diff --git a/F0-nolib/3steppersLB/can.c b/F0-nolib/3steppersLB/can.c
index d506da3..e52f899 100644
--- a/F0-nolib/3steppersLB/can.c
+++ b/F0-nolib/3steppersLB/can.c
@@ -203,7 +203,7 @@ CAN_status can_send(uint8_t *msg, uint8_t len, uint16_t target_id){
         return CAN_BUSY;
     }
 #ifdef EBUG
-    DBG("Send data. Len="); printu(len);
+    DBG("Send data"); SEND("Len="); printu(len);
     SEND(", tagid="); printuhex(target_id);
     SEND(", data=");
     for(int i = 0; i < len; ++i){
@@ -254,6 +254,10 @@ static void can_process_fifo(uint8_t fifo_num){
         // CAN_RDTxR: (16-31) - timestamp, (8-15) - filter match index, (0-3) - data length
         CAN_message msg;
         uint8_t *dat = msg.data;
+        { // set all data to 0
+            uint32_t *dptr = (uint32_t*)msg.data;
+            dptr[0] = dptr[1] = 0;
+        }
         uint8_t len = box->RDTR & 0x0f;
         msg.length = len;
         msg.ID = box->RIR >> 21;
@@ -287,7 +291,7 @@ static void can_process_fifo(uint8_t fifo_num){
                     dat[0] = lb & 0xff;
             }
         }
-        if(msg.ID == OUTPID) parseCANcommand(&msg);
+        if(msg.ID == the_conf.CANID) parseCANcommand(&msg);
         if(CAN_messagebuf_push(&msg)) return; // error: buffer is full, try later
         *RFxR |= CAN_RF0R_RFOM0; // release fifo for access to next message
     }
@@ -313,14 +317,17 @@ TRUE_INLINE void parseCANcommand(CAN_message *msg){
     int N = 1000;
     // we don't check msg here as it cannot be NULL
 #ifdef EBUG
-    SEND("Get data: ");
+    DBG("Get data");
     for(int i = 0; i < msg->length; ++i){
         printuhex(msg->data[i]); bufputchar(' ');
     }
-    NL();
+    newline();
 #endif
     if(msg->length == 0) goto sendmessage; // PING
     uint16_t Index = *(uint16_t*)msg->data;
+#ifdef EBUG
+    SEND("Index = "); printu(Index); newline();
+#endif
     if(Index >= CMD_AMOUNT){
         formerr(msg, ERR_BADCMD);
         goto sendmessage;
@@ -338,12 +345,17 @@ TRUE_INLINE void parseCANcommand(CAN_message *msg){
         formerr(msg, ERR_WRONGLEN);
         goto sendmessage;
     }
+#ifdef EBUG
+    SEND("Run command\n");
+#endif
     errcodes ec = cmdlist[Index](par, val);
     if(ec != ERR_OK){
         formerr(msg, ec);
+    }else{
+        msg->length = 8;
     }
 sendmessage:
-    while(CAN_BUSY == can_send(msg->data, msg->length, OUTPID))
+    while(CAN_BUSY == can_send(msg->data, msg->length, the_conf.CANID))
         if(--N == 0) break;
 }
 
diff --git a/F0-nolib/3steppersLB/can.h b/F0-nolib/3steppersLB/can.h
index af9724e..ced8329 100644
--- a/F0-nolib/3steppersLB/can.h
+++ b/F0-nolib/3steppersLB/can.h
@@ -23,9 +23,6 @@
 #include "flash.h"
 #include "hardware.h"
 
-// output messages identifier
-#define OUTPID  (the_conf.CANID)
-
 // CAN ID mask (11 bits)
 #define CANIDMASK           (0x7ff)
 
diff --git a/F0-nolib/3steppersLB/commonproto.h b/F0-nolib/3steppersLB/commonproto.h
index efb5756..07e1c26 100644
--- a/F0-nolib/3steppersLB/commonproto.h
+++ b/F0-nolib/3steppersLB/commonproto.h
@@ -37,12 +37,12 @@
 
 // error codes for answer message
 typedef enum{
-    ERR_OK,         // all OK
-    ERR_BADPAR,     // parameter's value is wrong
-    ERR_BADVAL,     // wrong parameter's value
-    ERR_WRONGLEN,   // wrong message length
-    ERR_BADCMD,     // unknown command
-    ERR_CANTRUN,    // can't run given command due to bad parameters or other
+    ERR_OK,         // 0 - all OK
+    ERR_BADPAR,     // 1 - parameter's value is wrong
+    ERR_BADVAL,     // 2 - wrong parameter's value
+    ERR_WRONGLEN,   // 3 - wrong message length
+    ERR_BADCMD,     // 4 - unknown command
+    ERR_CANTRUN,    // 5 - can't run given command due to bad parameters or other
 } errcodes;
 
 // pointer to function for command execution, both should be non-NULL for common cases
diff --git a/F0-nolib/3steppersLB/flash.h b/F0-nolib/3steppersLB/flash.h
index a557426..5794a20 100644
--- a/F0-nolib/3steppersLB/flash.h
+++ b/F0-nolib/3steppersLB/flash.h
@@ -50,7 +50,7 @@ typedef struct{
     uint8_t encreverse : 1;     // bit1 - reversing encoder rotation TODO: configure encoder's timer to downcounting
     uint8_t haveencoder : 1;    // bit2 - have encoder
     uint8_t donthold : 1;       // bit3 - clear power @ stop (don't hold motor when stopped)
-    uint8_t eswinv : 1;         // bit4 - invers end-switches
+    uint8_t eswinv : 1;         // bit4 - inverse end-switches
     uint8_t keeppos : 1;        // bit5 - keep current position (as servo motor)
 } motflags_t;
 
diff --git a/F0-nolib/3steppersLB/main.c b/F0-nolib/3steppersLB/main.c
index ee016ff..9ac0c20 100644
--- a/F0-nolib/3steppersLB/main.c
+++ b/F0-nolib/3steppersLB/main.c
@@ -77,7 +77,7 @@ int main(void){
     flashstorage_init(); // should be called before any other functions
     gpio_setup();
     USB_setup();
-    CAN_setup(DEFAULT_CAN_SPEED);
+    CAN_setup(the_conf.CANspeed);
     adc_setup();
     init_steppers();
     RCC->CSR |= RCC_CSR_RMVF; // remove reset flags
@@ -102,19 +102,17 @@ int main(void){
         process_steppers();
         IWDG->KR = IWDG_REFRESH;
         while((can_mesg = CAN_messagebuf_pop())){
-            if(can_mesg && isgood(can_mesg->ID)){
-                if(ShowMsgs){ // new data in buff
-                    IWDG->KR = IWDG_REFRESH;
-                    len = can_mesg->length;
-                    printu(Tms);
-                    SEND(" #");
-                    printuhex(can_mesg->ID);
-                    for(ctr = 0; ctr < len; ++ctr){
-                        SEND(" ");
-                        printuhex(can_mesg->data[ctr]);
-                    }
-                    newline(); sendbuf();
+            if(can_mesg && ShowMsgs && isgood(can_mesg->ID)){
+                IWDG->KR = IWDG_REFRESH;
+                len = can_mesg->length;
+                printu(Tms);
+                SEND(" #");
+                printuhex(can_mesg->ID);
+                for(ctr = 0; ctr < len; ++ctr){
+                    SEND(" ");
+                    printuhex(can_mesg->data[ctr]);
                 }
+                newline(); sendbuf();
             }
         }
         IWDG->KR = IWDG_REFRESH;
diff --git a/F0-nolib/3steppersLB/steppers.bin b/F0-nolib/3steppersLB/steppers.bin
index b5dbaae..0aaace9 100755
Binary files a/F0-nolib/3steppersLB/steppers.bin and b/F0-nolib/3steppersLB/steppers.bin differ
diff --git a/F0-nolib/3steppersLB/strfunct.c b/F0-nolib/3steppersLB/strfunct.c
index aa22dc4..5476950 100644
--- a/F0-nolib/3steppersLB/strfunct.c
+++ b/F0-nolib/3steppersLB/strfunct.c
@@ -356,6 +356,7 @@ void canid(char *txt){
                 int32_t N;
                 if(eq != getnum(eq, &N) && N > -1 && N < 0xfff){
                     the_conf.CANID = (uint16_t)N;
+                    CAN_reinit(the_conf.CANspeed);
                     good = TRUE;
                 }
             }
@@ -396,27 +397,38 @@ void getcounter(_U_ char *txt){
 void wdcheck(_U_ char *txt){
     while(1){nop();}
 }
-/*
-void stp_check(char *txt){
-    uint8_t N = *txt - '0';
-    if(N < 3){
-        MOTOR_EN(N);
-        MOTOR_CW(N);
-        mottimers[N]->ARR = 300;
-        mottimers[N]->CR1 |= TIM_CR1_CEN;
-    }else{
-        for(N = 0; N < 3; ++N){
-            MOTOR_DIS(N);
-            MOTOR_CCW(N);
-            mottimers[N]->CR1 &= ~TIM_CR1_CEN;
-        }
-    }
-}*/
 
+typedef struct{
+    errcodes code;
+    const char *descr;
+} codetext;
+static const codetext errtxt[] = {
+    {ERR_OK,  "all OK"},
+    {ERR_BADPAR, "wrong parameter's value"},
+    {ERR_BADVAL, "wrong setter of parameter"},
+    {ERR_WRONGLEN, "bad message length"},
+    {ERR_BADCMD, "unknown command"},
+    {ERR_CANTRUN, "temporary can't run given command"},
+    {-1, NULL}
+};
+
+void dumperrcodes(_U_ char *txt){
+    const codetext *c = errtxt;
+    SEND("Error codes:\n");
+    while(c->descr){
+        printu(c->code);
+        SEND(" - ");
+        SEND(c->descr);
+        newline();
+        ++c;
+    }
+    sendbuf();
+}
 
 typedef void(*specfpointer)(char *arg);
 
 enum{
+    SCMD_NONE,  // omit zero
     SCMD_IGNORE,
     SCMD_DELIGNLIST,
     SCMD_DFU,
@@ -431,16 +443,39 @@ enum{
     SCMD_DUMPCONF,
     SCMD_GETCTR,
     SCMD_WD,
+    SCMD_DUMPERR,
+    SCMD_DUMPCMD,
     //SCMD_ST,
     SCMD_AMOUNT
 };
 
+void dumpcmdcodes(_U_ char *txt);
+
+static specfpointer speccmdlist[SCMD_AMOUNT] = {
+    [SCMD_IGNORE] = addIGN,
+    [SCMD_DELIGNLIST] =  delignlist,
+    [SCMD_DFU] =  bootldr,
+    [SCMD_FILTER] =  add_filter,
+    [SCMD_CANSPEED] =  CANini,
+    [SCMD_CANID] =  canid,
+    [SCMD_LISTFILTERS] =  list_filters,
+    [SCMD_IGNBUF] =  print_ign_buf,
+    [SCMD_PAUSE] =  inpause,
+    [SCMD_RESUME] =  inresume,
+    [SCMD_SEND] =  sendCANcommand,
+    [SCMD_DUMPCONF] =  dump_userconf,
+    [SCMD_GETCTR] =  getcounter,
+    [SCMD_WD] = wdcheck,
+    [SCMD_DUMPCMD] = dumpcmdcodes,
+    [SCMD_DUMPERR] = dumperrcodes,
+    //[SCMD_ST] = stp_check,
+};
+
 typedef struct{
     int cmd_code;           // CMD_... or <0 for usb-only commands
     const char *command;    // text command (up to 65536 commands)
     const char *help;       // help message for text protocol
 } commands;
-
 // the main commands list, index is CAN command code
 static const commands textcommands[] = {
     // different commands
@@ -489,6 +524,8 @@ static const commands textcommands[] = {
     {-SCMD_CANSPEED, "canspeed", "CAN bus speed"},
     {-SCMD_DELIGNLIST, "delignlist", "delete ignore list"},
     {-SCMD_DFU, "dfu", "activate DFU mode"},
+    {-SCMD_DUMPERR, "dumperr", "dump error codes"},
+    {-SCMD_DUMPCMD, "dumpcmd", "dump command codes"},
     {-SCMD_DUMPCONF, "dumpconf", "dump current configuration"},
     {-SCMD_FILTER, "filter", "add/modify filter, format: bank# FIFO# mode(M/I) num0 [num1 [num2 [num3]]]"},
     {-SCMD_GETCTR, "getctr", "get TIM1/2/3 counters"},
@@ -503,24 +540,39 @@ static const commands textcommands[] = {
     {0, NULL, NULL}
 };
 
+void dumpcmdcodes(_U_ char *txt){
+    SEND("Commands list:\n");
+    for(uint16_t i = 0; i < CMD_AMOUNT; ++i){
+        printu(i);
+        SEND(" - ");
+        const commands *c = textcommands;
+        while(c->command){
+            if(c->cmd_code == i && *c->command){
+                SEND(c->help); break;
+            }
+            ++c;
+        }
+        newline();
+    }
+    sendbuf();
+}
 
-static specfpointer speccmdlist[SCMD_AMOUNT] = {
-    [SCMD_IGNORE] = addIGN,
-    [SCMD_DELIGNLIST] =  delignlist,
-    [SCMD_DFU] =  bootldr,
-    [SCMD_FILTER] =  add_filter,
-    [SCMD_CANSPEED] =  CANini,
-    [SCMD_CANID] =  canid,
-    [SCMD_LISTFILTERS] =  list_filters,
-    [SCMD_IGNBUF] =  print_ign_buf,
-    [SCMD_PAUSE] =  inpause,
-    [SCMD_RESUME] =  inresume,
-    [SCMD_SEND] =  sendCANcommand,
-    [SCMD_DUMPCONF] =  dump_userconf,
-    [SCMD_GETCTR] =  getcounter,
-    [SCMD_WD] = wdcheck,
-    //[SCMD_ST] = stp_check,
-};
+/*
+void stp_check(char *txt){
+    uint8_t N = *txt - '0';
+    if(N < 3){
+        MOTOR_EN(N);
+        MOTOR_CW(N);
+        mottimers[N]->ARR = 300;
+        mottimers[N]->CR1 |= TIM_CR1_CEN;
+    }else{
+        for(N = 0; N < 3; ++N){
+            MOTOR_DIS(N);
+            MOTOR_CCW(N);
+            mottimers[N]->CR1 &= ~TIM_CR1_CEN;
+        }
+    }
+}*/
 
 static void showHelp(){
     SEND("https://github.com/eddyem/stm32samples/tree/master/F0-nolib/3steppersLB build#" BUILD_NUMBER " @ " BUILD_DATE "\n");
diff --git a/F0-nolib/3steppersLB/version.inc b/F0-nolib/3steppersLB/version.inc
index 3a5ed44..eb844db 100644
--- a/F0-nolib/3steppersLB/version.inc
+++ b/F0-nolib/3steppersLB/version.inc
@@ -1,2 +1,2 @@
-#define BUILD_NUMBER "129"
-#define BUILD_DATE "2021-12-01"
+#define BUILD_NUMBER "139"
+#define BUILD_DATE "2021-12-02"