Subversion Repositories rtf65002

; ============================================================================
;        __
;   \\__/ o\    (C) 2013, 2014  Robert Finch, Stratford
;    \  __ /    All rights reserved.
;     \/_//     robfinch<remove>@opencores.org
;       ||
;  
;
; This source file is free software: you can redistribute it and/or modify 
; it under the terms of the GNU Lesser General Public License as published 
; by the Free Software Foundation, either version 3 of the License, or     
; (at your option) any later version.                                      
;                                                                          
; This source file is distributed in the hope that it will be useful,      
; but WITHOUT ANY WARRANTY; without even the implied warranty of           
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the            
; GNU General Public License for more details.                             
;                                                                          
; You should have received a copy of the GNU General Public License        
; along with this program.  If not, see <http://www.gnu.org/licenses/>.    
;
; ReadTemp.asm                                                                         
; ============================================================================
;
;--------------------------------------------------------------------------
; ReadTemp
;    Read and display the temperature from a DS1626 temperature sensor
; device. RTF65002 source code.
;--------------------------------------------------------------------------
DS1626_CMD      =$FFDC0300
DS1626_DAT      =$FFDC0301
; Commands
START_CNV = $51;
STOP_CNV = $22;
READ_TEMP = $AA;
READ_CONFIG = $AC;
READ_TH = $A1;
READ_TL = $A2;
WRITE_TH = $01;
WRITE_TL = $02;
WRITE_CONFIG = $0C;
POR = $54;

public ReadTemp:
        lda             CONFIGREC       ; Do we even have a temperature sensor ?
        bit             #$10
        beq             rdtmp3          ; If not, output '0.000'
rdtmp1:
        ; On power up the DS1626 interface circuit sends a power on reset (POR)
        ; command to the DS1626. Waiting here makes sure this command has been
        ; completed.
        jsr             rdt_busy_wait
        lda             #$0F                    ; 12 bits resolution, cpu mode, one-shot mode
        sta             DS1626_DAT
        lda             #WRITE_CONFIG   ; write the desired config to the device
        sta             DS1626_CMD
        jsr             rdt_busy_wait
        lda             #10
        jsr             tSleep
        lda             #0
        sta             DS1626_DAT
        lda             #START_CNV              ; issue a start conversion command
        sta             DS1626_CMD
        jsr             rdt_busy_wait
        lda             #10
        jsr             tSleep
        ; Now poll the config register to determine when the conversion has completed.
rdtmp2:
        lda             #READ_CONFIG    ; issue the READ_CONFIG command
        sta             DS1626_CMD
        jsr             rdt_busy_wait
        pha
        lda             #10                             ; Wait a bit before checking again. The conversion
        jsr             tSleep                  ; can take up to 1s to complete.
        pla
        bit             #$80                    ; test done bit
        beq             rdtmp2                  ; loop back if not done conversion
        lda             #0
        sta             DS1626_DAT              ; issue a stop conversion command
        lda             #STOP_CNV
        sta             DS1626_CMD
        jsr             rdt_busy_wait
        lda             #10
        jsr             tSleep
        lda             #READ_TEMP              ; issue the READ_TEMP command
        sta             DS1626_CMD
        jsr             rdt_busy_wait
        pha
        lda             #10
        jsr             tSleep
        pla
rdtmp4:
        jsr             CRLF
        and             #$FFF
        bit             #$800           ; check for negative temperature
        beq             rdtmp7
        sub             r1,r0,r1        ; negate the number
        and             #$FFF
        pha
        lda             #'-'            ; output a minus sign
        jsr             DisplayChar
        pla
rdtmp7:
        pha                                     ; save off value
        lsr             r1,r1,#4        ; get rid of fractional portion
        and             #$7F            ; strip off sign bit
        ldx             #3                      ; output the whole number part
        jsr             PRTNUM
        lda             #'.'            ; followed by a decimal point
        jsr             DisplayChar
        pla                                     ; get back temp value
        and             #$0F
        mul             r1,r1,#625      ; 1/16th's per degree
        ldx             #1
        jsr             PRTNUM
;       pha                                     ; save off fraction bits
;       div             r1,r1,#1000     ; calculate the first digit
;       add             #'0'
;       jsr             DisplayChar     ; output digit
;       pla                                     ; get back fractions bits
;       pha                                     ; and save again
;       div             r1,r1,#100      ; shift over to second digit
;       mod             r1,r1,#10       ; ignore high order bits
;       add             #'0'
;       jsr             DisplayChar     ; display the digit
;       pla                                     ; get back fraction
;       div             r1,r1,#10
;       mod             r1,r1,#10       ; compute low order digit
;       add             #'0'
;       jsr             DisplayChar     ; display low order digit
        jsr             CRLF
        rts
rdtmp3:
        lda             #0
        bra             rdtmp4

; Returns:
;       acc = value from data register
;
rdt_busy_wait:
        jsr             KeybdGetChar
        cmp             #CTRLC
        beq             Monitor
        lda             DS1626_DAT
        bit             #$8000
        bne             rdt_busy_wait
        rts

tSleep:
        ldx             Milliseconds
        txa
tSleep1:
        ldx             Milliseconds
        sub             r2,r2,r1
        cpx             #100
        blo             tSleep1
        rts