pic 16f84a

Hey Everyone,
I was hoping that someone could help me with the following program. I haven't been in school in 20 years and the economy has sent me back.And I find myself behind all the young kids.
here is what the program i supposed to do...
drive a moter with on off speed control.
there will be four pushbuttons start stop increase and decrease speed
there will be a red light to indicate power to the circuit
the moter will have four speed...stop 1/4 1/2 3/4 full
a row of red leds will indicate speed of motor
at stop all lights out
at full all lights will light
leds will change with motor speed
a green light will come on when start button is pushed

Thanks for all the help

 

Actually, when I was typing this out I was reading from a sheet. so it is no a moter its actually a 5 volt fan. But here is what I did so far, I got the fan to work and the lights come on. BUT, the sequence is flawed, it will work the way it should only once and then it stops. Here is the program any ideas?

MC6110 Motor Control 2
;Name: herb connors
;Date: 4 March 2009
include "p16f84a.inc"
__CONFIG _CP_OFF & _HS_OSC & _PWRTE_ON & _WDT_OFF
PILOT equ 0x0C ;hold the value to determine the speed of the pilot light
SPEED equ 0x0D ;hold the value representing the speed of the motor
TON equ 0x0E ;hold the value of the ON Pulse
TOFF equ 0x0F ;hold the value of the OFF Pulse

org 0x00 ;organize chip
goto Init ;goto Initialize
org 0x04 ;organize Option Register
goto ISR
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; Initialize
Init
banksel TRISA ;change bank
movlw 0xF0 ;move literal #FE into w
movwf TRISA ;set up TRIS A
movlw 0xf2 ;
movwf TRISB ;set up TRISB
movlw 0xD4 ;move Number
movwf OPTION_REG ;
movlw 0xAC ;move Number
movwf INTCON ;
banksel PORTA ;change bank
clrf TMR0 ;clear Timer Zero
movlw 0x30 ;arbitrary to slow down pilot light
movwf PILOT ;put in address 0x0C
bcf PORTB,2

Main
btfss PORTB,4 ;check start PB, skip next if not depressed
goto Start
btfss PORTB,1 ;test stop pb, skip if not depressed
goto Stop


PWM ;sets up Duty Cycle
btfss PORTB,2 ;check for green LED ON, skip next if on
goto Main ;if off go back and check switches
movfw SPEED ;move setpoint to W Reg
movwf TON ;move setpoint into TON to turn on fan
sublw 0xFF ;subtract TON from the total to get TOFF
movwf TOFF
;turn on transistor
bsf PORTB,3 ;turn on the fan
nop ;kill a cycle
decfsz TON ;Timing for Duty Cycle on
goto $-2 ;go back 2 instructions

;turn off transistor
bcf PORTB,3 ;turn off the fan
nop
decfsz TOFF ;drop TOFF, repeat until zero, include nop
goto $-2 ;TON+TOFF=255

goto Main ;go back to start of program
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Interrupt Service Routine

ISR
btfsc INTCON,T0IF ;test for TMR0 Interrupt
goto Pilot
btfsc PORTB,4
goto Speed
goto ENDISR ;quit ISR

Pilot
decfsz PILOT ;decrement PILOT, after the 0x30th TMR0
goto ENDISR ;interrupt, this section will toggle
movlw 0x01
xorwf PORTB ;pilot LED
movlw 0x30
movwf PILOT ;in between, it kicks right out of the ISR
goto ENDISR
Speed
btfss PORTB,6
goto DecSpeed ;check the slower button
btfss PORTB,7
goto IncSpeed ;check the faster button
goto ENDISR

DecSpeed
bcf STATUS,C ;set the carry bit, it will clear if result<0
rrf PORTA
movlw 0x3F ;set the amount to change
subwf SPEED ;subtract 0x3F from current speed setpoint
movfw SPEED
btfsc STATUS,C ;check to see if answer is<0
goto ENDISR ;kick out
movlw 0x01 ;if answer <0, move 0x01 into setpoint
movwf SPEED
goto ENDISR

IncSpeed
bsf STATUS,C ;set the C bit high
rlf PORTA
movlw 0x3F ;set the amount to change
addwf SPEED ;increase the current setpoint by 0x3F
movfw SPEED
btfss STATUS,C ;check to see if answer>FF
goto ENDISR ;kick out
movlw 0xFE ;if answer>FF, move FE into setpoint
movwf SPEED
goto ENDISR

Start
bsf PORTB,2 ;turn on green LED
movlw 0x7F ;start the fan at half speed
movwf SPEED
movlw 0x03
movwf PORTA ;turn on two RED LEDS
return
Stop
bcf PORTB,2 ;turn off green LED
clrf PORTA
return
ENDISR
bcf INTCON,RBIF ;clear flags
bcf INTCON,T0IF
retfie ;return from interrupt
End