Return-Path: robot-board@oberon.com Received: by media.mit.edu (5.57/DA1.0.4.amt) id AA21075; Fri, 23 Jul 93 12:23:29 -0400 Received: from ([127.0.0.1]) by oberon.com (4.1/SMI-4.1_Armado.MX) id AA21963; Fri, 23 Jul 93 12:22:55 EDT Date: Fri, 23 Jul 93 12:22:54 EDT Message-Id: <9307231541.AA11769@bullfrog.nscee.edu.nscnet> Comment: Discussions of Robot controller boards Originator: robot-board@oberon.com Errors-To: gkulosa@oberon.com Reply-To: "David A. Ence" Sender: robot-board@oberon.com Version: 5.5 -- Copyright (c) 1991/92, Anastasios Kotsikonas From: "David A. Ence" To: Multiple recipients of list Subject: STEPPER CODE Ok. Here it is. I don't clame to be the best assembly coder so this code could be looked over and mabey optimized a bit. I hope it will help you guys and what you are doing. I still am seeking someone to talk to about the SPI subsystem. I would like any and all feed back on this. Also any changes that improved the code. Thank you. THE HARDWARE: The stepper I have been using is a 15 degree 12 Volt bipolor. One may hook up one stepper to port1 and port2, and another to port3 and port4. Thus only 2 steppers may be hooked up to one miniboard at one time. If one hooks up a stepper to port1 and port2, connect one coil of the stepper to each port. Do the same to connect a stepper to port3 and port4. THE SOFTWARE: As one may notice, the routine is implemented with interupts. each time a timer interrupt fires one step is made. One may change the time between steps by changing the lengh varible. This is done in the "stepper" subroutine after the pointers and direction mask are cleared. clr ptr1 clr ptr2 clr stpctrl ldd #$0000 <-------HERE Change This Value std lengh The routine "stepper" is called after 2 values have been pushed onto the stack. For an example I left the routine "main" in the code so you could see what I'm talking about. The first value that is pushed onto the stack is a -24. Since my stepper is a 15 degree stepper, It will make one full revolution. Since the value is negitive it will go CounterClockWise. This value is for the stepper attached to port1 and port2. The second value is 24. It is for the stepper connected to port3 and port4. The stepper will turn ClockWise one full revolution. If you need any help drop me a line. Have fun stepping. Later, David A. Ence ence@nye.nscee.edu -------------------------------cut here----------------------------- *----------------------------------------------------- * Title: step.asm * Author: David A. Ence * ence@nye.nscee.edu * Date:7/3/93 *------------------------------------------------------ RESETINIT equ $fe OC2I equ $e6 BASE equ $1000 TCTL1 equ $1020 TCNT equ $100e TOC2 equ $1018 TFLG1 equ $1023 TMSK1 equ $1022 TMSK2 equ $1024 PORTB equ $1004 org $00 ptr1 rmb 1 ;pointer into steptab1 ptr2 rmb 1 ;pointer into steptab2 stpctrl rmb 1 ;direction mask cnt1 rmb 1 ;holds number of steps for stepper1 cnt2 rmb 1 ;holds number of steps for stepper2 lengh fdb 2 ;Time between steps org $ff00+RESETINIT fdb main ;set interrupt vector for restart org $ff00+OC2I fdb stepi ;set interrupt vector for OC2I org $f800 ;start of eeprom *---------------------------------------------------------- * Table for step sequence *---------------------------------------------------------- steptab1 fcb %00110011 ;red red fcb %00110010 ;red grn fcb %00110000 ;grn grn fcb %00110001 ;grn red steptab2 fcb %11001100 ;red red fcb %11001000 ;red grn fcb %11000000 ;grn grn fcb %11000100 ;grn red *----------------------------------------------- * Here we push 2 values onto the stack * a neg value for ccw * a pos value for cw *----------------------------------------------- main equ * lds #$ff lda #-24 ;change this val for stepper1 psha lda #24 ;change this val for stepper2 psha bsr stepper ;call the routine pula pula done bra done *------------------------------------------------- stepper equ * bra start start psha pshb pshy clr ptr1 ;clear the pointers clr ptr2 clr stpctrl ;clear direction mask ldd #$0000 ;change this value to change speed of steps std lengh tsy ldaa 7,y ;get values off stack staa cnt1 ldaa 6,y staa cnt2 ldaa cnt1 tsta bmi ovr1 bset stpctrl $01 ;set direction bits in stctrl mask ovr1 ldaa cnt2 tsta bmi ovr2 bset stpctrl $02 ovr2 ldx #BASE bset TCTL1,x $C0 ;when interr occur drive OC2 high ldd TCNT,x ;avoid premature cmp addd lengh std TOC2,x ;store to TOC2 ldaa #$40 staa TFLG1,x ;Set up flag staa TMSK1,x ;Enable Timer2 interrupt cli ck lda cnt1 ;loop til cnt1 & cnt2 == 0 ora cnt2 tsta bne ck bclr TMSK1,x $bf puly pulb pula rts *---------------------------------------- stepi equ * ldx #BASE ldd lengh ;put back to lengh Add lengh to TOC2 addd TOC2,x ;to set up for std TOC2,x ;next step. bclr TFLG1,x,$bf ;Clear interrupt flag. clra ldab cnt1 ;if cnt1 ==0 tstb beq stpr2 ;then ck stepper2 else step stepper1 ldy #steptab1 ;get bit pattern ldab ptr1 ;for stepper1 to be stored in PORTB aby ora 0,y brclr stpctrl $01 cw1 ;update pointers and dec cnt1 ;counter for stepper1 depending on inc ptr1 ;direction. cmpb #3 bne stpr2 clr ptr1 bra stpr2 cw1 dec ptr1 inc cnt1 tstb bne stpr2 ldab #3 stab ptr1 stpr2 ldab cnt2 ;if cnt2 == 0 tstb beq dostep ;then perform the step ldy #steptab2 ;get step pattern for stepper2 ldab ptr2 aby ora 0,y brclr stpctrl $02 cw2 ;update pointers dec cnt2 ;and counters inc ptr2 ;for stepper2 depending on direction. cmpb #3 bne dostep clr ptr2 bra dostep cw2 dec ptr2 inc cnt2 tstb bne dostep ldab #3 stab ptr2 dostep staa PORTB,x ;do the step rti