Computer Science Canada Help on Assembler Code for Robot |
| Author: | molten_rock01 [ Wed May 24, 2006 10:01 pm ] |
| Post subject: | Help on Assembler Code for Robot |
Hi. I am currently working on building a robot which follows a wall. For this, I am using two limit switches, which when turned on, make the robot reverse and change direction. So far, I've only gotten the robot to move forward, but the limit switches do not work. The following code is in Assembler and I am using Microchip's P16F684 PIC. Could you please check over this code and give me a hint why the limit switches may not be working? Thank you. title "asmWall" ; ; Robot moves forward until a signal is received from the input switch. ; When a signal from the right input switch is received, the robot reverses direction ; for 2 seconds and then turns left for 2 seconds. ; When a signal from the left input switch is received, the robot reverses direction ; for 2 seconds and then turns right for 2 seconds. ; ; Hardware Notes: ; -P16F684 running at 4MHz ; -RC0:RC1 : right motor ; -RC2:RC3 : left motor ; -RA0 : left input switch ; -RA1 : right input switch ; ; Author ; May 22, 2006 ;-------------------------------------------------------------------------- ; Setup LIST R=DEC INCLUDE "p16f684.inc" __CONFIG _FCMEN_OFF & _IESO_OFF & _BOD_OFF & _CPD_OFF & _CP_OFF & _MCLRE_ON & _PWRTE_ON & _WDT_OFF & _INTOSCIO ; Variables CBLOCK 0x20 ;Variable Declaration DlayValue:2 ;Requires 24 Bit Counter (w/ WREG) ENDC Dlay Macro Cycles variable CyclesLeft ;Keep Track of Remaining Cycles variable LargeNum CyclesLeft = Cycles local LongLoop if Cycles > 0x04FFFF0 ;Can't Handle > 83 Seconds (@ 4 MHz) error "Required Delay is longer than 'Dlay' Macro can support" endif if Cycles > 327681 ;Need Large Loop? LargeNum = CyclesLeft / 327681 movlw LargeNum movwf DlayValue + 2 ;Calculate Number of Loops LongLoop: ;Repeat for Each Loop clrf DlayValue + 1 ;Do Maximum Possible Loop Count clrf DlayValue decf DlayValue, f btfsc STATUS, Z decfsz DlayValue + 1, f goto $ - 3 decfsz DlayValue + 2, f ;Repeat Loop goto LongLoop CyclesLeft = CyclesLeft - ((LargeNum * 327681) + 1 + (LargeNum * 3)) endif ;Need Large Loop if Cycles > 14 ;Will a Loop be Required? movlw HIGH (((CyclesLeft - 3)/ 5) + 256) movwf DlayValue + 1 movlw LOW (((CyclesLeft - 3)/ 5) + 256) movwf DlayValue decf DlayValue, f ;5 Cycle Constant Delay Loop btfsc STATUS, Z decfsz DlayValue + 1, f goto $ - 3 CyclesLeft = CyclesLeft - (3 + (5 * ((CyclesLeft - 3)/ 5))) endif ;Finished with Loop Code while CyclesLeft >= 2 ;Put in 2 Instruction Cycle Delays goto $ + 1 CyclesLeft = CyclesLeft - 2 endw if CyclesLeft == 1 ;Put in the Last Required Cycle nop endif endm ; -------------------------------------------------------------------------- PAGE org 0 movlw 7 ; turn off comparators movwf CMCON0 bsf STATUS, RP0 ; all ports are digital clrf ANSEL ^ 0x080 clrf TRISC ^ 0x080 ; teach all of PORTC to be outputs movlw b'0011' ; teach RA0 and RA1 to be inputs movwf TRISA bcf STATUS, RP0 loop: ; robot moves forward ; move robot forward movlw b'1010' movwf PORTC btfss PORTA, 0 btfss PORTA, 1 call SubLSwitch btfss PORTA, 1 goto loop call SubRSwitch goto loop goto $ ; -------------------------------------------------------------------------- PAGE ; Subroutines SubLSwitch: movlw b'0101' ; reverse for 2 seconds movwf PORTC Dlay 2000000 movlw b'1001' ; turn right for 2 seconds movwf PORTC Dlay 2000000 return SubRSwitch: movlw b'0101' ; reverse for 2 seconds movwf PORTC Dlay 2000000 movlw b'0110' ; turn left for 2 seconds movwf PORTC Dlay 2000000 return end |
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| Author: | wtd [ Wed May 24, 2006 10:56 pm ] |
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Unfortunately I don't think I can offer much help, but is that PowerPC assembly? |
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| Author: | Anonymous [ Tue May 30, 2006 7:28 pm ] |
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Try to use code taggings please =) |
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