diff --git a/F3:F303/CANbus4BTA/BTA_CAN.bin b/F3:F303/CANbus4BTA/BTA_CAN.bin
index 53faf23..ca20479 100755
Binary files a/F3:F303/CANbus4BTA/BTA_CAN.bin and b/F3:F303/CANbus4BTA/BTA_CAN.bin differ
diff --git a/F3:F303/CANbus4BTA/Readme.md b/F3:F303/CANbus4BTA/Readme.md
index 9c3c277..a33949a 100644
--- a/F3:F303/CANbus4BTA/Readme.md
+++ b/F3:F303/CANbus4BTA/Readme.md
@@ -122,6 +122,59 @@ Channel1 - ADC1.
 
 ## DMA2
 
+# Other resources usage
+## Timers
+
+- SysTick is 1ms system time counter (`Tms`).
+- TIM2 is 32bit timer with 2mks period (system timestamp for PEP emulation).
+
+## CAN
+
+CAN bus is primary interface.
+
+## USB
+
+USB (PL2303 emulation with iINTERFACE="canbusbta") used as alternate managing interface and for debugging.
+
+## USART
+
+USART1 can be used to operate with external encoder or other device over RS-422.
+
+## SPI
+
+- SPI1 used to work with external SSI encoder.
+- SPI2 used with some external things.
+
+## I2C
+
+not implemented yet
+
+## ADC
+
+ADC1 used to measure internal temperature (CH16) and external:
+
+- CH1 - external power supply (raw value approx Uext/10).
+- CH2 - onboard 5V supply after DC-DC (raw value approx V/2).
+- CH3, CH4 - external inputs through dividers on RV1/R14 and RV2/R15.
+
+## GPIO
+
+GPIOA:
+
+- PA4 - DIN - input of multiplexers U1 and U2.
+- PA5 - DEN0 - enable multiplexer U1.
+- PA6 - DEN1 - enable multiplexer U2.
+
+GPIOB:
+
+- PB0..PB2 - 3bit input address on multiplexer.
+
+GPIOC:
+
+- PC13 - buzzer (not implemented yet).
+- PC14 - relay.
+- PC15 - USB pullup.
+
 # Text command protocol
 Text commands have format of `parameter[number][=setter]`. Where
 - *parameter* is any possible command,
diff --git a/F3:F303/CANbus4BTA/commonfunctions.c b/F3:F303/CANbus4BTA/commonfunctions.c
index ca19889..2e912f3 100644
--- a/F3:F303/CANbus4BTA/commonfunctions.c
+++ b/F3:F303/CANbus4BTA/commonfunctions.c
@@ -43,6 +43,14 @@ static errcodes time_getset(CAN_message *msg){
     *(uint32_t*)&msg->data[4] = Tms;
     return ERR_OK;
 }
+// get/set timestamp
+static errcodes timestamp_getset(CAN_message *msg){
+    if(ISSETTER(msg->data)){
+        TIM2->CNT = *(uint32_t*)&msg->data[4];
+    }else FIXDL(msg);
+    *(uint32_t*)&msg->data[4] = TIM2->CNT;
+    return ERR_OK;
+}
 // get MCU T
 static errcodes mcut(CAN_message *msg){
     FIXDL(msg);
@@ -138,6 +146,11 @@ static errcodes encget(CAN_message *msg){
     if(read_encoder(msg->data + 4)) return ERR_OK;
     return ERR_CANTRUN;
 }
+// reinit encoder
+static errcodes encreinit(CAN_message _U_ *msg){
+    encoder_setup();
+    return ERR_OK;
+}
 
 // common uint32_t setter/getter
 static errcodes u32setget(CAN_message *msg){
@@ -204,6 +217,9 @@ static const commonfunction funclist[CMD_AMOUNT] = {
     [CMD_SPIINIT] = {initspi2, 0, 0, 0},
     [CMD_SPISEND] = {sendspi2, 0, 0, 5},
     [CMD_ENCGET] = {encget, 0, 0, 0},
+    [CMD_EMULPEP] = {flagsetget, 0, 0, 0},
+    [CMD_ENCREINIT] = {encreinit, 0, 0, 0},
+    [CMD_TIMESTAMP] = {timestamp_getset, 0, 0xffffff, 0},
 };
 
 
diff --git a/F3:F303/CANbus4BTA/encoder.c b/F3:F303/CANbus4BTA/encoder.c
index 3969cc7..9e16465 100644
--- a/F3:F303/CANbus4BTA/encoder.c
+++ b/F3:F303/CANbus4BTA/encoder.c
@@ -16,15 +16,23 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "can.h"
 #include "encoder.h"
 #include "flash.h"
+#include "gpio.h"
 #include "spi.h"
 #include "usart.h"
 
+#include <string.h>
 
 void encoder_setup(){
-    if(FLAG(ENC_IS_SSI)) spi_setup(ENCODER_SPI);
-    else usart_setup();
+    if(FLAG(ENC_IS_SSI)){
+        usart_deinit();
+        spi_setup(ENCODER_SPI);
+    }else{
+        spi_deinit(ENCODER_SPI);
+        usart_setup();
+    }
 }
 
 // read encoder value into buffer `outbuf`
@@ -34,3 +42,22 @@ int read_encoder(uint8_t outbuf[4]){
     *((uint32_t*)outbuf) = 0;
     return spi_writeread(ENCODER_SPI, outbuf, 4);
 }
+
+// send encoder data
+void CANsendEnc(){
+    CAN_message msg = {.data = {0}, .ID = the_conf.encoderID, .length = 8};
+    if(!read_encoder(msg.data)) return;
+    uint32_t ctr = TIM2->CNT;
+    //msg.data[4] = 0;
+    msg.data[5] = (ctr >> 16) & 0xff;
+    msg.data[6] = (ctr >> 8 ) & 0xff;
+    msg.data[7] = (ctr >> 0 ) & 0xff;
+    CAN_send(&msg);
+}
+// send limit-switches data
+void CANsendLim(){
+    CAN_message msg = {.data = {0}, .ID = the_conf.limitsID, .length = 8};
+    msg.data[2] = getESW(0);
+    msg.data[3] = getESW(1);
+    CAN_send(&msg);
+}
diff --git a/F3:F303/CANbus4BTA/encoder.h b/F3:F303/CANbus4BTA/encoder.h
index e935349..41addc3 100644
--- a/F3:F303/CANbus4BTA/encoder.h
+++ b/F3:F303/CANbus4BTA/encoder.h
@@ -22,3 +22,5 @@
 
 void encoder_setup();
 int read_encoder(uint8_t outbuf[4]);
+void CANsendEnc();
+void CANsendLim();
diff --git a/F3:F303/CANbus4BTA/flash.c b/F3:F303/CANbus4BTA/flash.c
index 0fbe9ed..f4610d1 100644
--- a/F3:F303/CANbus4BTA/flash.c
+++ b/F3:F303/CANbus4BTA/flash.c
@@ -46,7 +46,9 @@ user_conf the_conf = {
     .adcmul[2] = 1.f,
     .adcmul[3] = 1.f,
     .usartspeed = 115200,
-    .flags = FLAGP(ENC_IS_SSI),
+    .encoderID = 8,
+    .limitsID = 0xe,
+    .flags = FLAGP(ENC_IS_SSI) /*| FLAGP(EMULATE_PEP)*/,
 };
 
 int currentconfidx = -1; // index of current configuration
diff --git a/F3:F303/CANbus4BTA/flash.h b/F3:F303/CANbus4BTA/flash.h
index fe0e8a4..44a958b 100644
--- a/F3:F303/CANbus4BTA/flash.h
+++ b/F3:F303/CANbus4BTA/flash.h
@@ -31,6 +31,8 @@
 // bit flags positions
 // encoder have SSI (1) or RS-422 (0)
 #define ENC_IS_SSI_BIT      0
+// old PEP behaviour
+#define EMULATE_PEP_BIT     1
 
 // bit number
 #define FLAGBIT(f)      (f ## _BIT)
@@ -53,6 +55,8 @@ typedef struct __attribute__((packed, aligned(4))){
     uint32_t bounce_ms;             // debounce wait
     float adcmul[ADC_TSENS];        // ADC voltage multipliers
     uint32_t usartspeed;            // USART1 speed (baud/s)
+    uint16_t encoderID;             // CANbus encoders' ID (PEP emulation)
+    uint16_t limitsID;              // CANbus limits' ID (PEP emulation)
     uint32_t flags;                 // bit flags
 } user_conf;
 
diff --git a/F3:F303/CANbus4BTA/hardware.c b/F3:F303/CANbus4BTA/hardware.c
index 5989c59..b4cd3fe 100644
--- a/F3:F303/CANbus4BTA/hardware.c
+++ b/F3:F303/CANbus4BTA/hardware.c
@@ -46,7 +46,17 @@ TRUE_INLINE void iwdg_setup(){
 }
 #endif
 
-static inline void gpio_setup(){
+// setup TIM2 as 24-bit 2mks timestamp counter
+TRUE_INLINE void tim2_setup(){
+    TIM2->CR1 = 0; // turn off timer
+    RCC->APB1ENR |= RCC_APB1ENR_TIM2EN; // enable clocking
+    TIM2->PSC = 143; // 500kHz
+    TIM2->ARR = 0xffffff; // 24 bit counter from 0xffffff to 0
+    // turn it on, downcounting
+    TIM2->CR1 = TIM_CR1_CEN | TIM_CR1_DIR;
+}
+
+TRUE_INLINE void gpio_setup(){
     RELAY_OFF(); MUL_OFF(0); MUL_OFF(1);
     RCC->AHBENR |= RCC_AHBENR_GPIOAEN | RCC_AHBENR_GPIOBEN | RCC_AHBENR_GPIOCEN;
     // PWM - AF1 @PA7; USB - alternate function 14 @ pins PA11/PA12; SWD - AF0 @PA13/14
@@ -73,6 +83,7 @@ static inline void gpio_setup(){
 }
 
 void hw_setup(){
+    tim2_setup();
     gpio_setup();
     adc_setup();
     USB_setup();
diff --git a/F3:F303/CANbus4BTA/hardware.h b/F3:F303/CANbus4BTA/hardware.h
index 9da78f9..26dd084 100644
--- a/F3:F303/CANbus4BTA/hardware.h
+++ b/F3:F303/CANbus4BTA/hardware.h
@@ -20,6 +20,9 @@
 
 #include <stm32f3.h>
 
+// PEP emulation - period of encoder/esw data send - 70ms
+#define ENCODER_PERIOD  (69)
+
 // USB pullup
 #define USBPU_port  GPIOC
 #define USBPU_pin   (1<<15)
diff --git a/F3:F303/CANbus4BTA/main.c b/F3:F303/CANbus4BTA/main.c
index 56dd9bf..4778379 100644
--- a/F3:F303/CANbus4BTA/main.c
+++ b/F3:F303/CANbus4BTA/main.c
@@ -50,6 +50,7 @@ TRUE_INLINE void showCANmessages(){
 
 int main(void){
     char inbuff[MAXSTRLEN+1];
+    uint32_t encT = 0; // time of ENC and LIM data sent (PEP emulation)
     USBPU_OFF();
     if(StartHSE()){
         SysTick_Config((uint32_t)72000); // 1ms
@@ -75,15 +76,6 @@ int main(void){
             CAN_reinit(0);
         }
         if(cansniffer) showCANmessages();
-        /*if(bufovr){
-            bufovr = 0;
-            USB_sendstr("error=uartoverflow\n");
-        }*/
-        char *txt = NULL;
-        if(usart_getline(&txt)){
-            const char *ans = run_text_cmd(txt);
-            if(ans) usart_send(ans);
-        }
         int l = USB_receivestr(inbuff, MAXSTRLEN);
         if(l < 0) USB_sendstr("error=usboverflow\n");
         else if(l){
@@ -92,13 +84,22 @@ int main(void){
         }
         ESW_process();
         static uint8_t oldswitches[2] = {0};
+        int send = 0;
         for(int i = 0; i < 2; ++i){
             uint8_t new = getESW(i);
             if(oldswitches[i] != new){
+                send = 1;
                 oldswitches[i] = new;
-                USB_sendstr("ESW changed @"); printu(Tms);
+                USB_sendstr("ESW"); USB_putbyte('0' + i);
+                USB_sendstr(" changed @"); printu(Tms);
                 USB_sendstr(" to "); printuhex(new); newline();
             }
         }
+        if(FLAG(EMULATE_PEP)){
+            if(Tms - encT > ENCODER_PERIOD){
+                encT = Tms;
+                CANsendEnc();
+            } else if(send) CANsendLim();
+        }
     }
 }
diff --git a/F3:F303/CANbus4BTA/proto.h b/F3:F303/CANbus4BTA/proto.h
index 186e3f7..9f48e09 100644
--- a/F3:F303/CANbus4BTA/proto.h
+++ b/F3:F303/CANbus4BTA/proto.h
@@ -69,6 +69,9 @@ typedef enum{
     CMD_SPIINIT,    // 16 - init SPI2
     CMD_SPISEND,    // 17 - send 1..4 bytes over SPI
     CMD_ENCGET,     // 18 - get encoder value
+    CMD_EMULPEP,    // 19 - emulate (1) / not (0) PEP
+    CMD_ENCREINIT,  // 20 - reinit encoder
+    CMD_TIMESTAMP,  // 21 - 2mks 24-bit timestamp
     CMD_AMOUNT      // amount of CAN commands
 } can_cmd;
 
diff --git a/F3:F303/CANbus4BTA/spi.c b/F3:F303/CANbus4BTA/spi.c
index 2026617..7867e5c 100644
--- a/F3:F303/CANbus4BTA/spi.c
+++ b/F3:F303/CANbus4BTA/spi.c
@@ -26,6 +26,9 @@
 
 //#define SPIDR   *((volatile uint8_t*)&SPI2->DR)
 
+#define CHKIDX(idx) do{if(idx == 0 || idx > AMOUNT_OF_SPI) return;}while(0)
+#define CHKIDXR(idx) do{if(idx == 0 || idx > AMOUNT_OF_SPI) return 0;}while(0)
+
 spiStatus spi_status[AMOUNT_OF_SPI+1] = {0, SPI_NOTREADY, SPI_NOTREADY};
 static volatile SPI_TypeDef* const SPIs[AMOUNT_OF_SPI+1] = {NULL, SPI1, SPI2};
 #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)
@@ -38,7 +41,7 @@ static volatile SPI_TypeDef* const SPIs[AMOUNT_OF_SPI+1] = {NULL, SPI1, SPI2};
 // Channel 4 - SPI2 Rx
 // Channel 5 - SPI2 Tx
 void spi_setup(uint8_t idx){
-    if(idx > AMOUNT_OF_SPI) return;
+    CHKIDX(idx);
     volatile SPI_TypeDef *SPI = SPIs[idx];
     SPI->CR1 = 0; // clear EN
     SPI->CR2 = 0;
@@ -59,9 +62,9 @@ void spi_setup(uint8_t idx){
         RCC->APB1RSTR = RCC_APB1RSTR_SPI2RST; // reset SPI
         RCC->APB1RSTR = 0; // clear reset
         RCC->APB1ENR |= RCC_APB1ENR_SPI2EN;
-        RCC->AHBENR |= RCC_AHBENR_DMA1EN;
         SPI->CR2 = SPI_CR2_SSOE; // hardware NSS management
         // setup SPI2 DMA
+        //RCC->AHBENR |= RCC_AHBENR_DMA1EN;
         //SPI->CR2 |= SPI_CR2_TXDMAEN | SPI_CR2_RXDMAEN;
         // Tx
         /*DMA1_Channel5->CPAR = (uint32_t)&(SPI2->DR); // hardware
@@ -82,8 +85,25 @@ void spi_setup(uint8_t idx){
     DBG("SPI works");
 }
 
+// turn off given SPI channel and release GPIO
+void spi_deinit(uint8_t idx){
+    CHKIDX(idx);
+    volatile SPI_TypeDef *SPI = SPIs[idx];
+    SPI->CR1 = 0;
+    SPI->CR2 = 0;
+    if(idx == 1){
+        RCC->APB2ENR &= ~RCC_APB2ENR_SPI1EN;
+        GPIOB->AFR[0] = GPIOB->AFR[0] & ~(GPIO_AFRL_AFRL3 | GPIO_AFRL_AFRL4);
+        GPIOB->MODER = GPIOB->MODER & ~(GPIO_MODER_MODER3 | GPIO_MODER_MODER4);
+    }else if(idx == 2){
+        RCC->APB1ENR &= ~RCC_APB1ENR_SPI2EN;
+        GPIOB->AFR[1] = GPIOB->AFR[1] & ~(GPIO_AFRH_AFRH4 | GPIO_AFRH_AFRH5 | GPIO_AFRH_AFRH6 | GPIO_AFRH_AFRH7);
+        GPIOB->MODER = GPIOB->MODER & ~(GPIO_MODER_MODER12 | GPIO_MODER_MODER13 | GPIO_MODER_MODER14 | GPIO_MODER_MODER15);
+    }
+}
+
 int spi_waitbsy(uint8_t idx){
-    if(idx > AMOUNT_OF_SPI) return 0;
+    CHKIDXR(idx);
     WAITX(SPIs[idx]->SR & SPI_SR_BSY);
     return 1;
 }
@@ -95,7 +115,7 @@ int spi_waitbsy(uint8_t idx){
  * @return 0 if failed
  */
 int spi_writeread(uint8_t idx, uint8_t *data, uint32_t n){
-    if(idx > AMOUNT_OF_SPI) return 0;
+    CHKIDXR(idx);
     if(spi_status[idx] != SPI_READY || !data || !n){
         DBG("not ready");
         return 0;
@@ -146,7 +166,7 @@ int spi_writeread(uint8_t idx, uint8_t *data, uint32_t n){
  */
 /*
 int spi_read(uint8_t idx, uint8_t *data, uint32_t n){
-    if(idx > AMOUNT_OF_SPI) return 0;
+    CHKIDXR(idx);
     if(spi_status[idx] != SPI_READY){
         DBG("not ready");
         return 0;
diff --git a/F3:F303/CANbus4BTA/spi.h b/F3:F303/CANbus4BTA/spi.h
index e617fa6..9f3a870 100644
--- a/F3:F303/CANbus4BTA/spi.h
+++ b/F3:F303/CANbus4BTA/spi.h
@@ -29,6 +29,7 @@ typedef enum{
 
 extern spiStatus spi_status[AMOUNT_OF_SPI+1];
 
+void spi_deinit(uint8_t idx);
 void spi_setup(uint8_t idx);
 int spi_waitbsy(uint8_t idx);
 int spi_writeread(uint8_t idx, uint8_t *data, uint32_t n);
diff --git a/F3:F303/CANbus4BTA/textfunctions.c b/F3:F303/CANbus4BTA/textfunctions.c
index bf6638c..fc12ca5 100644
--- a/F3:F303/CANbus4BTA/textfunctions.c
+++ b/F3:F303/CANbus4BTA/textfunctions.c
@@ -58,16 +58,23 @@ static const funcdescr funclist[] = {
     {"cansnif", -TCMD_CANSNIF, "get/change sniffer state (0 - normal, 1 - sniffer)"},
     {"canspeed", CMD_CANSPEED, "get/set CAN speed (bps)"},
     {"dumpconf", -TCMD_DUMPCONF, "dump current configuration"},
+    {"encget", CMD_ENCGET, "read encoder data"},
+    {"encreinit", CMD_ENCREINIT, "reinit encoder"},
+    {"encssi", CMD_ENCISSSI, "encoder is SSI (1) or RS-422 (0)"},
     {"esw", CMD_GETESW, "anti-bounce read ESW of channel 0 or 1"},
     {"eswblk", CMD_GETESW_BLK, "blocking read ESW of channel 0 or 1"},
     {"eraseflash", CMD_ERASESTOR, "erase all flash storage"},
     {"mcutemp", CMD_MCUTEMP, "get MCU temperature (*10degrC)"},
+    {"pepemul", CMD_EMULPEP, "emulate (1) / not (0) PEP"},
     {"relay", CMD_RELAY, "get/set relay state (0 - off, 1 - on)"},
     {"reset", CMD_RESET, "reset MCU"},
     {"s", -TCMD_CANSEND, "send CAN message: ID 0..8 data bytes"},
     {"saveconf", CMD_SAVECONF, "save configuration"},
     {"spiinit", CMD_SPIINIT, "init SPI2"},
-    {"time", CMD_TIME, "get/set time (ms)"},
+    {"spisend", CMD_SPISEND, "send 4 bytes over SPI2"},
+    {"time", CMD_TIME, "get/set time (1ms, 32bit)"},
+    {"timestamp", CMD_TIMESTAMP, "get/set timestamp (2mks, 24bit)"},
+    {"usartspeed", CMD_USARTSPEED, "get/set USART1 speed"},
     {"wdtest", -TCMD_WDTEST, "test watchdog"},
     {NULL, 0, NULL} // last record
 };
diff --git a/F3:F303/CANbus4BTA/usart.c b/F3:F303/CANbus4BTA/usart.c
index 40b84d0..ab3ed58 100644
--- a/F3:F303/CANbus4BTA/usart.c
+++ b/F3:F303/CANbus4BTA/usart.c
@@ -24,7 +24,7 @@
 
 static volatile int idatalen = 0; // received data line length (including '\n')
 
-volatile int linerdy = 0,   // received data ready
+static volatile int linerdy = 0,   // received data ready
     dlen    = 0,            // length of data (including '\n') in current buffer
     bufovr  = 0;            // input buffer overfull
 
@@ -65,9 +65,17 @@ void usart_send(const char *str){
     usart_sendn(str, L);
 }
 
+// turn off USART1 and deinit GPIO
+void usart_deinit(){
+    USART1->ICR = 0xffffffff;
+    USART1->CR1 = 0;
+    RCC->APB2ENR &= ~RCC_APB2ENR_USART1EN;
+    GPIOA->AFR[1] = GPIOA->AFR[1] & ~(GPIO_AFRH_AFRH1 | GPIO_AFRH_AFRH2);
+    GPIOA->MODER = GPIOA->MODER & ~(GPIO_MODER_MODER9 | GPIO_MODER_MODER10);
+}
+
 // USART1: PA10(Rx, pullup), PA9(Tx); USART1 = AF7 @PA9/10;
 void usart_setup(){
-    // clock
     GPIOA->MODER = (GPIOA->MODER & ~(GPIO_MODER_MODER9 | GPIO_MODER_MODER10)) |
                    MODER_AF(9)  | MODER_AF(10);
     GPIOA->AFR[1] = (GPIOA->AFR[1] & ~(GPIO_AFRH_AFRH1 | GPIO_AFRH_AFRH2)) |
diff --git a/F3:F303/CANbus4BTA/usart.h b/F3:F303/CANbus4BTA/usart.h
index a0198e0..e75f1ce 100644
--- a/F3:F303/CANbus4BTA/usart.h
+++ b/F3:F303/CANbus4BTA/usart.h
@@ -23,9 +23,8 @@
 // input buffers size
 #define UARTBUFSZ  (80)
 
-extern volatile int linerdy, bufovr;
-
 void usart_setup();
+void usart_deinit();
 int usart_getline(char **line);
 void usart_send(const char *str);
 void usart_sendn(const char *str, int L);
diff --git a/F3:F303/CANbus4BTA/version.inc b/F3:F303/CANbus4BTA/version.inc
index cb5140d..afd5a14 100644
--- a/F3:F303/CANbus4BTA/version.inc
+++ b/F3:F303/CANbus4BTA/version.inc
@@ -1,2 +1,2 @@
-#define BUILD_NUMBER "80"
-#define BUILD_DATE "2024-03-07"
+#define BUILD_NUMBER "84"
+#define BUILD_DATE "2024-03-08"