diff --git a/F0:F030,F042,F072/usbcan_gpio/usbcangpio.creator.user b/F0:F030,F042,F072/usbcan_gpio/usbcangpio.creator.user
index 1ffe426..2bc265d 100644
--- a/F0:F030,F042,F072/usbcan_gpio/usbcangpio.creator.user
+++ b/F0:F030,F042,F072/usbcan_gpio/usbcangpio.creator.user
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE QtCreatorProject>
-<!-- Written by QtCreator 18.0.2, 2026-03-18T23:46:41. -->
+<!-- Written by QtCreator 19.0.0, 2026-03-23T23:04:04. -->
 <qtcreator>
  <data>
   <variable>EnvironmentId</variable>
@@ -155,6 +155,7 @@
      <value type="bool" key="Analyzer.QmlProfiler.Settings.UseGlobalSettings">true</value>
      <value type="int" key="Analyzer.Valgrind.Callgrind.CostFormat">0</value>
      <value type="bool" key="Analyzer.Valgrind.Settings.UseGlobalSettings">true</value>
+     <valuelist type="QVariantList" key="Analyzer.Valgrind.SuppressionFiles"/>
      <value type="QList&lt;int&gt;" key="Analyzer.Valgrind.VisibleErrorKinds"></value>
      <valuelist type="QVariantList" key="CustomOutputParsers"/>
      <value type="int" key="PE.EnvironmentAspect.Base">2</value>
@@ -190,6 +191,7 @@
     <value type="bool" key="Analyzer.QmlProfiler.Settings.UseGlobalSettings">true</value>
     <value type="int" key="Analyzer.Valgrind.Callgrind.CostFormat">0</value>
     <value type="bool" key="Analyzer.Valgrind.Settings.UseGlobalSettings">true</value>
+    <valuelist type="QVariantList" key="Analyzer.Valgrind.SuppressionFiles"/>
     <value type="QList&lt;int&gt;" key="Analyzer.Valgrind.VisibleErrorKinds"></value>
     <valuelist type="QVariantList" key="CustomOutputParsers"/>
     <value type="int" key="PE.EnvironmentAspect.Base">2</value>
diff --git a/F1:F103/BISS_C_encoders/Makefile b/F1:F103/BISS_C_encoders/Makefile
index 8496007..3aa2506 100644
--- a/F1:F103/BISS_C_encoders/Makefile
+++ b/F1:F103/BISS_C_encoders/Makefile
@@ -6,4 +6,4 @@ LDSCRIPT    ?= stm32f103xB.ld
 DEFINES := -DSTM32F10X_MD
 
 include ../makefile.f1
-include ../makefile.stm32
+include ../../makefile.stm32
diff --git a/F1:F103/BISS_C_encoders/encoders.bin b/F1:F103/BISS_C_encoders/encoders.bin
index efe98a1..0068880 100755
Binary files a/F1:F103/BISS_C_encoders/encoders.bin and b/F1:F103/BISS_C_encoders/encoders.bin differ
diff --git a/F1:F103/BISS_C_encoders/encoders.creator.user b/F1:F103/BISS_C_encoders/encoders.creator.user
index 32c15f4..df0650b 100644
--- a/F1:F103/BISS_C_encoders/encoders.creator.user
+++ b/F1:F103/BISS_C_encoders/encoders.creator.user
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE QtCreatorProject>
-<!-- Written by QtCreator 18.0.2, 2026-02-13T20:51:37. -->
+<!-- Written by QtCreator 19.0.0, 2026-03-23T23:04:02. -->
 <qtcreator>
  <data>
   <variable>EnvironmentId</variable>
@@ -154,6 +154,7 @@
      <value type="bool" key="Analyzer.QmlProfiler.Settings.UseGlobalSettings">true</value>
      <value type="int" key="Analyzer.Valgrind.Callgrind.CostFormat">0</value>
      <value type="bool" key="Analyzer.Valgrind.Settings.UseGlobalSettings">true</value>
+     <valuelist type="QVariantList" key="Analyzer.Valgrind.SuppressionFiles"/>
      <value type="QList&lt;int&gt;" key="Analyzer.Valgrind.VisibleErrorKinds"></value>
      <valuelist type="QVariantList" key="CustomOutputParsers"/>
      <value type="int" key="PE.EnvironmentAspect.Base">2</value>
@@ -189,6 +190,7 @@
     <value type="bool" key="Analyzer.QmlProfiler.Settings.UseGlobalSettings">true</value>
     <value type="int" key="Analyzer.Valgrind.Callgrind.CostFormat">0</value>
     <value type="bool" key="Analyzer.Valgrind.Settings.UseGlobalSettings">true</value>
+    <valuelist type="QVariantList" key="Analyzer.Valgrind.SuppressionFiles"/>
     <value type="QList&lt;int&gt;" key="Analyzer.Valgrind.VisibleErrorKinds"></value>
     <valuelist type="QVariantList" key="CustomOutputParsers"/>
     <value type="int" key="PE.EnvironmentAspect.Base">2</value>
diff --git a/F1:F103/BISS_C_encoders/flash.h b/F1:F103/BISS_C_encoders/flash.h
index 2a8266a..6177fe7 100644
--- a/F1:F103/BISS_C_encoders/flash.h
+++ b/F1:F103/BISS_C_encoders/flash.h
@@ -47,8 +47,8 @@ typedef struct{
 typedef struct __attribute__((packed, aligned(4))){
     uint16_t userconf_sz;       // "magick number"
     uint16_t send232_interval;  // interval (ms) of sending data to SSII over RS-232 (or 0 - not to send)
-    uint16_t iInterface[bTotNumEndpoints][MAX_IINTERFACE_SZ]; // hryunikod!
-    uint8_t iIlengths[bTotNumEndpoints];
+    uint16_t iInterface[InterfacesAmount][MAX_IINTERFACE_SZ]; // hryunikod!
+    uint8_t iIlengths[InterfacesAmount];
     uint8_t encbits;    // encoder bits: 26 or 32
     uint8_t encbufsz;   // encoder buffer size (up to ENCODER_BUFSZ_MAX)
     uint8_t minzeros;   // min/max zeros in preamble when searching start of record
diff --git a/F1:F103/BISS_C_encoders/main.c b/F1:F103/BISS_C_encoders/main.c
index 5a3f87a..f6ac060 100644
--- a/F1:F103/BISS_C_encoders/main.c
+++ b/F1:F103/BISS_C_encoders/main.c
@@ -124,7 +124,7 @@ static void proc_enc(uint8_t idx){
 
 int main(){
     uint32_t lastT = 0, usartT = 0;
-    uint8_t oldCDCready[bTotNumEndpoints] = {0};
+    uint8_t oldCDCready[InterfacesAmount] = {0};
     StartHSE();
     flashstorage_init();
     hw_setup();
@@ -148,7 +148,7 @@ int main(){
             else if(l) parse_cmd(inbuff);
             // check if interface connected/disconnected
             // (we CAN'T do much debug output in interrupt functions like linecoding_handler etc, so do it here)
-            for(int i = 1; i < bTotNumEndpoints; ++i){
+            for(int i = 1; i < InterfacesAmount; ++i){
                 if(oldCDCready[i] != CDCready[i]){
                     CMDWR("Interface ");
                     CMDWR(u2str(i));
diff --git a/F1:F103/BISS_C_encoders/proto.c b/F1:F103/BISS_C_encoders/proto.c
index b096ddb..0438baa 100644
--- a/F1:F103/BISS_C_encoders/proto.c
+++ b/F1:F103/BISS_C_encoders/proto.c
@@ -133,7 +133,7 @@ static errcode_e sendenc(cmd_e idx, char *par){
 }
 
 static errcode_e setiface(cmd_e idx, char *par){
-    if(idx < C_setiface1 || idx >= C_setiface1 + bTotNumEndpoints) return ERR_BADCMD;
+    if(idx < C_setiface1 || idx >= C_setiface1 + InterfacesAmount) return ERR_BADCMD;
     idx -= C_setiface1; // now it is an index of iIlengths
     if(par && *par){
         int l = strlen(par);
@@ -364,7 +364,7 @@ static errcode_e dumpconf(cmd_e _U_ idx, char _U_ *par){
     CMDWR("userconf_sz="); CMDWR(u2str(the_conf.userconf_sz));
     CMDWR("\ncurrentconfidx="); CMDWR(i2str(currentconfidx));
     CMDn();
-    for(int i = 0; i < bTotNumEndpoints; ++i)
+    for(int i = 0; i < InterfacesAmount; ++i)
         setiface(C_setiface1 + i, NULL);
     setboolpar(C_autom, NULL);
     setuintpar(C_amperiod, NULL);
diff --git a/F1:F103/BISS_C_encoders/ringbuffer.c b/F1:F103/BISS_C_encoders/ringbuffer.c
index d444ec6..bc2af8d 100644
--- a/F1:F103/BISS_C_encoders/ringbuffer.c
+++ b/F1:F103/BISS_C_encoders/ringbuffer.c
@@ -15,9 +15,12 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include <string.h> // memcpy
+#include <string.h>
+
 #include "ringbuffer.h"
 
+#define CHK(b)  do{if(!b) return -1;}while(0)
+
 static int datalen(ringbuffer *b){
     if(b->tail >= b->head) return (b->tail - b->head);
     else return (b->length - b->head + b->tail);
@@ -25,6 +28,8 @@ static int datalen(ringbuffer *b){
 
 // stored data length
 int RB_datalen(ringbuffer *b){
+    CHK(b);
+    if(0 == datalen(b)) return 0; // don't block for empty RO operations
     if(b->busy) return -1;
     b->busy = 1;
     int l = datalen(b);
@@ -52,17 +57,13 @@ static int hasbyte(ringbuffer *b, uint8_t byte){
  * @return index if found, -1 if none or busy
  */
 int RB_hasbyte(ringbuffer *b, uint8_t byte){
+    CHK(b);
     if(b->busy) return -1;
     b->busy = 1;
     int ret = hasbyte(b, byte);
     b->busy = 0;
     return ret;
 }
-/*
-// poor memcpy
-static void mcpy(uint8_t *targ, const uint8_t *src, int l){
-    while(l--) *targ++ = *src++;
-}*/
 
 // increment head or tail
 TRUE_INLINE void incr(ringbuffer *b, volatile int *what, int n){
@@ -77,10 +78,8 @@ static int read(ringbuffer *b, uint8_t *s, int len){
     int _1st = b->length - b->head;
     if(_1st > l) _1st = l;
     if(_1st > len) _1st = len;
-    //mcpy(s, b->data + b->head, _1st);
     memcpy(s, b->data + b->head, _1st);
     if(_1st < len && l > _1st){
-        //mcpy(s+_1st, b->data, l - _1st);
         memcpy(s+_1st, b->data, l - _1st);
         incr(b, &b->head, l);
         return l;
@@ -97,6 +96,9 @@ static int read(ringbuffer *b, uint8_t *s, int len){
  * @return bytes read or -1 if busy
  */
 int RB_read(ringbuffer *b, uint8_t *s, int len){
+    CHK(b);
+    if(!s || len < 1) return -1;
+    if(0 == datalen(b)) return 0;
     if(b->busy) return -1;
     b->busy = 1;
     int r = read(b, s, len);
@@ -104,13 +106,20 @@ int RB_read(ringbuffer *b, uint8_t *s, int len){
     return r;
 }
 
-static int readto(ringbuffer *b, uint8_t byte, uint8_t *s, int len){
+// length of data from current position to `byte` (including byte)
+static int lento(ringbuffer *b, uint8_t byte){
     int idx = hasbyte(b, byte);
     if(idx < 0) return 0;
     int partlen = idx + 1 - b->head;
     // now calculate length of new data portion
     if(idx < b->head) partlen += b->length;
-    if(partlen > len) return -read(b, s, len);
+    return partlen;
+}
+
+static int readto(ringbuffer *b, uint8_t byte, uint8_t *s, int len){
+    int partlen = lento(b, byte);
+    if(!partlen) return 0;
+    if(partlen > len) return -1;
     return read(b, s, partlen);
 }
 
@@ -118,27 +127,45 @@ static int readto(ringbuffer *b, uint8_t byte, uint8_t *s, int len){
  * @brief RB_readto fill array `s` with data until byte `byte` (with it)
  * @param b - ringbuffer
  * @param byte - check byte
- * @param s - buffer to write data
- * @param len - length of `s`
+ * @param s - buffer to write data or NULL to clear data
+ * @param len - length of `s` or 0 to clear data
  * @return amount of bytes written (negative, if len<data in buffer or buffer is busy)
  */
 int RB_readto(ringbuffer *b, uint8_t byte, uint8_t *s, int len){
+    CHK(b);
+    if(!s || len < 1) return -1;
+    if(0 == datalen(b)) return 0;
     if(b->busy) return -1;
     b->busy = 1;
-    int n = readto(b, byte, s, len);
+    int n = 0;
+    if(s && len > 0){
+        n = readto(b, byte, s, len);
+    }else{
+        incr(b, &b->head, lento(b, byte)); // just throw data out
+    }
     b->busy = 0;
     return n;
 }
 
+int RB_datalento(ringbuffer *b, uint8_t byte){
+    CHK(b);
+    if(0 == datalen(b)) return 0;
+    if(b->busy) return -1;
+    b->busy = 1;
+    int n = lento(b, byte);
+    b->busy = 0;
+    return n;
+}
+
+// if l < rest of buffer, truncate and return actually written bytes
 static int write(ringbuffer *b, const uint8_t *str, int l){
     int r = b->length - 1 - datalen(b); // rest length
-    if(l > r || !l) return 0;
+    if(r < 1) return 0;
+    if(l > r) l = r;
     int _1st = b->length - b->tail;
     if(_1st > l) _1st = l;
-    //mcpy(b->data + b->tail, str, _1st);
     memcpy(b->data + b->tail, str, _1st);
     if(_1st < l){ // add another piece from start
-        //mcpy(b->data, str+_1st, l-_1st);
         memcpy(b->data, str+_1st, l-_1st);
     }
     incr(b, &b->tail, l);
@@ -153,6 +180,9 @@ static int write(ringbuffer *b, const uint8_t *str, int l){
  * @return amount of bytes written or -1 if busy
  */
 int RB_write(ringbuffer *b, const uint8_t *str, int l){
+    CHK(b);
+    if(!str || l < 1) return -1;
+    if(b->length - datalen(b) < 2) return 0;
     if(b->busy) return -1;
     b->busy = 1;
     int w = write(b, str, l);
@@ -162,10 +192,12 @@ int RB_write(ringbuffer *b, const uint8_t *str, int l){
 
 // just delete all information in buffer `b`
 int RB_clearbuf(ringbuffer *b){
+    CHK(b);
     if(b->busy) return -1;
     b->busy = 1;
     b->head = 0;
     b->tail = 0;
+    bzero(b->data, b->length);
     b->busy = 0;
     return 1;
 }
diff --git a/F1:F103/BISS_C_encoders/ringbuffer.h b/F1:F103/BISS_C_encoders/ringbuffer.h
index 5643b5a..e7312bb 100644
--- a/F1:F103/BISS_C_encoders/ringbuffer.h
+++ b/F1:F103/BISS_C_encoders/ringbuffer.h
@@ -17,6 +17,8 @@
 
 #pragma once
 
+#include <stdint.h>
+
 #if defined STM32F0
 #include <stm32f0.h>
 #elif defined STM32F1
@@ -25,14 +27,12 @@
 #include <stm32f3.h>
 #endif
 
-#include <stdatomic.h>
-
 typedef struct{
     uint8_t *data;      // data buffer
     const int length;   // its length
     int head;           // head index
     int tail;           // tail index
-    volatile atomic_int busy; // == TRUE if buffer is busy now
+    volatile int busy; // == TRUE if buffer is busy now
 } ringbuffer;
 
 int RB_read(ringbuffer *b, uint8_t *s, int len);
@@ -40,4 +40,5 @@ int RB_readto(ringbuffer *b, uint8_t byte, uint8_t *s, int len);
 int RB_hasbyte(ringbuffer *b, uint8_t byte);
 int RB_write(ringbuffer *b, const uint8_t *str, int l);
 int RB_datalen(ringbuffer *b);
+int RB_datalento(ringbuffer *b, uint8_t byte);
 int RB_clearbuf(ringbuffer *b);
diff --git a/F1:F103/BISS_C_encoders/usb_descr.c b/F1:F103/BISS_C_encoders/usb_descr.c
index fd1688d..233d5af 100644
--- a/F1:F103/BISS_C_encoders/usb_descr.c
+++ b/F1:F103/BISS_C_encoders/usb_descr.c
@@ -20,11 +20,6 @@
 #include "flash.h"
 #include "usb_descr.h"
 
-#undef DBG
-#define DBG(x)
-#undef DBGs
-#define DBGs(x)
-
 // low/high for uint16_t
 #define L16(x)              (x & 0xff)
 #define H16(x)              (x >> 8)
@@ -63,7 +58,7 @@ static const uint8_t USB_DeviceQualifierDescriptor[] = {
     0 // Reserved
 };
 
-#define wTotalLength  (USB_DT_CONFIG_SIZE + bTotNumEndpoints * 66)
+#define wTotalLength  (USB_DT_CONFIG_SIZE + (bTotNumEndpoints * 66))
 
 /*
  *  _1stI - number of first interface
@@ -166,7 +161,7 @@ static const uint8_t USB_ConfigDescriptor[] = {
 //const uint8_t HID_ReportDescriptor[];
 
 _USB_LANG_ID_(LD, LANG_US);
-_USB_STRING_(SD, u"0.0.1");
+_USB_STRING_(SD, u"0.0.2");
 _USB_STRING_(MD, u"eddy@sao.ru");
 _USB_STRING_(PD, u"USB BISS-C encoders controller");
 
@@ -177,7 +172,7 @@ typedef struct{
     uint8_t  bDescriptorType;
     uint16_t bString[MAX_IINTERFACE_SZ];
 }iidescr_t;
-static iidescr_t iids[bTotNumEndpoints] = {
+static iidescr_t iids[InterfacesAmount] = {
     _USB_IIDESCR_(u"encoder_cmd"),
     _USB_IIDESCR_(u"encoder_X"),
     _USB_IIDESCR_(u"encoder_Y"),
@@ -197,12 +192,8 @@ static void wr0(const uint8_t *buf, uint16_t size, uint16_t askedsize){
     if(askedsize < size) size = askedsize; // shortened request
     if(size < USB_EP0BUFSZ){
         EP_WriteIRQ(0, buf, size);
-        DBG("short wr0");
-        DBGs(uhex2str(size));
         return;
     }
-    DBG("long wr0");
-    DBGs(uhex2str(size));
     while(size){
         uint16_t l = size;
         if(l > USB_EP0BUFSZ) l = USB_EP0BUFSZ;
@@ -215,7 +206,7 @@ static void wr0(const uint8_t *buf, uint16_t size, uint16_t askedsize){
             // keep DTOGs, clear CTR_RX,TX, set TX VALID, leave stat_Rx
             USB->EPnR[0] = (epstatus & ~(USB_EPnR_CTR_RX|USB_EPnR_CTR_TX|USB_EPnR_STAT_RX))
                            ^ USB_EPnR_STAT_TX;
-            uint32_t ctr = 10000;
+            uint32_t ctr = 1000000;
             while(--ctr && (USB->ISTR & USB_ISTR_CTR) == 0){IWDG->KR = IWDG_REFRESH;};
             if((USB->ISTR & USB_ISTR_CTR) == 0){
                 return;
@@ -229,42 +220,32 @@ void get_descriptor(config_pack_t *pack){
     uint8_t descrtype = pack->wValue >> 8,
         descridx = pack->wValue & 0xff;
     switch(descrtype){
-        case DEVICE_DESCRIPTOR:
-            DBG("DEVICE_DESCRIPTOR");
-            wr0(USB_DeviceDescriptor, sizeof(USB_DeviceDescriptor), pack->wLength);
-            break;
-        case CONFIGURATION_DESCRIPTOR:
-            DBG("CONFIGURATION_DESCRIPTOR");
-            wr0(USB_ConfigDescriptor, sizeof(USB_ConfigDescriptor), pack->wLength);
-            break;
-        case STRING_DESCRIPTOR:
-            DBG("STRING_DESCRIPTOR");
-            if(descridx < iDESCR_AMOUNT){
-                wr0((const uint8_t *)StringDescriptor[descridx], *((uint8_t*)StringDescriptor[descridx]), pack->wLength);
-                DBGs(uhex2str(descridx));
-            }else{
-                EP_WriteIRQ(0, NULL, 0);
-                DBG("Wrong index");
-                DBGs(uhex2str(descridx));
-            }
-            break;
-        case DEVICE_QUALIFIER_DESCRIPTOR:
-            DBG("DEVICE_QUALIFIER_DESCRIPTOR");
-            wr0(USB_DeviceQualifierDescriptor, sizeof(USB_DeviceQualifierDescriptor), pack->wLength);
-            break;
-       /* case HID_REPORT_DESCRIPTOR:
-            wr0(HID_ReportDescriptor, sizeof(HID_ReportDescriptor), pack->wLength);
-            break;*/
-        default:
-            break;
+    case DEVICE_DESCRIPTOR:
+        wr0(USB_DeviceDescriptor, sizeof(USB_DeviceDescriptor), pack->wLength);
+        break;
+    case CONFIGURATION_DESCRIPTOR:
+        wr0(USB_ConfigDescriptor, sizeof(USB_ConfigDescriptor), pack->wLength);
+        break;
+    case STRING_DESCRIPTOR:
+        if(descridx < iDESCR_AMOUNT){
+            wr0((const uint8_t *)StringDescriptor[descridx], *((uint8_t*)StringDescriptor[descridx]), pack->wLength);
+        }else{
+            EP_WriteIRQ(0, NULL, 0);
+        }
+        break;
+    case DEVICE_QUALIFIER_DESCRIPTOR:
+        wr0(USB_DeviceQualifierDescriptor, sizeof(USB_DeviceQualifierDescriptor), pack->wLength);
+        break;
+    default:
+        break;
     }
 }
 
 // change values of iInterface by content of global config
 void setup_interfaces(){
-    for(int i = 0; i < bTotNumEndpoints; ++i){
+    for(int i = 0; i < InterfacesAmount; ++i){
         if(the_conf.iIlengths[i]){
-            iids[i].bLength = the_conf.iIlengths[i];
+            iids[i].bLength = the_conf.iIlengths[i] + 2; // +2 - for bLength and bDescriptorType
             memcpy(iids[i].bString, the_conf.iInterface[i], the_conf.iIlengths[i]);
         }
         iids[i].bDescriptorType = 0x03;
diff --git a/F1:F103/BISS_C_encoders/usb_descr.h b/F1:F103/BISS_C_encoders/usb_descr.h
index 8c0ffd2..6654d70 100644
--- a/F1:F103/BISS_C_encoders/usb_descr.h
+++ b/F1:F103/BISS_C_encoders/usb_descr.h
@@ -32,8 +32,16 @@
 #define bNumConfigurations  1
 
 // amount of interfaces and endpoints (except 0) used
-#define bNumInterfaces      6
-#define bTotNumEndpoints    3
+#define InterfacesAmount    3
+// EP number of interface
+#define EPNO(i) (i + 1)
+// interface number of EPno
+#define IFNO(e) (e - 1)
+
+// amount of interfaces (including virtual) except 0
+#define bNumInterfaces      (2*InterfacesAmount)
+// amount of endpoints used
+#define bTotNumEndpoints    (1+InterfacesAmount)
 
 // powered
 #define BusPowered          (1<<7)
diff --git a/F1:F103/BISS_C_encoders/usb_dev.c b/F1:F103/BISS_C_encoders/usb_dev.c
index b61aea8..c420d2a 100644
--- a/F1:F103/BISS_C_encoders/usb_dev.c
+++ b/F1:F103/BISS_C_encoders/usb_dev.c
@@ -38,56 +38,41 @@
 #define CONTROL_DTR                     0x01
 #define CONTROL_RTS                     0x02
 
-// It's good to use debug here ONLY to debug into USART!
-// never try to debug USB into USB!!!
-#undef DBG
-#define DBG(x)
-#undef DBGs
-#define DBGs(x)
-
 extern volatile uint32_t Tms;
 
 // inbuf overflow when receiving
-static volatile uint8_t bufovrfl[bTotNumEndpoints] = {0};
+static volatile uint8_t bufovrfl[InterfacesAmount] = {0};
 
 // receive buffer: hold data until chkin() call
-static uint8_t volatile rcvbuf[bTotNumEndpoints][USB_RXBUFSZ];
-static uint8_t volatile rcvbuflen[bTotNumEndpoints] = {0};
+static uint8_t volatile rcvbuf[InterfacesAmount][USB_RXBUFSZ] __attribute__((aligned(4)));
+static uint8_t volatile rcvbuflen[InterfacesAmount] = {0};
 // line coding
 #define DEFLC   {115200, 0, 0, 8}
-static usb_LineCoding lineCoding[bTotNumEndpoints] = {DEFLC, DEFLC, DEFLC};
+static usb_LineCoding lineCoding[InterfacesAmount] = {DEFLC, DEFLC, DEFLC};
 // CDC configured and ready to use
-volatile uint8_t CDCready[bTotNumEndpoints] = {0};
+volatile uint8_t CDCready[InterfacesAmount] = {0};
 
 // ring buffers for incoming and outgoing data
-static uint8_t obuf[bTotNumEndpoints][RBOUTSZ], ibuf[bTotNumEndpoints][RBINSZ];
+static uint8_t obuf[InterfacesAmount][RBOUTSZ], ibuf[InterfacesAmount][RBINSZ];
 #define OBUF(N)  {.data = obuf[N], .length = RBOUTSZ, .head = 0, .tail = 0}
-static volatile ringbuffer rbout[bTotNumEndpoints] = {OBUF(0), OBUF(1), OBUF(2)};
+static volatile ringbuffer rbout[InterfacesAmount] = {OBUF(0), OBUF(1), OBUF(2)};
 #define IBUF(N)  {.data = ibuf[N], .length = RBINSZ, .head = 0, .tail = 0}
-static volatile ringbuffer rbin[bTotNumEndpoints] = {IBUF(0), IBUF(1), IBUF(2)};
+static volatile ringbuffer rbin[InterfacesAmount] = {IBUF(0), IBUF(1), IBUF(2)};
 // last send data size (<0 if USB transfer ready)
-static volatile int lastdsz[bTotNumEndpoints] = {-1, -1, -1};
+static volatile int lastdsz[InterfacesAmount] = {-1, -1, -1};
 
+// check incoming data and set ACK if need
 static void chkin(uint8_t ifno){
-    static int ovrflctr = 0; // "antistall" counter
     if(bufovrfl[ifno]) return; // allow user to know that previous buffer was overflowed and cleared
     if(!rcvbuflen[ifno]) return;
     int w = RB_write((ringbuffer*)&rbin[ifno], (uint8_t*)rcvbuf[ifno], rcvbuflen[ifno]);
-    if(w < 0){ // buffer busy
-        DBG("Can't write into buffer: busy");
+    if(w < 0){
         return;
-    }else if(w == 0){ // no enough space or (WTF) incoming string larger than buffer size
-        if(rcvbuflen[ifno] > rbin[ifno].length || ++ovrflctr > 9999){
-            bufovrfl[ifno] = 1; // real overflow in case if ringbuffer's size less than USB buffer
-            ovrflctr = 0;
-        }else{
-            return; // not enough space
-        }
     }
-    DBG("Put data into buffer");
+    if(w != rcvbuflen[ifno]) bufovrfl[ifno] = 1;
     rcvbuflen[ifno] = 0;
-    uint16_t status = KEEP_DTOG(USB->EPnR[1+ifno]); // don't change DTOG
-    USB->EPnR[1+ifno] = (status & ~(USB_EPnR_STAT_TX|USB_EPnR_CTR_RX)) ^ USB_EPnR_STAT_RX; // prepare to get next data portion
+    uint16_t status = KEEP_DTOG(USB->EPnR[EPNO(ifno)]); // don't change DTOG
+    USB->EPnR[EPNO(ifno)] = (status & ~(USB_EPnR_STAT_TX|USB_EPnR_CTR_RX)) ^ USB_EPnR_STAT_RX; // prepare to get next data portion
 }
 
 // called from transmit EP to send next data portion or by user - when new transmission starts
@@ -100,97 +85,83 @@ static void send_next(uint8_t ifno){
     }
     if(buflen == 0){
         if(lastdsz[ifno] == USB_TXBUFSZ){
-            EP_Write(1+ifno, NULL, 0); // send ZLP after 64 bits packet when nothing more to send
+            EP_Write(EPNO(ifno), NULL, 0); // send ZLP after 64 bits packet when nothing more to send
             lastdsz[ifno] = 0;
         }else lastdsz[ifno] = -1; // OK. User can start sending data
         return;
     }else if(buflen < 0){
-        DBG("Buff busy");
         lastdsz[ifno] = -1;
         return;
     }
-    DBG("Got data in buf");
-    DBGs(uhex2str(buflen));
-    DBGs(uhex2str(ifno));
-    EP_Write(1+ifno, (uint8_t*)usbbuff, buflen);
+    EP_Write(EPNO(ifno), (uint8_t*)usbbuff, buflen);
     lastdsz[ifno] = buflen;
 }
 
 // data IN/OUT handler
 static void rxtx_handler(){
-    uint8_t epno = (USB->ISTR & USB_ISTR_EPID), ifno = epno - 1;
-    DBG("rxtx_handler");
-    DBGs(uhex2str(ifno));
-    if(epno > bTotNumEndpoints){
-        DBG("wrong ifno");
+    uint8_t epno = (USB->ISTR & USB_ISTR_EPID), ifno = IFNO(epno);
+    if(ifno > InterfacesAmount-1){
         return;
     }
     uint16_t epstatus = KEEP_DTOG(USB->EPnR[epno]);
     if(RX_FLAG(epstatus)){ // receive data
-        DBG("Got data");
         if(rcvbuflen[ifno]){
             bufovrfl[ifno] = 1; // lost last data
             rcvbuflen[ifno] = 0;
-            DBG("OVERFULL");
         }
         rcvbuflen[ifno] = EP_Read(epno, (uint8_t*)rcvbuf[ifno]);
-        DBGs(uhex2str(rcvbuflen[ifno]));
         USB->EPnR[epno] = epstatus & ~(USB_EPnR_CTR_RX | USB_EPnR_STAT_RX | USB_EPnR_STAT_TX); // keep RX in STALL state until read data
         chkin(ifno); // try to write current data into RXbuf if it's not busy
     }else{ // tx successfull
-        DBG("Tx OK");
         USB->EPnR[epno] = (epstatus & ~(USB_EPnR_CTR_TX | USB_EPnR_STAT_TX)) ^ USB_EPnR_STAT_RX;
         send_next(ifno);
     }
 }
 
-// weak handlers: change them somewhere else if you want to setup USART
-// SET_LINE_CODING
-void WEAK linecoding_handler(uint8_t ifno, usb_LineCoding *lc){
-    lineCoding[ifno] = *lc;
-    DBG("linecoding_handler");
-    DBGs(uhex2str(ifno));
-}
-
-static void clearbufs(uint8_t ifno){
+static void clearRbuf(uint8_t ifno){
     uint32_t T0 = Tms;
     while(Tms - T0 < 10){ // wait no more than 10ms
         if(1 == RB_clearbuf((ringbuffer*)&rbin[ifno])) break;
     }
-    T0 = Tms;
+}
+
+static void clearTbuf(uint8_t ifno){
+    uint32_t T0 = Tms;
     while(Tms - T0 < 10){
         if(1 == RB_clearbuf((ringbuffer*)&rbout[ifno])) break;
     }
-    rcvbuflen[ifno] = 0;
+}
+
+// SET_LINE_CODING
+void linecoding_handler(uint8_t ifno, usb_LineCoding *lc){
+    lineCoding[ifno] = *lc;
 }
 
 // SET_CONTROL_LINE_STATE
-void WEAK clstate_handler(uint8_t ifno, uint16_t val){
-    DBG("clstate_handler");
-    DBGs(uhex2str(ifno));
-    DBGs(uhex2str(val));
-    if(val) clearbufs(ifno); // clear buffers on connect
+void clstate_handler(uint8_t ifno, uint16_t val){
     CDCready[ifno] = val; // CONTROL_DTR | CONTROL_RTS -> interface connected; 0 -> disconnected
     lastdsz[ifno] = -1;
+    if(val){
+        clearRbuf(ifno);
+        clearTbuf(ifno);
+        EP_reset(EPNO(ifno));
+    }
 }
 
 // SEND_BREAK - disconnect interface and clear its buffers
-void WEAK break_handler(uint8_t ifno){
+// this is a fake handler as classic CDC ACM never receives this
+void break_handler(uint8_t ifno){
     CDCready[ifno] = 0;
-    DBG("break_handler()");
-    DBGs(uhex2str(ifno));
 }
 
-// USB is configured: setup endpoints
+// Interface is configured: setup endpoints
 void set_configuration(){
-    DBG("set_configuration()");
-    for(int i = 0; i < bTotNumEndpoints; ++i){
+    for(int i = 0; i < InterfacesAmount; ++i){
         IWDG->KR = IWDG_REFRESH;
-        int r = EP_Init(1+i, EP_TYPE_BULK, USB_TXBUFSZ, USB_RXBUFSZ, rxtx_handler);
+        int r = EP_Init(EPNO(i), EP_TYPE_BULK, USB_TXBUFSZ, USB_RXBUFSZ, rxtx_handler);
         if(r){
-            DBG("Can't init EP");
-            DBGs(uhex2str(i));
-            DBGs(uhex2str(r));
+            // OOPS, can't init EP. What to do? Cry?
+            break;
         }
     }
 }
@@ -200,45 +171,33 @@ void usb_class_request(config_pack_t *req, uint8_t *data, uint16_t datalen){
     uint8_t recipient = REQUEST_RECIPIENT(req->bmRequestType);
     uint8_t dev2host = (req->bmRequestType & 0x80) ? 1 : 0;
     uint8_t ifno = req->wIndex >> 1;
-    if(ifno > bTotNumEndpoints-1 && ifno != 0xff){
-        DBG("wrong ifno");
+    if(ifno > InterfacesAmount-1){ // wrong interface number
+        EP_WriteIRQ(0, NULL, 0);
         return;
     }
-    DBG("usb_class_request");
-    DBGs(uhex2str(req->bRequest));
     switch(recipient){
-        case REQ_RECIPIENT_INTERFACE:
-            switch(req->bRequest){
-                case SET_LINE_CODING:
-                    DBG("SET_LINE_CODING");
-                    if(!data || !datalen) break; // wait for data
-                    if(datalen == sizeof(usb_LineCoding))
-                        linecoding_handler(ifno, (usb_LineCoding*)data);
-                break;
-                case GET_LINE_CODING:
-                    DBG("GET_LINE_CODING");
-                    EP_WriteIRQ(0, (uint8_t*)&lineCoding[ifno], sizeof(lineCoding));
-                break;
-                case SET_CONTROL_LINE_STATE:
-                    DBG("SET_CONTROL_LINE_STATE");
-                    clstate_handler(ifno, req->wValue);
-                break;
-                case SEND_BREAK:
-                    DBG("SEND_BREAK");
-                    break_handler(ifno);
-                break;
-                default:
-                    DBG("Wrong");
-                    DBGs(uhex2str(req->bRequest));
-                    DBGs(uhex2str(datalen));
-            }
+    case REQ_RECIPIENT_INTERFACE:
+        switch(req->bRequest){
+        case SET_LINE_CODING:
+            if(!data || !datalen) break; // wait for data
+            if(datalen == sizeof(usb_LineCoding))
+                linecoding_handler(ifno, (usb_LineCoding*)data);
+            break;
+        case GET_LINE_CODING:
+            EP_WriteIRQ(0, (uint8_t*)&lineCoding[ifno], sizeof(lineCoding));
+            break;
+        case SET_CONTROL_LINE_STATE:
+            clstate_handler(ifno, req->wValue);
+            break;
+        case SEND_BREAK:
+            break_handler(ifno);
+            break;
+        default: // WTF?
+            break;
+        }
         break;
-        default:
-            DBG("Wrong");
-            DBGs(uhex2str(recipient));
-            DBGs(uhex2str(datalen));
-            DBGs(uhex2str(req->bRequest));
-            if(dev2host) EP_WriteIRQ(0, NULL, 0);
+    default: // WTF?
+        if(dev2host) EP_WriteIRQ(0, NULL, 0);
     }
     if(!dev2host) EP_WriteIRQ(0, NULL, 0);
 }
@@ -248,7 +207,6 @@ int USB_sendall(uint8_t ifno){
     uint32_t T0 = Tms;
     while(lastdsz[ifno] > 0){
         if(Tms - T0 > DISCONN_TMOUT){
-            break_handler(ifno);
             return FALSE;
         }
         if(!CDCready[ifno]) return FALSE;
@@ -257,17 +215,25 @@ int USB_sendall(uint8_t ifno){
     return TRUE;
 }
 
+// return amount of free space in buffer
+int USB_sendbufspace(uint8_t ifno){
+    if(!CDCready[ifno]) return 0;
+    return rbout[ifno].length - RB_datalen((ringbuffer*)&rbout[ifno]);
+}
+
 // put `buf` into queue to send
 int USB_send(uint8_t ifno, const uint8_t *buf, int len){
-    if(!buf || !CDCready[ifno] || !len) return FALSE;
-    DBG("USB_send");
+    if(!buf || !CDCready[ifno] || !len){
+        return FALSE;
+    }
     uint32_t T0 = Tms;
     while(len){
         if(Tms - T0 > DISCONN_TMOUT){
-            break_handler(ifno);
             return FALSE;
         }
-        if(!CDCready[ifno]) return FALSE;
+        if(!CDCready[ifno]){
+            return FALSE;
+        }
         IWDG->KR = IWDG_REFRESH;
         int l = RB_datalen((ringbuffer*)&rbout[ifno]);
         if(l < 0) continue;
@@ -285,7 +251,9 @@ int USB_send(uint8_t ifno, const uint8_t *buf, int len){
             if(lastdsz[ifno] < 0) send_next(ifno);
         }
     }
-    if(buf[len-1] == '\n' && lastdsz[ifno] < 0) send_next(ifno);
+    if(buf[len-1] == '\n' && lastdsz[ifno] < 0){
+        send_next(ifno);
+    }
     return TRUE;
 }
 
@@ -295,7 +263,6 @@ int USB_putbyte(uint8_t ifno, uint8_t byte){
     uint32_t T0 = Tms;
     while((l = RB_write((ringbuffer*)&rbout[ifno], &byte, 1)) != 1){
         if(Tms - T0 > DISCONN_TMOUT){
-            break_handler(ifno);
             return FALSE;
         }
         if(!CDCready[ifno]) return FALSE;
@@ -306,7 +273,9 @@ int USB_putbyte(uint8_t ifno, uint8_t byte){
         }
     }
     // send line if got EOL
-    if(byte == '\n' && lastdsz[ifno] < 0) send_next(ifno);
+    if(byte == '\n' && lastdsz[ifno] < 0){
+        send_next(ifno);
+    }
     return TRUE;
 }
 
@@ -317,6 +286,10 @@ int USB_sendstr(uint8_t ifno, const char *string){
     return USB_send(ifno, (const uint8_t*)string, len);
 }
 
+int USB_rcvlen(uint8_t ifno){
+    return RB_datalen((ringbuffer*)&rbin[ifno]);
+}
+
 /**
  * @brief USB_receive - get binary data from receiving ring-buffer
  * @param buf (i) - buffer for received data
@@ -324,17 +297,15 @@ int USB_sendstr(uint8_t ifno, const char *string){
  * @return amount of received bytes (negative, if overfull happened)
  */
 int USB_receive(uint8_t ifno, uint8_t *buf, int len){
+    if(!CDCready[ifno]) return 0;
     chkin(ifno); // rxtx_handler could leave last message unwritten if buffer was busy
     if(bufovrfl[ifno]){
-        DBG("Buffer overflow");
-        DBGs(uhex2str(ifno));
-        while(1 != RB_clearbuf((ringbuffer*)&rbin[ifno])); // run watchdog in case of problems
+        clearRbuf(ifno);
         bufovrfl[ifno] = 0;
         return -1;
     }
     int sz = RB_read((ringbuffer*)&rbin[ifno], buf, len);
     if(sz < 0) return 0; // buffer in writting state
-    DBG("usb read");
     return sz;
 }
 
@@ -345,24 +316,22 @@ int USB_receive(uint8_t ifno, uint8_t *buf, int len){
  * @return strlen or negative value indicating overflow (if so, string won't be ends with 0 and buffer should be cleared)
  */
 int USB_receivestr(uint8_t ifno, char *buf, int len){
+    if(!CDCready[ifno]) return 0;
     chkin(ifno); // rxtx_handler could leave last message unwritten if buffer was busy
     if(bufovrfl[ifno]){
-        while(1 != RB_clearbuf((ringbuffer*)&rbin[ifno]));
+        clearRbuf(ifno);
         bufovrfl[ifno] = 0;
         return -1;
     }
     int l = RB_readto((ringbuffer*)&rbin[ifno], '\n', (uint8_t*)buf, len);
     if(l < 1){
-        //if(rbin[ifno].length < 1 + RB_datalen((ringbuffer*)&rbin[ifno])){ // buffer is full but no '\n' found
-        if(RB_datalen((ringbuffer*)&rbin[ifno]) >= len){
-            CMDWRn("OVERFULL!");
-            while(1 != RB_clearbuf((ringbuffer*)&rbin[ifno]));
+        if((rbin[ifno].length <= RB_datalen((ringbuffer*)&rbin[ifno]) + 1) ||
+            (RB_datalento((ringbuffer*)&rbin[ifno], '\n') > len - 1)){ // buffer is full but no '\n' found or string too long
+            clearRbuf(ifno);
             return -1;
         }
         return 0;
     }
-    if(l == 0) return 0;
     buf[l-1] = 0; // replace '\n' with strend
     return l;
 }
-
diff --git a/F1:F103/BISS_C_encoders/usb_dev.h b/F1:F103/BISS_C_encoders/usb_dev.h
index 7308630..064f473 100644
--- a/F1:F103/BISS_C_encoders/usb_dev.h
+++ b/F1:F103/BISS_C_encoders/usb_dev.h
@@ -40,14 +40,14 @@ typedef struct {
     uint8_t bDataBits;
 } __attribute__ ((packed)) usb_LineCoding;
 
-extern volatile uint8_t CDCready[bTotNumEndpoints];
+extern volatile uint8_t CDCready[InterfacesAmount];
 
 void break_handler(uint8_t ifno);
 void clstate_handler(uint8_t ifno, uint16_t val);
 void linecoding_handler(uint8_t ifno, usb_LineCoding *lc);
 
 // as ugly CDC have no BREAK after disconnected client in non-canonical mode, we should use timeout - more than 2ms
-#define DISCONN_TMOUT   (1000)
+#define DISCONN_TMOUT   (2)
 
 // sizes of ringbuffers for outgoing and incoming data
 #define RBOUTSZ     (512)
@@ -69,9 +69,11 @@ void linecoding_handler(uint8_t ifno, usb_LineCoding *lc);
 #define DBGs(s)
 #endif
 
+int USB_sendbufspace(uint8_t ifno);
 int USB_sendall(uint8_t ifno);
 int USB_send(uint8_t ifno, const uint8_t *buf, int len);
 int USB_putbyte(uint8_t ifno, uint8_t byte);
 int USB_sendstr(uint8_t ifno, const char *string);
+int USB_rcvlen(uint8_t ifno);
 int USB_receive(uint8_t ifno, uint8_t *buf, int len);
 int USB_receivestr(uint8_t ifno, char *buf, int len);
diff --git a/F1:F103/BISS_C_encoders/usb_lib.c b/F1:F103/BISS_C_encoders/usb_lib.c
index 2779402..8ed4e0e 100644
--- a/F1:F103/BISS_C_encoders/usb_lib.c
+++ b/F1:F103/BISS_C_encoders/usb_lib.c
@@ -20,15 +20,10 @@
 #include "usb_descr.h"
 #include "usb_dev.h"
 
-#undef DBG
-#define DBG(x)
-#undef DBGs
-#define DBGs(x)
-
 static ep_t endpoints[STM32ENDPOINTS];
 
 static uint16_t USB_Addr = 0;
-static uint8_t setupdatabuf[EP0DATABUF_SIZE];
+static uint8_t setupdatabuf[EP0DATABUF_SIZE] __attribute__((aligned(4)));
 static config_pack_t *setup_packet = (config_pack_t*) setupdatabuf;
 volatile uint8_t usbON = 0; // device is configured and active
 
@@ -37,20 +32,15 @@ static inline void std_d2h_req(){
     uint16_t st = 0;
     switch(setup_packet->bRequest){
         case GET_DESCRIPTOR:
-            DBG("GET_DESCRIPTOR");
             get_descriptor(setup_packet);
         break;
         case GET_STATUS:
-            DBG("GET_STATUS");
             EP_WriteIRQ(0, (uint8_t *)&st, 2); // send status: Bus Powered
         break;
         case GET_CONFIGURATION:
-            DBG("GET_CONFIGURATION");
             EP_WriteIRQ(0, (uint8_t*)&configuration, 1);
         break;
         default:
-            DBG("Wrong");
-            DBGs(uhex2str(setup_packet->bRequest));
             EP_WriteIRQ(0, NULL, 0);
         break;
     }
@@ -59,21 +49,16 @@ static inline void std_d2h_req(){
 static inline void std_h2d_req(){
     switch(setup_packet->bRequest){
         case SET_ADDRESS:
-            DBG("SET_ADDRESS");
             // new address will be assigned later - after  acknowlegement or request to host
             USB_Addr = setup_packet->wValue;
-            DBGs(uhex2str(USB_Addr));
         break;
         case SET_CONFIGURATION:
-            DBG("SET_CONFIGURATION");
             // Now device configured
             configuration = setup_packet->wValue;
             set_configuration();
             usbON = 1;
         break;
         default:
-            DBG("Wrong");
-            DBGs(uhex2str(setup_packet->bRequest));
         break;
     }
 }
@@ -83,7 +68,6 @@ void WEAK usb_standard_request(){
     uint8_t dev2host = (setup_packet->bmRequestType & 0x80) ? 1 : 0;
     switch(recipient){
         case REQ_RECIPIENT_DEVICE:
-            DBG("REQ_RECIPIENT_DEVICE");
             if(dev2host){
                 std_d2h_req();
             }else{
@@ -91,49 +75,34 @@ void WEAK usb_standard_request(){
             }
         break;
         case REQ_RECIPIENT_INTERFACE:
-            DBG("REQ_RECIPIENT_INTERFACE");
             if(dev2host && setup_packet->bRequest == GET_DESCRIPTOR){
                 get_descriptor(setup_packet);
             }
         break;
         case REQ_RECIPIENT_ENDPOINT:
-            DBG("REQ_RECIPIENT_ENDPOINT");
             if(setup_packet->bRequest == CLEAR_FEATURE){
-            }else{
-                DBG("Wrong");
-            }
+            }else{ /* wrong */ }
         break;
         default:
-            DBG("Wrong");
-            DBGs(uhex2str(recipient));
         break;
     }
     if(!dev2host) EP_WriteIRQ(0, NULL, 0);
 }
 
 void WEAK usb_class_request(config_pack_t *req, uint8_t _U_ *data, uint16_t _U_ datalen){
-    DBG("REQ_TYPE_CLASS");
     switch(req->bRequest){
         case GET_INTERFACE:
-            DBG("GI");
         break;
         case SET_CONFIGURATION: // set featuring by req->wValue
-            DBG("SC");
         break;
         default:
-            DBG("Wrong");
-            DBGs(uhex2str(req->bmRequestType));
-            DBGs(uhex2str(req->bRequest));
-            DBGs(uhex2str(req->wIndex));
-            DBGs(uhex2str(req->wLength));
-            DBGs(uhex2str(req->wValue));
+            break;
     }
     if(0 == (setup_packet->bmRequestType & 0x80)) // host2dev
         EP_WriteIRQ(0, NULL, 0);
 }
 
 void WEAK usb_vendor_request(config_pack_t _U_ *packet, uint8_t _U_ *data, uint16_t _U_ datalen){
-    DBG("vendor");
     if(0 == (setup_packet->bmRequestType & 0x80)) // host2dev
         EP_WriteIRQ(0, NULL, 0);
 }
@@ -149,18 +118,16 @@ bmRequestType: 76543210
  */
 static void EP0_Handler(){
     uint8_t ep0dbuflen = 0;
-    uint8_t ep0databuf[EP0DATABUF_SIZE];
+    uint8_t ep0databuf[EP0DATABUF_SIZE] __attribute__((aligned(4)));
     uint16_t epstatus = KEEP_DTOG(USB->EPnR[0]); // EP0R on input -> return this value after modifications
     int rxflag = RX_FLAG(epstatus);
-    if(rxflag){ DBG("EP0_Handler"); }
     // check direction
     if(USB->ISTR & USB_ISTR_DIR){ // OUT interrupt - receive data, CTR_RX==1 (if CTR_TX == 1 - two pending transactions: receive following by transmit)
             if(epstatus & USB_EPnR_SETUP){ // setup packet -> copy data to conf_pack
-                DBG("USB_EPnR_SETUP");
                 EP_Read(0, setupdatabuf);
                 // interrupt handler will be called later
             }else if(epstatus & USB_EPnR_CTR_RX){ // data packet -> push received data to ep0databuf
-                if(endpoints[0].rx_cnt){ DBG("data"); DBGs(uhex2str(endpoints[0].rx_cnt));}
+                //if(endpoints[0].rx_cnt){ }
                 ep0dbuflen = EP_Read(0, ep0databuf);
             }
     }
@@ -169,23 +136,16 @@ static void EP0_Handler(){
         switch(reqtype){
             case REQ_TYPE_STANDARD:
                 if(SETUP_FLAG(epstatus)){
-                    DBG("REQ_TYPE_STANDARD");
                     usb_standard_request();
-                }else{
-                    DBG("REQ_TYPE_STANDARD without SETUP_FLAG");
-                }
+                }else{ }
                 break;
             case REQ_TYPE_CLASS:
-                DBG("REQ_TYPE_CLASS");
                 usb_class_request(setup_packet, ep0databuf, ep0dbuflen);
                 break;
             case REQ_TYPE_VENDOR:
-                DBG("REQ_TYPE_VENDOR");
                 usb_vendor_request(setup_packet, ep0databuf, ep0dbuflen);
                 break;
             default:
-                DBG("Wrong");
-                DBGs(uhex2str(reqtype));
                 EP_WriteIRQ(0, NULL, 0);
                 break;
         }
@@ -195,8 +155,6 @@ static void EP0_Handler(){
         if ((USB->DADDR & USB_DADDR_ADD) != USB_Addr){
             USB->DADDR = USB_DADDR_EF | USB_Addr;
             usbON = 0;
-            DBG("Enum");
-            DBGs(uhex2str(USB_Addr));
         }
     }
     //epstatus = KEEP_DTOG(USB->EPnR[0]);
@@ -214,9 +172,14 @@ static void EP0_Handler(){
  */
 void EP_WriteIRQ(uint8_t number, const uint8_t *buf, uint16_t size){
     if(size > endpoints[number].txbufsz) size = endpoints[number].txbufsz;
+#ifndef USB32
     uint16_t N2 = (size + 1) >> 1;
     // the buffer is 16-bit, so we should copy data as it would be uint16_t
     uint16_t *buf16 = (uint16_t *)buf;
+#else
+    int N4 = (size + 3) >> 2;
+    uint32_t *buf32 = (uint32_t *)buf;
+#endif
 #if defined USB1_16
     // very bad: what if `size` is odd?
     uint32_t *out = (uint32_t *)endpoints[number].tx_buf;
@@ -225,13 +188,19 @@ void EP_WriteIRQ(uint8_t number, const uint8_t *buf, uint16_t size){
     }
 #elif defined USB2_16
     // use memcpy instead?
-    for(int i = 0; i < N2; i++){
+    for(int i = 0; i < N2; ++i){
         endpoints[number].tx_buf[i] = buf16[i];
     }
+#elif defined USB32
+    for(int i = 0; i < N4; ++i) endpoints[number].tx_buf[i] = buf32[i];
 #else
-#error "Define USB1_16 or USB2_16"
+#error "Define USB1_16 / USB2_16 / USB32"
 #endif
+#ifndef USB32
     USB_BTABLE->EP[number].USB_COUNT_TX = size;
+#else
+    USB_BTABLE->EP[number].USB_ADDR_COUNT_TX = (USB_BTABLE->EP[number].USB_ADDR_COUNT_TX & 0xffff) | (size << 16);
+#endif
 }
 
 /**
@@ -266,8 +235,12 @@ int EP_Read(uint8_t number, uint8_t *buf){
     // use memcpy instead?
     for(int i = 0; i < sz; ++i)
         buf[i] = endpoints[number].rx_buf[i];
+#elif defined USB32
+    uint32_t *u32buf = (uint32_t*) buf;
+    int N4 = (sz + 3) >> 2;
+    for(int i = 0; i < N4; ++i) u32buf[i] = endpoints[number].rx_buf[i];
 #else
-#error "Define USB1_16 or USB2_16"
+#error "Define USB1_16 / USB2_16 / USB32"
 #endif
     return sz;
 }
@@ -284,11 +257,16 @@ static uint16_t lastaddr = LASTADDR_DEFAULT;
  * @return 0 if all OK
  */
 int EP_Init(uint8_t number, uint8_t type, uint16_t txsz, uint16_t rxsz, void (*func)(ep_t ep)){
+#ifdef STM32G0
+    // in STM32G0 all buffers should be aligned by 32 bits
+    if(txsz & 3) txsz = ((txsz >> 2)+1) << 2;
+    if(rxsz & 3) rxsz = ((rxsz >> 2)+1) << 2;
+#endif
     if(number >= STM32ENDPOINTS) return 4; // out of configured amount
     if(txsz > USB_BTABLE_SIZE/ACCESSZ || rxsz > USB_BTABLE_SIZE/ACCESSZ) return 1; // buffer too large
     if(lastaddr + txsz + rxsz >= USB_BTABLE_SIZE/ACCESSZ) return 2; // out of btable
     USB->EPnR[number] = (type << 9) | (number & USB_EPnR_EA);
-    USB->EPnR[number] ^= USB_EPnR_STAT_RX | USB_EPnR_STAT_TX_1;
+    USB->EPnR[number] ^= USB_EPnR_STAT_RX | USB_EPnR_STAT_TX;
     if(rxsz & 1) return 3; // wrong rx buffer size
     uint16_t countrx = 0;
     if(rxsz < 64) countrx = rxsz / 2;
@@ -296,25 +274,49 @@ int EP_Init(uint8_t number, uint8_t type, uint16_t txsz, uint16_t rxsz, void (*f
         if(rxsz & 0x1f) return 3; // should be multiple of 32
         countrx = 31 + rxsz / 32;
     }
-    USB_BTABLE->EP[number].USB_ADDR_TX = lastaddr;
+#ifdef USB32
+    endpoints[number].tx_buf = (uint32_t *)(USB_BTABLE_BASE + lastaddr * ACCESSZ);
+#else
     endpoints[number].tx_buf = (uint16_t *)(USB_BTABLE_BASE + lastaddr * ACCESSZ);
+#endif
     endpoints[number].txbufsz = txsz;
-    lastaddr += txsz;
+#ifdef USB32
+    USB_BTABLE->EP[number].USB_ADDR_COUNT_TX = (uint32_t) lastaddr;
+#else
+    USB_BTABLE->EP[number].USB_ADDR_TX = lastaddr;
     USB_BTABLE->EP[number].USB_COUNT_TX = 0;
-    USB_BTABLE->EP[number].USB_ADDR_RX = lastaddr;
+#endif
+    lastaddr += txsz;
+#ifdef USB32
+    endpoints[number].rx_buf = (uint32_t *)(USB_BTABLE_BASE + lastaddr * ACCESSZ);
+    USB_BTABLE->EP[number].USB_ADDR_COUNT_RX = (uint32_t) lastaddr | countrx << 26;
+#else
     endpoints[number].rx_buf = (uint8_t *)(USB_BTABLE_BASE + lastaddr * ACCESSZ);
-    lastaddr += rxsz;
+    USB_BTABLE->EP[number].USB_ADDR_RX = lastaddr;
     USB_BTABLE->EP[number].USB_COUNT_RX = countrx << 10;
+#endif
+    lastaddr += rxsz;
     endpoints[number].func = func;
     return 0;
 }
 
+// refresh EP after interface reconnected
+void EP_reset(uint8_t epno){
+    if(epno >= STM32ENDPOINTS) return;
+    // keep DTOGs (don't write 1 to them), clear CTR (write 0 to them)
+    //      and set STAT to VALID (write 1 where was 0)
+    uint16_t epstatus = KEEP_DTOG(USB->EPnR[epno]);
+    USB->EPnR[epno] = (epstatus & ~(USB_EPnR_CTR_TX|USB_EPnR_CTR_RX)) ^
+                        (USB_EPnR_STAT_RX | USB_EPnR_STAT_TX);
+    USB_BTABLE->EP[epno].USB_COUNT_TX = 0;
+}
+
 // standard IRQ handler
 void USB_IRQ(){
     uint32_t CNTR = USB->CNTR;
     USB->CNTR = 0;
-    if(USB->ISTR & USB_ISTR_RESET){
-        DBG("USB_ISTR_RESET");
+    uint32_t istr = USB->ISTR;
+    if(istr & USB_ISTR_RESET){
         usbON = 0;
         // Reinit registers
         CNTR = USB_CNTR_RESETM | USB_CNTR_CTRM | USB_CNTR_SUSPM;
@@ -323,45 +325,56 @@ void USB_IRQ(){
         lastaddr = LASTADDR_DEFAULT;
         // clear address, leave only enable bit
         USB->DADDR = USB_DADDR_EF;
-        USB->ISTR = ~USB_ISTR_RESET;
+        //USB->ISTR = ~(USB_ISTR_RESET); // clear all flags
         if(EP_Init(0, EP_TYPE_CONTROL, USB_EP0BUFSZ, USB_EP0BUFSZ, EP0_Handler)){
-            DBG("Can't init EP0");
             return;
         };
     }
-    if(USB->ISTR & USB_ISTR_CTR){
+    if(istr & USB_ISTR_CTR){
         // EP number
-        uint8_t n = USB->ISTR & USB_ISTR_EPID;
+        uint8_t n = istr & USB_ISTR_EPID;
+        if (istr & USB_ISTR_DIR){ // OUT
+        }else{ // IN
+        }
         // copy received bytes amount
-        endpoints[n].rx_cnt = USB_BTABLE->EP[n].USB_COUNT_RX & 0x3FF; // low 10 bits is counter
+        endpoints[n].rx_cnt =
+#ifdef USB32
+            (USB_BTABLE->EP[n].USB_ADDR_COUNT_RX >> 16) & 0x3FF;
+#else
+        USB_BTABLE->EP[n].USB_COUNT_RX & 0x3FF; // low 10 bits is counter
+#endif
         // call EP handler
         if(endpoints[n].func) endpoints[n].func();
     }
-    if(USB->ISTR & USB_ISTR_WKUP){ // wakeup
-        DBG("USB_ISTR_WKUP");
-#ifndef STM32F0
-        CNTR &= ~(USB_CNTR_FSUSP | USB_CNTR_LP_MODE | USB_CNTR_WKUPM); // clear suspend flags
-#else
+    if(istr & USB_ISTR_WKUP){ // wakeup
+#if defined STM32F0
         CNTR &= ~(USB_CNTR_FSUSP | USB_CNTR_LPMODE | USB_CNTR_WKUPM);
-#endif
-        USB->ISTR = ~USB_ISTR_WKUP;
-    }
-    if(USB->ISTR & USB_ISTR_SUSP){ // suspend -> still no connection, may sleep
-        DBG("USB_ISTR_SUSP");
-        usbON = 0;
-#ifndef STM32F0
-        CNTR |= USB_CNTR_FSUSP | USB_CNTR_LP_MODE | USB_CNTR_WKUPM;
+#elif defined STM32G0
+        CNTR &= ~(USB_CNTR_SUSPEN | USB_CNTR_PDWN | USB_CNTR_WKUPM);
 #else
+        CNTR &= ~(USB_CNTR_FSUSP | USB_CNTR_LP_MODE | USB_CNTR_WKUPM); // clear suspend flags
+#endif
+        //USB->ISTR = ~USB_ISTR_WKUP;
+    }
+    if(istr & USB_ISTR_SUSP){ // suspend -> still no connection, may sleep
+        usbON = 0;
+#if defined STM32F0
         CNTR |= USB_CNTR_FSUSP | USB_CNTR_LPMODE | USB_CNTR_WKUPM;
+#elif defined STM32G0
+        CNTR |= USB_CNTR_SUSPEN | USB_CNTR_WKUPM;
+#else
+        CNTR |= USB_CNTR_FSUSP | USB_CNTR_LP_MODE | USB_CNTR_WKUPM;
 #endif
         CNTR &= ~(USB_CNTR_SUSPM);
-        USB->ISTR = ~USB_ISTR_SUSP;
+        //USB->ISTR = ~USB_ISTR_SUSP;
     }
+    USB->ISTR = 0; // clear all flags
     USB->CNTR = CNTR; // rewoke interrupts
 }
 
 // here we suppose that all PIN settings done in hw_setup earlier
 void USB_setup(){
+    lastaddr = LASTADDR_DEFAULT; // clear last address settings
 #if defined STM32F3
     NVIC_DisableIRQ(USB_LP_IRQn);
     // remap USB LP & Wakeup interrupts to 75 and 76 - works only on pure F303
@@ -371,6 +384,7 @@ void USB_setup(){
     NVIC_DisableIRQ(USB_LP_CAN1_RX0_IRQn);
     NVIC_DisableIRQ(USB_HP_CAN1_TX_IRQn);
 #elif defined STM32F0
+    // All is clocking from HSI48
     NVIC_DisableIRQ(USB_IRQn);
     RCC->APB1ENR |= RCC_APB1ENR_CRSEN;
     RCC->CFGR3 &= ~RCC_CFGR3_USBSW; // reset USB
@@ -383,16 +397,33 @@ void USB_setup(){
     CRS->CR |= CRS_CR_AUTOTRIMEN; // enable auto trim
     CRS->CR |= CRS_CR_CEN; // enable freq counter & block CRS->CFGR as read-only
     RCC->CFGR |= RCC_CFGR_SW;
+#elif defined STM32G0
+    NVIC_DisableIRQ(USB_UCPD1_2_IRQn);
+    PWR->CR2 |= PWR_CR2_USV; // enable USB powering
+    //RCC->APBENR2 |= RCC_APBENR2_SYSCFGEN; // enable tacting of SYSCFG
+    // independent clocking of USB from HSI48
+    RCC->CR |= RCC_CR_HSI48ON;
+    uint32_t tmout = 16000000;
+    while(!(RCC->CR & RCC_CR_HSI48RDY)) if(--tmout == 0) break;
+    RCC->CCIPR2 &= ~RCC_CCIPR2_USBSEL; // select HSI48 for USB
+    RCC->APBENR1 |= RCC_APBENR1_CRSEN; // CRS clocking
+    CRS->CFGR = (31LL << CRS_CFGR_FELIM_Pos) | // tolerance (usually 31)
+                (48000LL / 1LL - 1LL) << CRS_CFGR_RELOAD_Pos | // 48MHz / 1kHZ (SOF)
+                CRS_CFGR_SYNCSRC_1; // USB SOF as sync source (0x2)
+    CRS->CR |= CRS_CR_AUTOTRIMEN | CRS_CR_CEN; // Enable autotrim and turn on Clock Recovery System
+    RCC->APBENR1 |= RCC_APBENR1_USBEN;
 #endif
+#ifndef STM32G0
     RCC->APB1ENR |= RCC_APB1ENR_USBEN;
-    //??
     USB->CNTR   = USB_CNTR_FRES; // Force USB Reset
-    for(uint32_t ctr = 0; ctr < 72000; ++ctr) nop(); // wait >1ms
-    USB->CNTR   = 0;
     USB->BTABLE = 0;
+#else
+    USB->CNTR   = USB_CNTR_USBRST;
+#endif
+    for(uint32_t ctr = 0; ctr < 72000; ++ctr) nop(); // wait >1ms
+    USB->CNTR   = USB_CNTR_RESETM; // allow only reset interrupts
     USB->DADDR  = 0;
     USB->ISTR   = 0;
-    USB->CNTR   = USB_CNTR_RESETM; // allow only reset interrupts
 #if defined STM32F3
     NVIC_EnableIRQ(USB_LP_IRQn);
 #elif defined STM32F1
@@ -400,8 +431,11 @@ void USB_setup(){
 #elif defined STM32F0
     USB->BCDR |= USB_BCDR_DPPU;
     NVIC_EnableIRQ(USB_IRQn);
+#elif defined STM32G0
+    USB->BCDR |= USB_BCDR_DPPU; // turn ON DP pullup
+    NVIC_EnableIRQ(USB_UCPD1_2_IRQn);
 #endif
-    setup_interfaces();
+    setup_interfaces(); // refresh interfaces' names
 }
 
 
@@ -411,4 +445,6 @@ void usb_lp_isr() __attribute__ ((alias ("USB_IRQ")));
 void usb_lp_can_rx0_isr() __attribute__ ((alias ("USB_IRQ")));
 #elif defined STM32F0
 void usb_isr() __attribute__ ((alias ("USB_IRQ")));
+#elif defined STM32G0
+void usb_ucpd1_2_isr() __attribute__ ((alias ("USB_IRQ")));
 #endif
diff --git a/F1:F103/BISS_C_encoders/usb_lib.h b/F1:F103/BISS_C_encoders/usb_lib.h
index c6e70b0..1dfb3a8 100644
--- a/F1:F103/BISS_C_encoders/usb_lib.h
+++ b/F1:F103/BISS_C_encoders/usb_lib.h
@@ -19,6 +19,10 @@
 #include <stdint.h>
 #include <wchar.h>
 
+#ifndef _U_
+#define _U_         __attribute__((unused))
+#endif
+
 /******************************************************************
  *             Hardware registers etc                             *
  *****************************************************************/
@@ -30,6 +34,8 @@
 #define USB_BASE                ((uint32_t)0x40005C00)
 #elif defined STM32F3
 #include <stm32f3.h>
+#elif defined STM32G0
+#include <stm32g0.h>
 #endif
 
 // max endpoints number
@@ -38,14 +44,16 @@
  *                 Buffers size definition
  **/
 
-//  F0 - USB2_16; F1 - USB1_16; F3 - 1/2 depending on series
-#if !defined USB1_16 && !defined USB2_16
+//  F0 - USB2_16; F1 - USB1_16; F3 - 1/2 depending on series; G0 - USB32
+#if !defined USB1_16 && !defined USB2_16 && !defined USB32
 #if defined STM32F0
 #define USB2_16
 #elif defined STM32F1
 #define USB1_16
+#elif defined STM32G0
+#define USB32
 #else
-#error "Can't determine USB1_16 or USB2_16, define by hands"
+#error "Can't determine USB1_16/USB2_16/USB32, define by hands"
 #endif
 #endif
 
@@ -59,8 +67,8 @@
 #if defined STM32F0
 #define USB_BTABLE_SIZE         1024
 #elif defined STM32F3
-#define USB_BTABLE_SIZE         512
-#warning "Please, check real buffer size due to docs"
+#define USB_BTABLE_SIZE         1024
+//#warning "Please, check real buffer size due to docs"
 #else
 #error "define STM32F0 or STM32F3"
 #endif
@@ -68,16 +76,21 @@
 #if defined STM32F0
 #define USB_BTABLE_SIZE         768
 #elif defined STM32F3
-#define USB_BTABLE_SIZE         512
-#warning "Please, check real buffer size due to docs"
+#define USB_BTABLE_SIZE         768
+#elif defined STM32G0
+#define USB_BTABLE_SIZE         2048
+//#warning "Please, check real buffer size due to docs"
 #else // STM32F103: 1024 bytes but with 32-bit addressing
 #define USB_BTABLE_SIZE         1024
 #endif
 #endif // NOCAN
 
 // first 64 bytes of USB_BTABLE are registers!
-
+#ifndef STM32G0
 #define USB_BTABLE_BASE         0x40006000
+#else
+#define USB_BTABLE_BASE         0x40009800
+#endif
 #define USB                     ((USB_TypeDef *) USB_BASE)
 
 #ifdef USB_BTABLE
@@ -120,8 +133,12 @@ typedef struct {
     __IO uint32_t ISTR;
     __IO uint32_t FNR;
     __IO uint32_t DADDR;
+#ifndef USB32
     __IO uint32_t BTABLE;
-#ifdef STM32F0
+#else
+    __IO uint32_t RESERVED1; // there's no BTABLE register in STM32G0
+#endif
+#if defined STM32F0 || defined USB32
     __IO uint32_t LPMCSR;
     __IO uint32_t BCDR;
 #endif
@@ -135,16 +152,19 @@ typedef struct{
     __IO uint16_t USB_ADDR_RX;
     __IO uint16_t USB_COUNT_RX;
 #define ACCESSZ (1)
-#define BUFTYPE uint8_t
 #elif defined USB1_16
     __IO uint32_t USB_ADDR_TX;
     __IO uint32_t USB_COUNT_TX;
     __IO uint32_t USB_ADDR_RX;
     __IO uint32_t USB_COUNT_RX;
 #define ACCESSZ (2)
-#define BUFTYPE uint16_t
+#elif defined USB32
+    // 32-bit registers: addr & count in one!
+    __IO uint32_t USB_ADDR_COUNT_TX;
+    __IO uint32_t USB_ADDR_COUNT_RX;
+#define ACCESSZ (1)
 #else
-#error "Define USB1_16 or USB2_16"
+#error "Define USB1_16 (16 bits over 32bit register), USB2_16 (16 bits over 16 bit register) or USB32 (32 bist over 32 bit register)"
 #endif
 } USB_EPDATA_TypeDef;
 
@@ -303,9 +323,17 @@ typedef struct {
 
 // endpoints state
 typedef struct{
+#ifdef USB32
+    uint32_t *tx_buf;           // transmission buffer address
+#else
     uint16_t *tx_buf;           // transmission buffer address
+#endif
     uint16_t txbufsz;           // transmission buffer size
+#ifdef USB32
+    uint32_t *rx_buf;            // reception buffer address
+#else
     uint8_t *rx_buf;            // reception buffer address
+#endif
     void (*func)();             // endpoint action function
     unsigned rx_cnt  : 10;      // received data counter
 } ep_t;
@@ -317,6 +345,7 @@ int EP_Init(uint8_t number, uint8_t type, uint16_t txsz, uint16_t rxsz, void (*f
 void EP_WriteIRQ(uint8_t number, const uint8_t *buf, uint16_t size);
 void EP_Write(uint8_t number, const uint8_t *buf, uint16_t size);
 int EP_Read(uint8_t number, uint8_t *buf);
+void EP_reset(uint8_t epno);
 
 // could be [re]defined in usb_dev.c
 extern void usb_class_request(config_pack_t *packet, uint8_t *data, uint16_t datalen);
diff --git a/F1:F103/BISS_C_encoders/version.inc b/F1:F103/BISS_C_encoders/version.inc
index ebc3fa9..b4b67d4 100644
--- a/F1:F103/BISS_C_encoders/version.inc
+++ b/F1:F103/BISS_C_encoders/version.inc
@@ -1,2 +1,2 @@
-#define BUILD_NUMBER "144"
-#define BUILD_DATE "2026-02-13"
+#define BUILD_NUMBER "147"
+#define BUILD_DATE "2026-03-23"