG->RLR = 1250; /* (4) */
+    tmout = 16000000;
+    while(IWDG->SR){if(--tmout == 0) break;} /* (5) */
+    IWDG->KR = IWDG_REFRESH; /* (6) */
+}
+#endif
+
+TRUE_INLINE void gpio_setup(){
     RCC->AHBENR |= RCC_AHBENR_GPIOAEN | RCC_AHBENR_GPIOBEN; // for USART and LEDs
     for(int i = 0; i < 10000; ++i) nop();
     // 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(){
     gpio_setup();
+#ifndef EBUG
+    iwdg_setup();
+#endif
 }
 
+int bme_init(){
+    BMP280_setup();
+    if(!BMP280_init()) return 0;
+    if(!BMP280_start()) return 0;
+    return 1;
+}
+
+// process sensor and make measurements
+void bme_process(){
+    static uint32_t Tmeas = 0;
+    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;
+            if(s == BMP280_RDY && BMP280_getdata(&Temperature, &Pressure, &Humidity)){
+                environment.Tdew = Tdew(Temperature, Humidity);
+                environment.T = Temperature;
+                environment.P = Pressure;
+                environment.H = Humidity;
+                environment.Tmeas = Tms;
+            }
+            if(Tms - Tmeas > ENV_MEAS_PERIOD-1){
+                if(BMP280_start()) Tmeas = Tms;
+            }
+        }
+    }
+}
+
+int get_environment(bme280_t *env){
+    if(!env) return 0;
+    *env = environment;
+    if(Tms - environment.Tmeas > 2*ENV_MEAS_PERIOD) return 0; // data may be wrong
+    return 1; // good data
+}
diff --git a/F3:F303/MLX90640-allsky/hardware.h b/F3:F303/MLX90640-allsky/hardware.h
index e3a96f8..d9fa981 100644
--- a/F3:F303/MLX90640-allsky/hardware.h
+++ b/F3:F303/MLX90640-allsky/hardware.h
@@ -25,7 +25,24 @@
 #define USBPU_ON()  pin_clear(USBPU_port, USBPU_pin)
 #define USBPU_OFF() pin_set(USBPU_port, USBPU_pin)
 
+// SPI_CS - PB2
+#define SPI_CS_1()      pin_set(GPIOB, 1<<2)
+#define SPI_CS_0()      pin_clear(GPIOB, 1<<2)
+
+// interval of environment measurements, ms
+#define ENV_MEAS_PERIOD (10000)
+
+typedef struct{
+    float T;    // temperature, degC
+    float Tdew; // dew point, degC
+    float P;    // pressure, Pa
+    float H;    // humidity, percents
+    uint32_t Tmeas; // time of measurement
+} bme280_t;
+
 extern volatile uint32_t Tms;
 
 void hw_setup();
-
+int bme_init();
+void bme_process();
+int get_environment(bme280_t *env);
diff --git a/F3:F303/MLX90640-allsky/ir-allsky.creator.user b/F3:F303/MLX90640-allsky/ir-allsky.creator.user
index bc2d899..d7eea8f 100644
--- a/F3:F303/MLX90640-allsky/ir-allsky.creator.user
+++ b/F3:F303/MLX90640-allsky/ir-allsky.creator.user
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE QtCreatorProject>
-<!-- Written by QtCreator 17.0.1, 2025-09-29T22:10:22. -->
+<!-- Written by QtCreator 17.0.1, 2025-10-05T00:09:36. -->
 <qtcreator>
  <data>
   <variable>EnvironmentId</variable>
diff --git a/F3:F303/MLX90640-allsky/ir-allsky.files b/F3:F303/MLX90640-allsky/ir-allsky.files
index 522e29b..eab2e8e 100644
--- a/F3:F303/MLX90640-allsky/ir-allsky.files
+++ b/F3:F303/MLX90640-allsky/ir-allsky.files
@@ -1,3 +1,5 @@
+BMP280.c
+BMP280.h
 hardware.c
 hardware.h
 i2c.c
@@ -15,6 +17,8 @@ proto.c
 proto.h
 ringbuffer.c
 ringbuffer.h
+spi.c
+spi.h
 strfunc.c
 strfunc.h
 usart.c
diff --git a/F3:F303/MLX90640-allsky/main.c b/F3:F303/MLX90640-allsky/main.c
index c2fc250..e7f91b0 100644
--- a/F3:F303/MLX90640-allsky/main.c
+++ b/F3:F303/MLX90640-allsky/main.c
@@ -32,7 +32,7 @@ void sys_tick_handler(void){
     ++Tms;
 }
 
-const char *scanend = "SCANEND\n", *foundid = "FOUNDID=";
+static const char *const scanend = "SCANEND\n", *const foundid = "FOUNDID=";
 
 int main(void){
     char inbuff[MAXSTRLEN+1];
@@ -45,6 +45,7 @@ int main(void){
     USBPU_OFF();
     hw_setup();
     i2c_setup(I2C_SPEED_400K);
+    bme_init();
     USB_setup();
     usart_setup(115200);
     USBPU_ON();
@@ -82,8 +83,9 @@ int main(void){
                 fp_t *im = mlx_getimage(i);
                 if(im){
                     chsendfun(SEND_USB);
-                    U(Sensno); UN(i2str(i));
-                    U(Timage); UN(u2str(Tnow)); drawIma(im);
+                    //U(Sensno); UN(i2str(i));
+                    U(Timage); USB_putbyte('0'+i); USB_putbyte('='); UN(u2str(Tnow));
+                    drawIma(im);
                     Tlastima[i] = Tnow;
                 }
             }
@@ -95,5 +97,6 @@ int main(void){
             const char *ans = parse_cmd(got, SEND_USART);
             if(ans) usart_sendstr(ans);
         }
+        bme_process();
     }
 }
diff --git a/F3:F303/MLX90640-allsky/proto.c b/F3:F303/MLX90640-allsky/proto.c
index 2805c6a..78c8b3c 100644
--- a/F3:F303/MLX90640-allsky/proto.c
+++ b/F3:F303/MLX90640-allsky/proto.c
@@ -20,6 +20,7 @@
 #include <stm32f3.h>
 #include <string.h>
 
+#include "hardware.h"
 #include "i2c.h"
 #include "mlxproc.h"
 #include "proto.h"
@@ -64,36 +65,41 @@ void chsendfun(int sendto){
 #define printfl(x,n)    do{sendfun->S(float2str(x, n));}while(0)
 
 // common names for frequent keys
-const char *Timage = "TIMAGE=";
-const char *Sensno = "SENSNO=";
+const char* const Timage = "TIMAGE";
+const char* const Image = "IMAGE";
+static const char *const Sensno = "SENSNO=";
 
-static const char *OK = "OK\n", *ERR = "ERR\n";
-const char *helpstring =
+static const char *const OK = "OK\n", *const ERR = "ERR\n";
+const char *const helpstring =
         "https://github.com/eddyem/stm32samples/tree/master/F3:F303/MLX90640multi build#" BUILD_NUMBER " @ " BUILD_DATE "\n"
         "    management of single IR bolometer MLX90640\n"
-        "aa - change I2C address to a (a should be non-shifted value!!!)\n"
-        "c - continue MLX\n"
         "dn - draw nth image in ASCII\n"
         "gn - get nth image 'as is' - float array of 768x4 bytes\n"
-        "i0..4 - setup I2C with speed 10k, 100k, 400k, 1M or 2M (experimental!)\n"
         "l - list active sensors IDs\n"
         "mn - show temperature map of nth image\n"
+        "tn - show nth image aquisition time\n"
+        "B - reinit BME280\n"
+        "E - get environment parameters (temperature etc)\n"
+        "G - get MLX state\n"
+        "R - reset device\n"
+        "T - print current Tms\n"
+        "    Debugging options:\n"
+        "aa - change I2C address to a (a should be non-shifted value!!!)\n"
+        "c - continue MLX\n"
+        "i0..4 - setup I2C with speed 10k, 100k, 400k, 1M or 2M (experimental!)\n"
         "p - pause MLX\n"
         "s - stop MLX (and start from zero @ 'c')\n"
-        "tn - show nth image aquisition time\n"
         "C - \"cartoon\" mode on/off (show each new image) - USB only!!!\n"
         "Dn - dump MLX parameters for sensor number n\n"
-        "G - get MLX state\n"
         "Ia addr [n] - set  device address for interactive work or (with n) change address of n'th sensor\n"
         "Ir reg n - read n words from 16-bit register\n"
         "Iw words - send words (hex/dec/oct/bin) to I2C\n"
         "Is - scan I2C bus\n"
-        "T - print current Tms\n"
         "Us - send string 's' to other interface\n"
 ;
 
 TRUE_INLINE const char *setupI2C(char *buf){
-    static const char *speeds[I2C_SPEED_AMOUNT] = {
+    static const char * const speeds[I2C_SPEED_AMOUNT] = {
         [I2C_SPEED_10K] = "10K",
         [I2C_SPEED_100K] = "100K",
         [I2C_SPEED_400K] = "400K",
@@ -207,7 +213,7 @@ TRUE_INLINE void dumpparams(const char *buf){
     if(N < 0){ sendfun->S(ERR); return; }
     MLX90640_params *params = mlx_getparams(N);
     if(!params){ sendfun->S(ERR); return; }
-    sendfun->S(Sensno); sendfun->S(i2str(N)); N();
+    N(); sendfun->S(Sensno); sendfun->S(i2str(N));
     sendfun->S("\nkVdd="); printi(params->kVdd);
     sendfun->S("\nvdd25="); printi(params->vdd25);
     sendfun->S("\nKvPTAT="); printfl(params->KvPTAT, 4);
@@ -263,15 +269,15 @@ TRUE_INLINE void getst(){
     sendfun->S(states[s]); N();
 }
 
-// `draw`==1 - draw, ==0 - show T map, 2 - send raw float array with prefix 'SENSNO=x\nTimage=y\n' and postfix "ENDIMAGE\n"
+// `draw`==1 - draw, ==0 - show T map, 2 - send raw float array with prefix 'TIMAGEX=y\nIMAGEX=' and postfix "ENDIMAGE\n"
 static const char *drawimg(const char *buf, int draw){
     int sensno = getsensnum(buf);
     if(sensno > -1){
         uint32_t T = mlx_lastimT(sensno);
         fp_t *img = mlx_getimage(sensno);
         if(img){
-            sendfun->S(Sensno); sendfun->S(u2str(sensno)); N();
-            sendfun->S(Timage); sendfun->S(u2str(T)); N();
+            //sendfun->S(Sensno); sendfun->S(u2str(sensno)); N();
+            sendfun->S(Timage); sendfun->P('0'+sensno); sendfun->P('='); sendfun->S(u2str(T)); N();
             switch(draw){
                 case 0:
                     dumpIma(img);
@@ -280,7 +286,7 @@ static const char *drawimg(const char *buf, int draw){
                     drawIma(img);
                 break;
                 case 2:
-                {
+                    sendfun->S(Image); sendfun->P('0'+sensno); sendfun->P('=');
                     uint8_t *d = (uint8_t*)img;
                     uint32_t _2send = MLX_PIXNO * sizeof(float);
                     // send by portions of 256 bytes (as image is larger than ringbuffer)
@@ -290,8 +296,8 @@ static const char *drawimg(const char *buf, int draw){
                         _2send -= portion;
                         d += portion;
                     }
-                }
                     sendfun->S("ENDIMAGE"); N();
+                break;
             }
             return NULL;
         }
@@ -317,10 +323,22 @@ TRUE_INLINE void listactive(){
 static void getimt(const char *buf){
     int sensno = getsensnum(buf);
     if(sensno > -1){
-        sendfun->S(Timage); sendfun->S(u2str(mlx_lastimT(sensno))); N();
+        sendfun->S(Timage); sendfun->P('0'+sensno); sendfun->P('='); sendfun->S(u2str(mlx_lastimT(sensno))); N();
     }else sendfun->S(ERR);
 }
 
+TRUE_INLINE void getenv(){
+    bme280_t env;
+    if(!get_environment(&env)) sendfun->S("BADENVIRONMENT\n");
+    sendfun->S("TEMPERATURE="); sendfun->S(float2str(env.T, 2));
+    sendfun->S("\nPRESSURE_HPA="); sendfun->S(float2str(env.P/100.f, 2));
+    sendfun->S("\nPRESSURE_MM="); sendfun->S(float2str(env.P * 0.00750062f, 2));
+    sendfun->S("\nHUMIDITY="); sendfun->S(float2str(env.H, 2));
+    sendfun->S("\nTEMP_DEW="); sendfun->S(float2str(env.Tdew, 1));
+    sendfun->S("\nT_MEASUREMENT="); sendfun->S(u2str(env.Tmeas));
+    N();
+}
+
 /**
  * @brief parse_cmd - user string parser
  * @param buf - user data
@@ -386,12 +404,21 @@ const char *parse_cmd(char *buf, int sendto){
         break;
         case 's':
             mlx_stop(); return OK;
+        case 'B':
+            if(bme_init()) return OK;
+            return ERR;
         case 'C':
             if(sendto != SEND_USB) return ERR;
             cartoon = !cartoon; return OK;
+        case 'E':
+            getenv();
+        break;
         case 'G':
             getst();
         break;
+        case 'R':
+            NVIC_SystemReset();
+        break;
         case 'T':
             sendfun->S("T="); sendfun->S(u2str(Tms)); N();
         break;
@@ -420,7 +447,7 @@ void dumpIma(const fp_t im[MLX_PIXNO]){
 
 #define GRAY_LEVELS     (16)
 // 16-level character set ordered by fill percentage (provided by user)
-static const char* CHARS_16 = " .':;+*oxX#&%B$@";
+static const char *const CHARS_16 = " .':;+*oxX#&%B$@";
 // draw image in ASCII-art
 void drawIma(const fp_t im[MLX_PIXNO]){
     // Find min and max values
diff --git a/F3:F303/MLX90640-allsky/proto.h b/F3:F303/MLX90640-allsky/proto.h
index 398ba7a..aab3d44 100644
--- a/F3:F303/MLX90640-allsky/proto.h
+++ b/F3:F303/MLX90640-allsky/proto.h
@@ -18,7 +18,7 @@
 
 #pragma once
 
-extern const char *Timage, *Sensno;
+extern const char *const Timage;
 
 #define SEND_USB    (1)
 #define SEND_USART  (0)
diff --git a/F3:F303/MLX90640-allsky/spi.c b/F3:F303/MLX90640-allsky/spi.c
new file mode 100644
index 0000000..646b01e
--- /dev/null
+++ b/F3:F303/MLX90640-allsky/spi.c
@@ -0,0 +1,113 @@
+/*
+ * This file is part of the ir-allsky project.
+ * Copyright 2025 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 "hardware.h"
+#include "spi.h"
+#include <string.h> // memcpy
+
+#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 @ ~280kHz (36MHz/128)
+void spi_setup(){
+    SPI1->CR1 = 0; // clear EN
+    SPI1->CR2 = 0;
+    // PB3 - SCK, BP4 - MISO, PB5 - MOSI; AF5 @PB3-5
+    GPIOB->AFR[0] = (GPIOB->AFR[0] & ~(GPIO_AFRL_AFRL3 | GPIO_AFRL_AFRL4 | GPIO_AFRL_AFRL5)) |
+                    AFRf(5, 3) | AFRf(5, 4) | AFRf(5, 5);
+    GPIOB->MODER = (GPIOB->MODER & (MODER_CLR(3) & MODER_CLR(4) & MODER_CLR(5))) |
+                    MODER_AF(3) | MODER_AF(4) | MODER_AF(5);
+    RCC->APB1RSTR = RCC_APB2RSTR_SPI1RST;
+    RCC->APB1RSTR = 0; // clear reset
+    RCC->APB2ENR |= RCC_APB2ENR_SPI1EN;
+    // software slave management (without hardware NSS pin); RX only; Baudrate = 0b110 - fpclk/128
+    // CPOL=1, CPHA=1:
+    SPI1->CR1 = SPI_CR1_CPOL | SPI_CR1_CPHA | SPI_CR1_SSM | SPI_CR1_SSI | SPI_CR1_MSTR | SPI_CR1_BR_2 | SPI_CR1_BR_1;
+    // hardware NSS management, RXNE after 8bit; 8bit transfer (default)
+    // DS=8bit; RXNE generates after 8bit of data in FIFO;
+    SPI1->CR2 = SPI_CR2_SSOE | SPI_CR2_FRXTH | SPI_CR2_DS_2|SPI_CR2_DS_1|SPI_CR2_DS_0;
+    spi_status = SPI_READY;
+    DBG("SPI works");
+}
+
+void spi_onoff(uint8_t on){
+    if(on) SPI1->CR1 |= SPI_CR1_SPE;
+    else SPI1->CR1 &= ~SPI_CR1_SPE;
+}
+
+// turn off given SPI channel and release GPIO
+void spi_deinit(){
+    SPI1->CR1 = 0;
+    SPI1->CR2 = 0;
+    RCC->APB2ENR &= ~RCC_APB2ENR_SPI1EN;
+    GPIOB->AFR[0] = GPIOB->AFR[0] & ~(GPIO_AFRL_AFRL3 | GPIO_AFRL_AFRL4 | GPIO_AFRL_AFRL5);
+    GPIOB->MODER = GPIOB->MODER & (MODER_CLR(3) & MODER_CLR(4) & MODER_CLR(5));
+    spi_status = SPI_NOTREADY;
+}
+
+uint8_t spi_waitbsy(){
+    WAITX(SPI1->SR & SPI_SR_BSY);
+    return 1;
+}
+
+/**
+ * @brief spi_writeread - send data over SPI (change data array with received bytes)
+ * @param data - data to write/read
+ * @param n - length of data
+ * @return 0 if failed
+ */
+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));
+        *((volatile uint8_t*)&SPI1->DR) = data[x];
+        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
+uint8_t spi_read(uint8_t *data, uint8_t n){
+    if(spi_status != SPI_READY || !data || !n){
+        DBG("not ready");
+        return 0;
+    }
+    // clear SPI Rx FIFO
+    for(int i = 0; i < 4; ++i) (void) SPI1->DR;
+    spi_onoff(TRUE);
+    for(int x = 0; x < n; ++x){
+        WAITX(!(SPI1->SR & SPI_SR_RXNE));
+        data[x] = *((volatile uint8_t*)&SPI1->DR);
+    }
+    spi_onoff(FALSE); // turn off SPI
+    return 1;
+}
+
diff --git a/F3:F303/MLX90640-allsky/spi.h b/F3:F303/MLX90640-allsky/spi.h
new file mode 100644
index 0000000..e956f08
--- /dev/null
+++ b/F3:F303/MLX90640-allsky/spi.h
@@ -0,0 +1,35 @@
+/*
+ * This file is part of the ir-allsky project.
+ * Copyright 2025 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 <stm32f3.h>
+
+typedef enum{
+    SPI_NOTREADY,
+    SPI_READY,
+    SPI_BUSY
+} spiStatus;
+
+extern spiStatus spi_status;
+
+void spi_onoff(uint8_t on);
+void spi_deinit();
+void spi_setup();
+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/MLX90640-allsky/usb_dev.c b/F3:F303/MLX90640-allsky/usb_dev.c
index 8e519e4..8d61eee 100644
--- a/F3:F303/MLX90640-allsky/usb_dev.c
+++ b/F3:F303/MLX90640-allsky/usb_dev.c
@@ -165,7 +165,16 @@ int USB_sendall(){
 int USB_send(const uint8_t *buf, int len){
     if(!buf || !CDCready || !len) return FALSE;
     while(len){
-        int a = RB_write((ringbuffer*)&rbout, buf, len);
+        IWDG->KR = IWDG_REFRESH;
+        int l = RB_datalen((ringbuffer*)&rbout);
+        if(l < 0) continue;
+        int portion = rbout.length - 1 - l;
+        if(portion < 1){
+            if(lastdsz == 0) send_next();
+            continue;
+        }
+        if(portion > len) portion = len;
+        int a = RB_write((ringbuffer*)&rbout, buf, portion);
         if(a > 0){
             len -= a;
             buf += a;
diff --git a/F3:F303/MLX90640-allsky/usb_dev.h b/F3:F303/MLX90640-allsky/usb_dev.h
index a85227c..7be0410 100644
--- a/F3:F303/MLX90640-allsky/usb_dev.h
+++ b/F3:F303/MLX90640-allsky/usb_dev.h
@@ -50,6 +50,12 @@ void linecoding_handler(usb_LineCoding *lc);
 #define UN(s)     do{USB_sendstr(s); USB_putbyte('\n');}while(0)
 #define U(s)        USB_sendstr(s)
 
+#ifdef EBUG
+#define DBG(s)      do{USB_sendstr(s); USB_putbyte('\n');}while(0)
+#else
+#define DBG(s)
+#endif
+
 int USB_sendall();
 int USB_send(const uint8_t *buf, int len);
 int USB_putbyte(uint8_t byte);
diff --git a/F3:F303/MLX90640-allsky/version.inc b/F3:F303/MLX90640-allsky/version.inc
index 3b34625..74584f0 100644
--- a/F3:F303/MLX90640-allsky/version.inc
+++ b/F3:F303/MLX90640-allsky/version.inc
@@ -1,2 +1,2 @@
-#define BUILD_NUMBER "15"
-#define BUILD_DATE "2025-09-29"
+#define BUILD_NUMBER "36"
+#define BUILD_DATE "2025-10-05"