;######################################################## ;# Dual Unipolar Stepper Motor Controller # ;# for PIC16F876A # ;# by Hazzer123 # ;# version - 03.02.08 # ;# # ;# Stepper motor 1 connected to PORTA<3:0> # ;# Stepper motor 2 connected to PORTB<3:0> # ;# # ;# For more great robot related information and # ;# discussion visit www.societyofrobots.com # ;######################################################## LIST p=16F876A ; PIC16F844 is the target processor #include "P16F876A.INC" #define DIR 0 #define MOVING 1 #define STATE 2 cblock 0x20 ; Temporary storage d1 d2 d3 MOTOR1CON MOTOR2CON MOTOR1SPEED MOTOR1SPEEDBUFF MOTOR2SPEED MOTOR2SPEEDBUFF MOTOR1STEPNUM MOTOR2STEPNUM counter endc org 0 goto Start ;INTERRUPT ROUTINE========================================== org 0x04 BTFSC INTCON,TMR0IF CALL timer_0_overflow BTFSC PIR1,TMR1IF CALL timer_1_overflow RETFIE ;START====================================================== Start BCF STATUS,RP0 BCF STATUS,RP1 ;Page 0 ;PORTS====================================================== BSF STATUS,RP0 MOVLW 0x06 ;Set PORTA to digital MOVWF ADCON1 MOVLW b'11110000' ;RA0-3 outputs to ULN2003 for motor 1 MOVWF TRISA MOVLW b'11110000' ;RB0-3 outputs to ULN2003 for motor 2 MOVWF TRISB MOVLW b'00011000' ;RC3 and RC4 inputs for I2C slave mode MOVWF TRISC BCF STATUS,RP0 CLRF PORTA ;Clear ports CLRF PORTB CLRF PORTC ;TIMER0====================================================== BSF STATUS,RP0 MOVLW b'11000100' ;TMR0 on, 1:32 prescaler MOVWF OPTION_REG BCF STATUS,RP0 BCF INTCON,TMR0IF ;Clear Timer 0 flag bit BSF INTCON,TMR0IE ;Enable Timer0 tnterrupts ;TIMER1====================================================== MOVLW b'00000001' ;TMR1 on, no prescaler MOVWF T1CON BCF PIR1,TMR1IF ;Clear Timer 1 flag bit BSF STATUS,RP0 BSF PIE1,TMR1IE ;Enable Timer 1 interrupts BCF STATUS,RP0 ;INITIALISE VARIABLES========================================= MOVLW d'10' ;Initial time between half-steps is 10ms - MOTORXSPEED doesnt really hold a value for speed, but the time between sequential half-steps MOVWF MOTOR1SPEED MOVWF MOTOR1SPEEDBUFF MOVLW d'10' MOVWF MOTOR2SPEED MOVWF MOTOR2SPEEDBUFF BSF MOTOR1CON,DIR ;Motor 1 is default forward BCF MOTOR1CON,MOVING;Motor 1 is default not moving BCF MOTOR1CON,STATE ;Motor 1 is default turned off. BSF MOTOR2CON,DIR BCF MOTOR2CON,MOVING BCF MOTOR2CON,STATE MOVLW d'1' MOVWF MOTOR1STEPNUM ;Both start with stepnum value 1 MOVWF MOTOR2STEPNUM clrf counter ;clear counter ;INTERRUPTS=================================================== BSF INTCON,TMR0IE ;Enable timer0 interrupt BSF INTCON,PEIE ;Enable all peripheral interrupts BSF INTCON,GIE ;Enable all interrupts ;MAIN========================================================= BSF MOTOR1CON,STATE ;Turn motors on and moving BSF MOTOR2CON,STATE BSF MOTOR1CON,MOVING BSF MOTOR2CON,MOVING Loop incf counter,f movf counter,w call table_lookup ;Find the speed for motor 1 in the table lookup movwf MOTOR1SPEED incf counter,f movf counter,w call table_lookup ;Find the speed for motor 2 in the table lookup movwf MOTOR2SPEED call delay_1s ;Delay, to allow the motors to turn. goto Loop table_lookup addwf PCL nop retlw 6 ;Speed of motor 1 in sequence. (Go forward) retlw 6 ;Speed of motor 2 in sequence. retlw 6 ;Second speed of motor 1 in sequence. (Turn left) retlw 10 ;Second speed of motor 2 in sequence.... retlw 6 ;(Go forward) retlw 6 retlw 10 ;(Turn right) retlw 6 movlw d'1' ;If counter is too high, reset and do table_lookup again movwf counter goto table_lookup RETURN timer_0_overflow BCF INTCON,TMR0IF ;Clear interrupt flag bit movlw 0x09 ;Small inline delay, to make time between interrupts 1ms movwf d1 delay_tmr0_0 decfsz d1, f goto delay_tmr0_0 goto $+1 MOVLW d'101' ;Offset the timer 0, in order to get 1ms interrupts MOVWF TMR0 DECFSZ MOTOR1SPEEDBUFF,F ;Count down the milliseconds until the next half-step RETURN BTFSS MOTOR1CON,STATE ;If the motor is turned off, clear porta CLRF PORTA BTFSS MOTOR1CON,MOVING ;Return before half-step routine if not moving RETURN BTFSC MOTOR1CON,DIR goto aforwards BTFSS MOTOR1CON,DIR goto abackwards aforwards INCF MOTOR1STEPNUM,F ;Going forward so increment step num. MOVF MOTOR1STEPNUM,W ;Check if step num has gone to 9 (too far) SUBLW d'9' BTFSS STATUS,Z GOTO acarry_on MOVLW d'1' ;If counter = 9, loop back and set stepnum to 1. MOVWF MOTOR1STEPNUM GOTO acarry_on abackwards DECFSZ MOTOR1STEPNUM,F ;Going backwards so decrement step num GOTO acarry_on ;If not zero, carry on. MOVLW d'8' MOVWF MOTOR1STEPNUM ;If zero, then loop around and set stepnum to 8 GOTO acarry_on acarry_on movf MOTOR1STEPNUM,W call step_table ;Find corresponding PORT state for step num BTFSC MOTOR1CON,STATE MOVWF PORTA ;If motor is turned on, move port state to PORTA BTFSS MOTOR1CON,STATE CLRF PORTA ;If motor is turned off, clear PORTA MOVF MOTOR1SPEED,W ;Load the motor speed into a buffer for counting down. MOVWF MOTOR1SPEEDBUFF RETURN timer_1_overflow BCF PIR1,TMR1IF ;Basically the same as timer_0_overflow MOVLW b'11101100' ;These values make time between interrupt 1ms MOVWF TMR1H MOVLW b'10101001' MOVWF TMR1L DECFSZ MOTOR2SPEEDBUFF,F RETURN BTFSS MOTOR2CON,STATE CLRF PORTB BTFSS MOTOR2CON,MOVING RETURN BTFSC MOTOR2CON,DIR goto bforwards BTFSS MOTOR2CON,DIR goto bbackwards bforwards DECFSZ MOTOR2STEPNUM,F GOTO bcarry_on MOVLW d'8' MOVWF MOTOR2STEPNUM GOTO bcarry_on bbackwards INCF MOTOR2STEPNUM,F MOVF MOTOR2STEPNUM,W SUBLW d'9' BTFSS STATUS,Z GOTO bcarry_on MOVLW d'1' MOVWF MOTOR2STEPNUM GOTO bcarry_on bcarry_on movf MOTOR2STEPNUM,W call step_table BTFSC MOTOR2CON,STATE MOVWF PORTB BTFSS MOTOR2CON,STATE CLRF PORTB MOVF MOTOR2SPEED,W MOVWF MOTOR2SPEEDBUFF RETURN step_table addwf PCL retlw b'0000' retlw b'1001' retlw b'1000' retlw b'1010' retlw b'0010' retlw b'0110' retlw b'0100' retlw b'0101' retlw b'0001' RETURN ; Delay = 0.1 seconds ; Clock frequency = 20 MHz ; Actual delay = 0.1 seconds = 500000 cycles ; Error = 0 % delay_100ms ;499994 cycles movlw 0x03 movwf d1 movlw 0x18 movwf d2 movlw 0x02 movwf d3 delay_100ms_0 decfsz d1, f goto $+2 decfsz d2, f goto $+2 decfsz d3, f goto delay_100ms_0 ;2 cycles goto $+1 ;4 cycles (including call) return ; Delay = 1 seconds ; Clock frequency = 20 MHz ; Actual delay = 1 seconds = 5000000 cycles ; Error = 0 % delay_1s ;4999993 cycles movlw 0x2C movwf d1 movlw 0xE7 movwf d2 movlw 0x0B movwf d3 delay_1s_0 decfsz d1, f goto $+2 decfsz d2, f goto $+2 decfsz d3, f goto delay_1s_0 ;3 cycles goto $+1 nop ;4 cycles (including call) return ; Delay = 0.001 seconds ; Clock frequency = 20 MHz ; Actual delay = 0.001 seconds = 5000 cycles ; Error = 0 % delay_wms ;4993 cycles movwf d3 delay_1ms movlw 0xE6 movwf d1 movlw 0x04 movwf d2 delay_1ms_0 decfsz d1, f goto $+2 decfsz d2, f goto delay_1ms_0 decfsz d3,f goto delay_1ms ;3 cycles goto $+1 nop ;4 cycles (including call) return delay_quartturn ;3249993 cycles movlw 0xAC movwf d1 movlw 0x30 movwf d2 movlw 0x08 movwf d3 delay_quartturn_0 decfsz d1, f goto $+2 decfsz d2, f goto $+2 decfsz d3, f goto delay_quartturn_0 ;3 cycles goto $+1 nop ;4 cycles (including call) return end