Post by thread:[SX] Problems with WKPND

In SX Microcontrollers, SX/B Compiler and SX-Key Tool, RS_Jim wrote:I have been working on a Tacometer project for a while now and seem to have hit the wall. I am running the Tac under an interupt along with a counter timer that I use to measure the lapse time between passes of the tac stripe on an optical sensor. I am currently using an external comparitor just to give me an absolutly clean tac pulse. This has been confirmed by scope. Here is the interupt code: ' ========================================================================= ' ' File...... interupt_inc_a.SXB ' Purpose... INterupts for tac Project. ' Author.... Jim Meek ' E-mail.... ' Started... ' Updated...June 3. 2009 to include tac skip function. ' Updated....June 14, 2009 to use edge detection for tac ' ========================================================================= ' ------------------------------------------------------------------------- ' Program Description ' ------------------------------------------------------------------------- ' Runs tacometer accelerometer pwm under intrupts ' ------------------------------------------------------------------------- ' INTERRUPT ' ------------------------------------------------------------------------- ISR_Start: ASM Bank Timing mov w, #230 ; for it - 234_000 'mov w,#100 ;for int=100,000 ' mov w, #10 ;for int = 10,000 dec usec snz mov usec,w ;reload microsec timer snz ' SETB AccRun 'tells the Accelerameter to colllect data ' Snz inc Msec ;every millisec mov w, #10 ;was 10 mov w, MSec-w ;Z if MSec = 10 snz clr Msec SNZ SETB Trigger snz inc Hsec ';every 1/100 sec for 1 sec mov W,#$06 ADD Hsec,W SB DC Sub Hsec,w mov w, #$A0 'Hex equivalant of 100 mov w, HSec-w ;Z if HSec = 100 snz clr Hsec snz inc sec ; every sec mov W,#$06 ADD sec,W SB DC Sub sec,w mov w, #$60 mov w, Sec,-w ; Z if Sec = 60 snz clr sec clrb Trigger 'BANK 0 ENDASM ASM BANK txSerial ' (1) TEST txCount ' (1) transmitting now? JZ TX_Buffer ' (2/4) if txCount = 0, no DEC txDivide ' (1) update bit timer JNZ TX_Done ' (2/4) time for new bit? MOV txDivide, #Baud1x0 ' (2) yes, reload timer STC ' (1) set for stop bit RR txHi ' (1) rotate TX char buf RR txLo ' (1) DEC txCount ' (1) update the bit count MOVB TX, txLo.6 ' (4) output the bit JMP TX_Done ' (3) TX_Buffer: TEST txBufCnt ' (1) anything in buffer? JZ TX_Done ' (2/4) exit if empty MOV W, #txBuf ' (2) point to buffer tail ADD W, txTail ' (1) MOV FSR, W ' (1) MOV txHi, IND ' (2) move byte to TX reg CLR txLo ' (1) clear for start bit MOV txCount, #10 ' (2) start + 8 + 1 stop INC txTail ' (1) update tail pointer CLRB txTail.3 ' (1) keep 0..7 DEC txBufCnt ' (1) update buffer count TX_Done: ' BANK __DEFAULT ' (1) ENDASM 'Tachometer: ASM BANK timing jb TInhib,Tacexit ' Tinhib prevents loading time values from 2 diffenent periods Mode WKPNDB CLR W MOV !RB,W AND W,#%0001_0000 SNZ 'jmp if no bit jmp TacExit inc TacTmp_lsb 'test how often we get a hit every revolution. SNZ inc TacTmp_msb mov tac0_lsb,tac1_lsb 'save previous pass mov tac0_msb,tac1_msb mov tac1_lsb,Tac2_lsb 'save last pass mov tac1_msb,Tac2_msb Mov tac2_lsb,TacTime_lsb Mov Tac2_msb,TacTime_msb mov TacTime_lsb,hsec 'store current time mov TacTime_MSB,SEC SETB tDone TacExit: ENDASM ' BANK 0 'reset bank if ending ISR ISR_Exit: BANK 0 RETURNINT ' {cycles} The program code looks like this: Start: ASM MODE WKEDB MOV W,#%11101110 MOV !RB,W MODE WKPNDB CLR W MOV !RB,W ' MODE CMP ' MOV !rb,#CompEn ENDASM PLP_A = %0000_0000 PLP_B = %0000_0000 PLP_C = %0000_0000 TX = 1 DELAY_MS 5 Main: LCD_CCHAR CC0 TX_Byte LCDCls Delay_MS 250 TX_BYTE LCDBlON TX_BYTE POS1 TX_STR pPwmWId TX_BYTE POS3 TX_STR pTacResult pwmwid = $15 tmpW1 = 0 BANK @ MTRARRAY \SETB motorOn Put @m1Speed,15 BANK __DEFAULT DELAY_MS 2000 \clrb Tdone do while pwmwid < $100 tmpW1 = 0 do while tmpw1 = 0 tmpW1 = TAC_RESULT loop TacResult = tmpW1 TX_BYTE POS2 PRINT_HEX_STR pwmwid TX_BYTE POS4 PRINT_HEX_STR TacResult TX_BYTE POS5 BANK @Timing __wParam12 = TimeWord PRINT_HEX_STR __wparam12 TX_BYTE POS7 BANK @Timing __wparam12 = TacTmp PRINT_HEX_STR __wparam12 TacTmp = 0 BANK __default tmpW2 = 5 pwmwid = BCD_Word_ADD pwmwid,tmpW2 BANK @ MTRARRAY m1Speed = m1speed + 5 BANK __default Delay_MS 2000 Loop put @ m1speed,0 TX_Byte LCDCls Delay_MS 250 TX_BYTE LCDBlON TX_BYTE POS1 TX_STR pPwmWId TX_BYTE POS3 TX_STR pTacResult DELAY_MS 250 goto main sub print hex encapsulates the HEX_str comand and sends it a numeric sting printing command FUNC TAC_RESULT __wparam12 =0 \ SB Tdone \ jmp txit \ SETB TInhib 'prevent interupt during this measurement Bank @timing __wparam34 = Tac2 __wparam12 = TacTime if Tac2 > TacTime Then __wparam12 = __wparam12 + $6000 'sec rolled over Endif \clrb TInhib 'interupt wont hurt now. ' __wparam12 = tacTime - Tac2 __wparam12 = BCD_WORD_SUB __wparam12,__wparam34 ' Tac0 = Tac1 'handled in isr ' Tac1 = Tac2 ' Tac2 = TacTime \clrb TDone 'wait for new info Txit: 'Txit1: Bank 0 tmpW1 = __wparam12 RETURN tmpW1 I put the increment of TacTmp in the ISR just to see how many times the tac was being updated between passes of the main program. The time between pulses from the tac are between 500 and 1100 MS. The readout I am getting on the lcd display usually reads 1. When the motor is turning its slowest I may get .11 seconds where I should get over a second. Any Ideas why the tac is updating more often than once per revolution? Compiled under 2.00.26 assembled using new SX IDE 3.0 ANy and all ideas are invited.

---------- End of Message ---------- You can view the post on-line at: http://forums.parallax.com/forums/default.aspx?f=7&p=1&m=367347 Need assistance? Send an email to the Forum Administrator at forumadmin@parallax.com The Parallax Forums are powered by dotNetBB Forums, copyright 2002-2009 (http://www.dotNetBB.com)