;********************************************************************** ; T628A16.ASM ;********************************************************************** ; ; Progetto: ; TERMOIGROMETRO RS485 ; ; Autore: ; Sergio Tanzilli (http://www.tanzilli.com) ; ; Versione: ; 26/03/2004 Revisione per PIC16F628A ; 1/02/2004 Porting su PICmicro 16F628 su scheda ST01 versione 1.00 ; 18/06/2003 Versione per SHT71 ; 3/05/2004 Versione per scheda ST01 versione 2.0 ; ; Modifiche da fare: ; ; Il campo SNAP NDB per ora non e' compatibile con le specifiche SNAP in ; quanto il suo valore viene usato cosi' com'e' e non come indice ; per la tabella delle lunghezze definite dal protocollo. ; ; Note sulla compatibilità con SNAP ; ; Molte caratteristiche previste dal protocollo SNAP non vengono ; implementate (www.hth.com). I pacchetti hanno un campo di indirizzamento ; fisso a 8 bit e l'unico controllo d'errore e' il CRC16 ; ;********************************************************************** PROCESSOR 16F628A RADIX DEC INCLUDE "P16F628A.INC" ERRORLEVEL -302 ;Elimina la segnalazione di warning n.302 __CONFIG 0x3F62 #define MY_ADDR 20 ;Indirizzo di questo nodo #define MASTER_ADDR 0 ;Indirizzo del dispositivo master #define MAXPOLLINGDELAY 150 ;Ritardo massimo di polling (s) prima di accendere ;il led rosso #define DATA_BIT PORTA,0 ;Port A0 linea dati del sensore #define CLOCK_BIT PORTA,1 ;Port A1 linea del clock del sensore #define COM_DE PORTB,3 ;Port B3 linea di abilitazione tx RS485 (1=abilitato) #define LED_ROSSO PORTB,4 ;Port B4 Led Rosso #define LED_VERDE PORTB,5 ;Port B5 Led Verde #define L_VERDE PORTA,4 ;Port A5 Led Verde #define INGRESSO PORTB,0 ;Comandi riconosciuti dal sensore SHT71 #define CMD_READ_TEMP 0x03 ;Comando di lettura temperatura #define CMD_READ_HUM 0x05 ;Comando di lettura umidità ;********************************************************************** ; Parametri SNAP ;********************************************************************** ;Frame coding #define SNAP_ACK 0x10 #define SNAP_NACK 0x02 #define SNAP_SYNC 0x54 ;SNAP Frame properties #define TX_MAX_DL 16 ;Max data lenght on tx packet #define RX_MAX_DL 16 ;Max data lenght on rx packet ;RX buffer status flags (tzn_rxb_flag) #define RX_DATA_READY 1 ;Data buffer contains valid data #define RX_FLOW_ON 2 ;Byte are coming from rx line ;RX packet status flags (tzn_rxp_flag) ;Please refer to SNAP protocol definitions on http://www.hth.com #define RX_SYNC 0 ;SYNC byte received #define RX_HDB2 1 ;HDB2 byte received #define RX_HDB1 2 ;HDB1 byte received #define RX_DAB1 3 ;DAB1 byte received #define RX_SAB1 4 ;SAB1 byte received #define RX_DB 5 ;DB byte received #define RX_CRC2 6 ;CRC2 byte received ;TX status register flags (tzn_txb_flag) #define TX_DATA_READY 1 ;Tx buffer with data to transmit #define RX_TIMEOUT 10 ;Timeout in ricezione. Indica il tempo massimo che il PIC aspetta ;tra un carattere e l'altro superato il quale annulla la ricezione ;dell'intero pacchetto. 2 = 1ms ;File register on BANK 0 #define W_TEMP 0x20 ;Temporany register used to save and restore W, STATUS, #define STATUS_TEMP 0x21 ;PCLATH and FSR register while an interrupt handler #define PCLATH_TEMP 0x22 ;routine is executed #define FSR_TEMP 0x23 #define msDelayTimer 0x24 ;msDelay subroutine counter #define msDelayTmp 0x25 org 0xA0 ;File register on BANK 1 W_TEMP_mirrow res 1 ;Questo registro viene usato per memorizzare il valore ;dell'accumulatore quando si verifica un interrupt. Non ;cambiarne l'indirizzo !! saveSTATUS res 1 tzn_rxp_flag res 1 ;Rx packet status flags tzn_rxb_flag res 1 ;Rx buffer status flags RxNDB res 1 ;Number of Data Bytes extract from NDB field RxCRC2 res 1 ;CRC16 del pacchetto ricevuto RxCRC1 res 1 RxDataCounter res 1 RxWritePointer res 1 RxToutTimer res 1 rxDummyCounter res 1 RxCRC_Temp res 1 RxCRC_Count res 1 RxCRC_High res 1 RxCRC_Low res 1 RxIncomingChar res 1 txNDB res 1 TxBitDelayCount res 1 ;Contatore utilizzato nella macro ONE_BIT_DELAY txDummyCounter res 1 TxCRC_Temp res 1 TxCRC_Count res 1 TxCRC_High res 1 TxCRC_Low res 1 sysTimer0L res 1 sysTimer0H res 1 inputTimer res 1 TestLedCounter res 2 ;Tx Buffer tzn_txheader res 4 ;Tx header tzn_txdata res TX_MAX_DL ;Tx max data len tzn_txcrc res 2 ;Tx CRC16 ;Rx Buffer tzn_rxdata res RX_MAX_DL last_register res 1 ;Questo registro non viene usato dal programma mi serve solo ;per vedere quanta memoria RAM ho usato ;********************************************************************** ; Registri ;********************************************************************** org 0x30 firstdata res 1 myCounter res 1 ;Variabili usate dalle routine di lettura dal sensore SHT71/75 LoopVar res 1 Temp res 1 DelayL res 1 DelayH res 1 WithAck res 1 TempL res 1 TempH res 1 HumL res 1 HumH res 1 Checksum res 1 Delay_cnt1 res 1 Delay_cnt2 res 1 ReadDelay res 1 UTToggle res 1 pollAllarm res 1 ;********************************************************************** ; Macro usate per SNAP ;********************************************************************** ONE_BIT_DELAY MACRO LOCAL OneBitDelayLoop movlw 72 ;Wait a bit (Clock 16Mhz) movwf TxBitDelayCount OneBitDelayLoop decfsz TxBitDelayCount,F goto OneBitDelayLoop ENDM ; Swap to register bank 0 SWAP_TO_BANK0 MACRO bcf STATUS,RP0 ;Point to BANK 0 ENDM ; Swap to register bank 1 SWAP_TO_BANK1 MACRO bsf STATUS,RP0 ;Point to BANK 1 ENDM ;************************************************************************* ; Inizializza ed abilita la sezione RX ;************************************************************************* INIT_RX MACRO SWAP_TO_BANK1 clrf tzn_rxb_flag ;Clear all rx flags clrf tzn_rxp_flag SWAP_TO_BANK0 bcf RCSTA,CREN bsf RCSTA,CREN movf RCREG,W ;Empty USART RX buffer bcf COM_DE ;Disable RS485 driver SWAP_TO_BANK1 bsf PIE1,RCIE ;Enable the USART receive interrupt ENDM ; Macro per le linee clock e dati DATA_LINE_IN MACRO SWAP_TO_BANK1 ;bsf TRISA, DATA_BIT bsf DATA_BIT SWAP_TO_BANK0 ENDM DATA_LINE_OUT MACRO SWAP_TO_BANK1 ;bcf TRISA, DATA_BIT bcf DATA_BIT SWAP_TO_BANK0 ENDM DATA_LINE_LOW MACRO bcf DATA_BIT ENDM ; Legge la linea dati. Salta se è a 1 DATA_LINE_READ MACRO btfss DATA_BIT ENDM DATA_LINE_HIGH MACRO bsf DATA_BIT ENDM CLOCK_LINE_LOW MACRO bcf CLOCK_BIT ENDM CLOCK_LINE_HIGH MACRO bsf CLOCK_BIT ENDM ;********************************************************************** ; Reset vector ;********************************************************************** ORG 0x00 goto Main ORG 0x04 goto Interrupt_handler ;********************************************************************** ; Invia la sequenza di start al sensore ;********************************************************************** SendStart DATA_LINE_OUT CLOCK_LINE_HIGH nop nop nop DATA_LINE_LOW CLOCK_LINE_LOW nop nop nop CLOCK_LINE_HIGH nop nop nop DATA_LINE_HIGH CLOCK_LINE_LOW DATA_LINE_IN return ;********************************************************************** ; Invia un reset logico al sensore ;********************************************************************** SendReset movlw 0x0B movwf LoopVar ResetLoop CLOCK_LINE_HIGH nop nop nop CLOCK_LINE_LOW decfsz LoopVar, F goto ResetLoop return ;********************************************************************** ; Invia un byte ; il byte deve essere in W ; Torna 1 se tutto OK, 0 altrimenti ;********************************************************************** SHT_SendByte ; Valore del byte in Temp DATA_LINE_OUT movwf Temp ; Inizializzazione del Loop movlw 0x80 movwf LoopVar SendLoop ; Se il bit è 1 alzo la linea dati movf Temp,W andwf LoopVar,W btfsc STATUS,Z goto Set0 DATA_LINE_HIGH goto Prosegui Set0 DATA_LINE_LOW Prosegui CLOCK_LINE_HIGH nop nop nop CLOCK_LINE_LOW ; Controllo il fine loop bcf STATUS,C rrf LoopVar,F movf LoopVar,F btfss STATUS,Z goto SendLoop ; Aspetta l'ACK DATA_LINE_IN CLOCK_LINE_HIGH ; Carico il timeout movlw 0xFF movwf DelayL WaitAck ; Attende che la linea dati torni bassa DATA_LINE_READ goto AckReceived ; Controllo il timeout decfsz DelayL,F goto WaitAck retlw 0x00 AckReceived ; ACK Ricevuto CLOCK_LINE_LOW retlw 0x01 ;********************************************************************** ; Legge un byte ; Se la variabile WithAck è 1 manda l'ack, altrimenti no ; Ritorna con il byte letto in W ;********************************************************************** ReadByte clrf Temp DATA_LINE_IN ; Inizializzazione del Loop movlw 0x80 movwf LoopVar ReceiveLoop CLOCK_LINE_HIGH nop nop nop ; Leggo la linea dati, se 0 proseguo, altrimenti setto il bit DATA_LINE_READ goto ReceiveProsegui movf LoopVar,W iorwf Temp, F ReceiveProsegui CLOCK_LINE_LOW; ; Controllo il fine loop bcf STATUS,C rrf LoopVar,F movf LoopVar,F btfss STATUS,Z goto ReceiveLoop ; Ok, byte terminato. Mando l'ACK se richiesto btfss WithAck,0 goto NoAkcRequested ; Acknowledge del byte DATA_LINE_OUT DATA_LINE_LOW CLOCK_LINE_HIGH nop nop nop CLOCK_LINE_LOW DATA_LINE_IN ; Ritorna il valore letto movf Temp,W return NoAkcRequested ; Senza acknowledge DATA_LINE_OUT DATA_LINE_HIGH CLOCK_LINE_HIGH nop nop nop CLOCK_LINE_LOW DATA_LINE_IN ; Ritorna il valore letto movf Temp,W return ;********************************************************************** ; Legge la temperatura ; Riporta il valore in TempL e TempH ;********************************************************************** ReadTemperature ; Invia la sequenza di startup call SendStart ; Invia il comando di lettura movlw CMD_READ_TEMP call SHT_SendByte ; Controllo se è andato tutto bene, altrimenti resetto ed esco andlw 0x01 btfss STATUS,Z goto ProseguiReadTemp call SendReset retlw 0x00 ProseguiReadTemp ; Attende che la misura sia disponibile (linea dati bassa) DATA_LINE_READ goto EndReadT goto ProseguiReadTemp EndReadT ; Legge i byte di dati clrf WithAck incf WithAck,F call ReadByte movwf TempH call ReadByte movwf TempL clrf WithAck call ReadByte movwf Checksum retlw 0x01 ;********************************************************************** ; Legge l'umidità ; Riporta il valore in HumL e HumH ;********************************************************************** ReadHumidity ; Invia la sequenza di startup call SendStart ; Invia il comando di lettura movlw CMD_READ_HUM call SHT_SendByte ; Controllo se è andato tutto bene, altrimenti resetto ed esco andlw 0x01 btfss STATUS,Z goto ProseguiReadHum call SendReset retlw 0x00 ProseguiReadHum ; Attende che la misura sia disponibile (linea dati bassa) DATA_LINE_READ goto EndReadH goto ProseguiReadHum EndReadH ; Legge i byte di dati clrf WithAck incf WithAck,F call ReadByte ;****************************** ; movlw 0 ; btfss INGRESSO ; movlw 10 ;****************************** movwf HumH call ReadByte ;****************************** ; movlw 0 ; btfss INGRESSO ; movlw 10 ;****************************** movwf HumL clrf WithAck call ReadByte movwf Checksum retlw 0x01 ;********************************************************************** ;********************************************************************** ;********************************************************************** ;********************************************************************** ; Main ;********************************************************************** ;********************************************************************** ;********************************************************************** ;********************************************************************** Main clrf STATUS ; Init BANK1 register SWAP_TO_BANK1 ;Set the default the I/O lines state ;RA0 (pin 17) <-> Data line SH7x ;RA1 (pin 18) --> Clock line SHT7x ;RA2 (pin 1) <-- 0=Termo 1=Opto ;RA3 (pin 2) <-- 0=Aperto 1=Chiuso ;RA4 (pin 3) --> N.C ;RB0 (pin 6) --> Niente ;RB1 (pin 7) <-- RS485 RXD ;RB2 (pin 8) --> RS485 TXD ;RB3 (pin 9) --> RS485 DE ;RB4 (pin 10) --> LED Rosso ;RB5 (pin 11) --> LED Verde ;RB6 (pin 12) --> PGC ;RB7 (pin 13) --> PGD movlw 00000100B ; Modificato RA2, è diventato ingresso. movwf TRISA movlw 00000011B movwf TRISB ;Reset all registers on bank 1 movlw 0xA0 movwf FSR InitBank1Loop clrf INDF incf FSR,F btfss STATUS,Z goto InitBank1Loop INIT_RX SWAP_TO_BANK1 movlw 12 ;19200 baud (Clock = 16Mhz) movwf SPBRG bcf TXSTA,SYNC ;Asynchronous mode bsf TXSTA,TXEN ;Transmit enabled bcf TXSTA,TX9 ;Select 8 bit transmission bcf TXSTA,BRGH ;Low speed bsf PIE1,RCIE ;Enables the USART to generate RX interrupt bcf PIE1,TXIE ;Disables the USART to generate TX interrupt bcf OPTION_REG,NOT_RBPU ;Port B pull up enabled bcf OPTION_REG,T0CS ;Timer0 source internal cycle clock bcf OPTION_REG,PSA ;Prescaler in assigned to the Timer0 ;Set the prescaler (Clock = 16Mhz) bcf OPTION_REG,PS2 ;Prescaler 1:16 bsf OPTION_REG,PS1 ;16MHz/4 = 4MHz/8 = 500KHz/(256-6) = 2KHz bcf OPTION_REG,PS0 ;to obtain a TMR0 interrupt each 0.5ms ;Init BANK0 register SWAP_TO_BANK0 ;Reset all registers on bank 0 movlw 0x20 movwf FSR InitBank0Loop clrf INDF incf FSR,F movlw 0x80 xorwf FSR,W btfss STATUS,Z goto InitBank0Loop movlw 0x07 ;Porta A in modalità digitale (Vedi pagina 53) movwf CMCON ;Init register bsf RCSTA,SPEN ;Serial port enabled bsf RCSTA,CREN ;Enables continuous receive bcf RCSTA,RX9 ;Select 8 bit reception movlw 6 movwf TMR0 bsf INTCON,T0IE ;Enables TMR0 overflow interrupt bsf INTCON,PEIE ;Enables all un-masked peripheral interrupts bsf INTCON,GIE ;Enables Global Interrupt bcf COM_DE ;Disable RS485 tx driver bcf LED_ROSSO bcf LED_VERDE movlw MAXPOLLINGDELAY movwf pollAllarm ;********************************************************************** ; LOOP PRINCIPALE ;********************************************************************** MainLoop SWAP_TO_BANK0 check_rx_buffer SWAP_TO_BANK1 btfss tzn_rxb_flag,RX_DATA_READY ;Ci sono dati validi ? goto _check_rx_buffer ;No, passa al task successivo ;Si, controlla cosa e' stato ricevuto ;--------------------------------------------------------------- ; 0x02 Richiesta di trasmissione dei valori di temperatura ; ed umidita ; ; Risposta nel campo NDB: ; ; [TempH] [TempL] [HumH] [HumL] ;--------------------------------------------------------------- CmdReadData SWAP_TO_BANK1 movlw 0x02 xorwf tzn_rxdata,W btfss STATUS,Z goto _CmdReadData SWAP_TO_BANK0 movf TempH,W SWAP_TO_BANK1 movwf tzn_txdata+0 SWAP_TO_BANK0 movf TempL,W SWAP_TO_BANK1 movwf tzn_txdata+1 SWAP_TO_BANK0 movf HumH,W SWAP_TO_BANK1 movwf tzn_txdata+2 SWAP_TO_BANK0 movf HumL,W SWAP_TO_BANK1 movwf tzn_txdata+3 movlw 4 movwf txNDB ;Attende prima di trasmettere la risposta SWAP_TO_BANK0 movlw 10 call msDelay SWAP_TO_BANK1 SWAP_TO_BANK0 bsf LED_ROSSO call SendPacket SWAP_TO_BANK1 INIT_RX goto _endCheckPacket _CmdReadData _endCheckPacket ;Spegne il led rosso SWAP_TO_BANK0 movlw MAXPOLLINGDELAY movwf pollAllarm bcf LED_ROSSO _check_rx_buffer ;********************************************************************** ; Lettura a ciclo continuo dei dati dal sensore SHTxx ;********************************************************************** ReadFromSHT71 SWAP_TO_BANK0 movf ReadDelay,W btfss STATUS,Z goto _ReadFromSHT71 btfss UTToggle,0 goto ReadTempFromSHT71 goto ReadUmidFromSHT71 ReadTempFromSHT71 bsf UTToggle,0 call ReadTemperature goto _ReadFromSHT71 ReadUmidFromSHT71 bcf UTToggle,0 call ReadHumidity goto _ReadFromSHT71 _ReadFromSHT71 incf ReadDelay,F goto MainLoop ;********************************************************************** ; Interrupt handler ;********************************************************************** Interrupt_handler ;Save the registers MOVWF W_TEMP ;Copy W to TEMP register, could be bank one or zero SWAPF STATUS,W ;Swap STATUS to be saved into W CLRF STATUS ;bank 0, regardless of current bank, Clears IRP,RP1,RP0 MOVWF STATUS_TEMP ;Save status to bank zero STATUS_TEMP register MOVF PCLATH, W ;Only required if using pages 1, 2 and/or 3 MOVWF PCLATH_TEMP ;Save PCLATH into W CLRF PCLATH ;Page zero, regardless of current page BCF STATUS, IRP ;Return to Bank 0 MOVF FSR, W ;Save FSR MOVWF FSR_TEMP clrf STATUS ;Point to BANK 0 ;Check interrupt source and call its own handler btfsc PIR1,RCIF ;Check for USART rx char interrupt goto USART_RCIF_Handler btfsc INTCON,T0IF ;Check for TMR0 overflow interrupt goto TMR0_T0IF_Handler btfsc PIR1,TMR1IF ;Check for TIMER1 interrupt goto TMR1IF_Handler _Interrupt_handler ;Restore the registers and return from the interrupt SWAP_TO_BANK0 MOVF FSR_TEMP, W ;Restore FSR MOVWF FSR MOVF PCLATH_TEMP, W ;Restore PCLATH MOVWF PCLATH SWAPF STATUS_TEMP,W ;Swap STATUS_TEMP register into W ;(sets bank to original state) MOVWF STATUS ;Move W into STATUS register SWAPF W_TEMP,F ;Swap W_TEMP SWAPF W_TEMP,W ;Swap W_TEMP into W retfie ;********************************************************************** ; USART rx char interrupt ;********************************************************************** USART_RCIF_Handler movf RCREG,W ;Save the byte received SWAP_TO_BANK1 movwf RxIncomingChar ;********************************************************************** ; Check for the rx buffer status ;********************************************************************** btfsc tzn_rxb_flag,RX_DATA_READY ;Does the buffer already contains any good data ? goto _USART_RCIF_Handler ;Yes, exit and lost the byte received ;No, continue bsf tzn_rxb_flag,RX_FLOW_ON ;Segnala la presenza di un flusso di dati in ricezione ;(Questo flag viene azzerato su timeout) ;********************************************************************** ; Check for SNAP_SYNC char ;********************************************************************** CheckSYNC btfsc tzn_rxp_flag,RX_SYNC ;Is the SYNC byte already received ? goto _CheckSYNC ;Yes, continue ;No, check if a SYNC character is incoming movlw SNAP_SYNC ;Is the byte received a SYNC ? xorwf RxIncomingChar,W btfss STATUS,Z goto _USART_RCIF_Handler ;No, it should be a preamble char or anything else then trash ;the byte received bsf tzn_rxp_flag,RX_SYNC ;Yes, set RX_SYNC flag and exit clrf RxToutTimer ;Reset Rx timeout goto _USART_RCIF_Handler ;Exit from interrupt handler _CheckSYNC ;********************************************************************** ; Checks for HDB2 char ;********************************************************************** CheckHDB2 btfsc tzn_rxp_flag,RX_HDB2 ;Is the HDB2 byte already received ? goto _CheckHDB2 ;Yes, continue movf RxIncomingChar,W ;Is DAB=01B and SAB=01B and PDB=00 ? andlw 11111100B movwf rxDummyCounter movlw 01010000B xorwf rxDummyCounter,W btfss STATUS,Z goto ResetRxSession ;No, Reset Rx session and exit ;Reset CRC16 fields clrf RxCRC_Low clrf RxCRC_High ;Calculate CRC16 movf RxIncomingChar,W call CalcRxCRC ;!!! Inserire qui il codice per sapere se e' richiesto o meno l'ACK !!! bsf tzn_rxp_flag,RX_HDB2 ;Yes, set RX_HDB2 flag clrf RxToutTimer ;Reset Rx timeout goto _USART_RCIF_Handler ;Exit from interrupt handler _CheckHDB2 ;********************************************************************** ; Checks for HDB1 char ;********************************************************************** CheckHDB1 btfsc tzn_rxp_flag,RX_HDB1 ;Is the HDB1 byte already received ? goto _CheckHDB1 ;Yes, continue movf RxIncomingChar,W ;Is C=0B and EDM=100 ? andlw 11110000B movwf rxDummyCounter movlw 01000000B xorwf rxDummyCounter,W btfss STATUS,Z goto ResetRxSession ;No, reset the rx session and exit movf RxIncomingChar,W ;Read the NDB field (Number of Data Bytes) andlw 00001111B movwf RxNDB ;Calculate CRC16 movf RxIncomingChar,W call CalcRxCRC bsf tzn_rxp_flag,RX_HDB1 ;Yes, set RX_HDB1 flag clrf RxToutTimer ;Reset Rx timeout goto _USART_RCIF_Handler ;Exit from interrupt handler _CheckHDB1 ;********************************************************************** ; Checks for DAB1 char (Destination Address Byte) ;********************************************************************** CheckDAB1 btfsc tzn_rxp_flag,RX_DAB1 ;Is the DAB1 byte already received ? goto _CheckDAB1 ;Yes, continue ;Legge i dip switch esterni se richiesto #ifdef EX_ADDR_ENABLED SWAP_TO_BANK0 swapf PORTB,W andlw 0x0F iorlw MY_ADDR SWAP_TO_BANK1 #else movlw MY_ADDR ;Is DAB1 = My address ? #endif xorwf RxIncomingChar,W btfss STATUS,Z goto ResetRxSession ;No, Reset Rx session and exit ;Calculate CRC16 movf RxIncomingChar,W call CalcRxCRC bsf tzn_rxp_flag,RX_DAB1 ;Yes, set RX_DAB1 flag clrf RxToutTimer ;Reset Rx timeout goto _USART_RCIF_Handler ;Exit from interrupt handler _CheckDAB1 ;********************************************************************** ; Read and save SAB1 (Source Address Byte) ;********************************************************************** CheckSAB1 btfsc tzn_rxp_flag,RX_SAB1 ;Is the SAB1 byte already received ? goto _CheckSAB1 ;Yes, continue ;Inserire qui il codice per leggere il nodo che ha trasmesso il pacchetto ;Calculate CRC16 movf RxIncomingChar,W call CalcRxCRC bsf tzn_rxp_flag,RX_SAB1 ;Yes, set RX_SAB1 flag clrf RxDataCounter ;Clear rx chars counter movlw tzn_rxdata ;Init rx buffer write pointer movwf RxWritePointer clrf RxToutTimer ;Reset Rx timeout goto _USART_RCIF_Handler ;Exit from interrupt handler _CheckSAB1 ;********************************************************************** ; Save the data bytes ;********************************************************************** CheckDB btfsc tzn_rxp_flag,RX_DB ;Are the user data already received ? goto _CheckDB ;Yes, continue incf RxDataCounter,F ;Increments data counter ; Save the data received in the RxBuffer movf RxWritePointer,W ;FSR = rx buffer write pointer movwf FSR ;Calculate CRC16 movf RxIncomingChar,W call CalcRxCRC movf RxIncomingChar,W movwf INDF ;Save rx character in tzn_rxbuffer incf RxWritePointer,F ; Check if is the last data byte movf RxNDB,W ;Is the NDB field (on the packet header) equals to the current rx data counter ? xorwf RxDataCounter,W btfsc STATUS,Z bsf tzn_rxp_flag,RX_DB ;Yes, set RX_DB flag clrf RxToutTimer ;Reset Rx timeout goto _USART_RCIF_Handler ;Exit from interrupt handler _CheckDB ;********************************************************************** ; Checks for CRC2 char ;********************************************************************** CheckCRC2 btfsc tzn_rxp_flag,RX_CRC2 ;Is the CRC2 byte already received ? goto _CheckCRC2 ;Yes, continue movf RxIncomingChar,W movwf RxCRC2 bsf tzn_rxp_flag,RX_CRC2 ;Yes, set RX_CRC2 flag clrf RxToutTimer ;Reset Rx timeout goto _USART_RCIF_Handler ;Exit from interrupt handler _CheckCRC2 ;********************************************************************** ; Checks for CRC1 char ;********************************************************************** CheckCRC1 movf RxIncomingChar,W movwf RxCRC1 ;Compare the CRC16 received with the CRC16 calculated movf RxCRC_High,W xorwf RxCRC2,W btfss STATUS,Z goto ResetRxSession ;No, Reset Rx session and exit movf RxCRC_Low,W xorwf RxCRC1,W btfss STATUS,Z goto ResetRxSession ;No, Reset Rx session and exit ;Packet ready !!! bsf tzn_rxb_flag,RX_DATA_READY ;Received buffer now is ready with valid data goto _USART_RCIF_Handler ;Exit from interrupt handler _CheckCRC1 ResetRxSession INIT_RX _USART_RCIF_Handler goto _Interrupt_handler ;********************************************************************** ; TMR0 overflow interrupt handler ; This routine is calling each 1/2 millisecond and checks and updates ; all the system timer ;********************************************************************** TMR0_T0IF_Handler ;********************************************************************** ; TMR0 TASK1 ; Re-enables TMR0 interrupt and reload TMR0 register ;********************************************************************** tmr0_task_1 SWAP_TO_BANK1 bcf INTCON,T0IF ;Re-enables TMR0 interrupt SWAP_TO_BANK0 movlw 6 ;Reload TMR0 register movwf TMR0 _tmr0_task_1 ;********************************************************************** ; TMR0 TASK2 ; Update system timer ;********************************************************************** tmr0_task_2 SWAP_TO_BANK0 incf msDelayTimer,F UpdateSysTimer SWAP_TO_BANK1 incf sysTimer0L,F btfsc STATUS,Z incf sysTimer0H,F movf sysTimer0L,W xorlw 0xE8 btfss STATUS,Z goto _UpdateSysTimer movf sysTimer0H,W xorlw 0x03 btfss STATUS,Z goto _UpdateSysTimer clrf sysTimer0L clrf sysTimer0H movf inputTimer,W btfss STATUS,Z decf inputTimer,F _UpdateSysTimer _tmr0_task_2 ;********************************************************************** ; TMR0 TASK3 ; Check timeout on rx to close rx data flow ;********************************************************************** tmr0_task_3 btfsc tzn_rxb_flag,RX_DATA_READY ;RX_DATA_READY ? goto _tmr0_task_3 ;Yes, exit btfss tzn_rxb_flag,RX_FLOW_ON ;RX_FLOW_ON ? goto _tmr0_task_3 ;No, exit incf RxToutTimer,F movlw RX_TIMEOUT ;Timeout ? xorwf RxToutTimer,W btfss STATUS,Z goto _tmr0_task_3 ;No, exit INIT_RX ;Yes, reset the rx section for timeout _tmr0_task_3 SWAP_TO_BANK0 ;********************************************************************** ; TMR0 TASK5 ; Flash test led ;********************************************************************** tmr0_task_5 SWAP_TO_BANK1 incf TestLedCounter+0,F movlw 200 ;10 ms ? xorwf TestLedCounter+0,W btfss STATUS,Z goto _tmr0_task_5 ;No, exit clrf TestLedCounter+0 incf TestLedCounter+1,F ;Yes movlw 10 ;1 sec ? xorwf TestLedCounter+1,W btfss STATUS,Z goto _tmr0_task_5 ;No, exit clrf TestLedCounter+1 ;Yes, flash test led SWAP_TO_BANK0 decfsz pollAllarm,F ;Accende il led rosso se il polling goto noPollAllarm bcf LED_ROSSO ;non arriva dopo n secondi noPollAllarm btfsc LED_VERDE ;Toggle del led verde goto _testled_off goto _testled_on _testled_off bcf LED_VERDE goto _tmr0_task_5 _testled_on bsf LED_VERDE goto _tmr0_task_5 _tmr0_task_5 SWAP_TO_BANK0 goto _Interrupt_handler ;Exit from interrupt handler ;********************************************************************** ; TMR1IF interrupt handler ; Non utilizzato ;********************************************************************** TMR1IF_Handler SWAP_TO_BANK0 bcf PIR1,0 ;Reset TIMER1 interrupt flag _TMR1IF_Handler goto _Interrupt_handler ;********************************************************************** ; Delay of W ms (uses TMR0 interrupt) ;********************************************************************** msDelay movwf msDelayTmp clrf msDelayTimer msDelayLoop movf msDelayTimer,W xorwf msDelayTmp,W btfss STATUS,Z goto msDelayLoop return ;********************************************************************** ; CRC16 calculator for interrupt handler routine ; Thanks to Frank Vorstenbosch author of this routine ;********************************************************************** CalcRxCRC SWAP_TO_BANK1 movwf RxCRC_Temp movlw 8 movwf RxCRC_Count RxCRC_Loop movf RxCRC_Low,W xorwf RxCRC_Temp,W clrc rrf RxCRC_High,F rrf RxCRC_Low,F andlw 1 bz RxCRC_Skip movlw 0xA0 xorwf RxCRC_High,F movlw 0x01 xorwf RxCRC_Low,F RxCRC_Skip rrf RxCRC_Temp,F decfsz RxCRC_Count,F goto RxCRC_Loop return ;********************************************************************** ; CRC16 calculator for non interrupt handler routine ; Thanks to Frank Vorstenbosch author of this routine ;********************************************************************** CalcTxCRC SWAP_TO_BANK1 movwf TxCRC_Temp movlw 8 movwf TxCRC_Count TxCRC_Loop movf TxCRC_Low,W xorwf TxCRC_Temp,W clrc rrf TxCRC_High,F rrf TxCRC_Low,F andlw 1 bz TxCRC_Skip movlw 0xA0 xorwf TxCRC_High,F movlw 0x01 xorwf TxCRC_Low,F TxCRC_Skip rrf TxCRC_Temp,F decfsz TxCRC_Count,F goto TxCRC_Loop return ;********************************************************************** ; Send a SNAP packet to the Master node ;---------------------------------------------------------------------- ; Input parameters: ; ; MY_ADDR = My address ; MASTER_ADDR = Target address ; ; txNDB = Number of Data Bit ;********************************************************************** SendPacket SWAP_TO_BANK0 bcf INTCON,GIE ;Disables Global Interrupt bsf COM_DE ;Enable RS485 driver ;Assemble the frame header SWAP_TO_BANK1 movlw 01010000B ;HDB2 movwf tzn_txheader+0 movlw 01000000B ;HDB1 movwf tzn_txheader+1 movf txNDB,W iorwf tzn_txheader+1,F ;Inserisce in HDB1 il campo NDB (Number on Data Bytes) movlw MASTER_ADDR ;DAB1 movwf tzn_txheader+2 #ifdef EX_ADDR_ENABLED SWAP_TO_BANK0 swapf PORTB,W andlw 0x0F iorlw MY_ADDR SWAP_TO_BANK1 #else movlw MY_ADDR #endif movwf tzn_txheader+3 ;************************************************ ; Send frame ;************************************************ ;Send preamble bytes SWAP_TO_BANK1 clrf TxCRC_High clrf TxCRC_Low movlw SNAP_SYNC call SendByte movlw SNAP_SYNC call SendByte ;Send frame header SWAP_TO_BANK1 movlw 4 movwf txDummyCounter movlw tzn_txheader movwf FSR _TxHeaderLoop movf INDF,W call SendByte movf INDF,W call CalcTxCRC incf FSR,F decfsz txDummyCounter,F goto _TxHeaderLoop ;Send data byte SWAP_TO_BANK1 movf txNDB,W movwf txDummyCounter movlw tzn_txdata movwf FSR _TxDataLoop movf INDF,W call SendByte movf INDF,W call CalcTxCRC incf FSR,F decfsz txDummyCounter,F goto _TxDataLoop ;Send CRC16 byte SWAP_TO_BANK1 movf TxCRC_High,W movwf tzn_txcrc+0 movf TxCRC_Low,W movwf tzn_txcrc+1 movlw 2 movwf txDummyCounter movlw tzn_txcrc movwf FSR _TxCrcLoop movf INDF,W call SendByte incf FSR,F decfsz txDummyCounter,F goto _TxCrcLoop SWAP_TO_BANK0 bcf COM_DE ;Disable RS485 driver movf RCREG,W ;Clear USART RX buffer movf RCREG,W bsf INTCON,GIE ;Enables Global Interrupt SWAP_TO_BANK1 bsf PIE1,RCIE ;Enable the USART to receive interrupt SWAP_TO_BANK0 return ;************************************************* ; Send a byte to RS485 line ; ; Input parameters: ; ; W = Byte to send ; ; Note: The RS485 drive enable must be on ; The receiver interrupt must be disabled ;************************************************* SendByte SWAP_TO_BANK0 movwf TXREG ;Move the byte to send in the UART's TX register SWAP_TO_BANK1 WaitTxStopBit btfss TXSTA,TRMT ;Wait until the stop bit is finished goto WaitTxStopBit ;Questo ritardo serve per aspettare che effettivamente sia passato tutto ;lo stop bit sulla linea RS485. Il bit TRMT del registro TXSTA infatti indica ;solo che e' iniziata la trasmissione dello stop bit e non che questa sia finita ONE_BIT_DELAY return END