; htr.a -- control of heaters

; There are 5 Heaters controlled by the DPU
N_HTRS  equ 5

; Each heater has 5 bytes associated with it:
H_STATUS   ds 1 ;  FF=inactive, 1=on, 0=off
H_SERVICE  ds 1 ;  power service number
H_CTR      ds 1 ;  decremented to zero, then state changes
H_SECS_ON  ds 1 ;  how many seconds heater should be on
H_SECS_OFF ds 1 ;  how many seconds heater should be off
H_SIZE  equ 5 ; size of array element
heater_table ds N_HTRS*H_SIZE

; The heater task checks the list of heaters
; every second.  For active heaters, it decrements
; nsecs_left; if zero, it either turns the heater
; on or off, and stores either nsecs_on or nsecs_off
; in nsecs_left

        include htr.i
        include util.i
        include pwr.i
        include task.i
        include gbl.i
        include debug.i

HTR_INIT:
; initialize heater array
        lxi h,heater_table
        mvi M,0FFh      ; inactive
        inx h
        mvi M,1         ; heater 1 - power service 1
        lxi d,H_SIZE-1
        dad d           
        mvi M,0FFh      ; inactive
        inx h
        mvi M,2         ; heater 2 - power service 2
        lxi d,H_SIZE-1
        dad d           
        mvi M,0FFh      ; inactive
        inx h
        mvi M,3         ; heater 3 - power service 3
        lxi d,H_SIZE-1
        dad d           
        mvi M,0FFh      ; inactive
        inx h
        mvi M,4         ; heater 4 - power service 4
        lxi d,H_SIZE-1
        dad d           
        mvi M,0FFh      ; inactive
        inx h
        mvi M,5         ; heater 5 - power service 5

; Start Heater Task
        lxi d,heater_task
        lxi h,GBL_HTR_STACK+stack_size
        call task_new

        ret

S0      ds 1
hcount  ds 1
 
heater_task:
sloop:  call task
        jmp sloop

       
        
HTR_SET:
; A - which heater (1..5)
; B - 1=activate, 0=deactivate
; C - ON_SECS
; D - OFF_SECS
        push psw
        push b
        push d
        push h

; Locate heater element
        lxi h,heater_table
        mvi c,N_HTRS
ll:     dcr a
        jz gotit
        lxi d,H_SIZE
        dad d
        jmp ll
gotit:
        mov a,b
        cpi 1
        jz activate
; deactivate heater
        mvi M,0FFH      ; status=deactivated
        lxi d,H_SERVICE-H_STATUS
        dad d
        mov a,M         ; power service
        call PWR_SET_OFF
        jmp xit
; Activate Heater
onsecs  ds 1
offsecs ds 1
activate:
        mov a,c
        sta onsecs
        mov a,d
        sta offsecs
;  setup heater to be turned on next cycle
        mvi M,0         ; state=off
        push h
        lxi d,H_CTR-H_STATUS
        dad d
        mvi M,1         ; counter=1 second
; set SECS_ON and SECS_OFF
        pop h
        push h
        lxi d,H_SECS_ON-H_STATUS
        dad d
        lda onsecs
        mov M,a
        pop h
        lxi d,H_SECS_OFF-H_STATUS
        dad d
        lda offsecs
        mov M,a

xit:    pop h
        pop d
        pop b
        pop psw
        ret