Witam,
znalazłem źródło Kolegi
ZS1AYJ.
Czy ktoś z Kolegów mógłby pomóc i wskazać zmiany dla 103,5Hz?
Tyle wiem: 103,5 / 0,00192273 = 53830 = ???
Zmienić chyba trzeba przedostatnią linię kodu ?.
Potrzebuję do swojego Radmora 3001 hi hi.
Pozdrawiam
Andrzej
Kod:
; TERRY COTTON ZS1AYJ - VERSION 1.0 JANUARY 2007
; USES PIC12F675 AS A DDS GENERATOR. PHASE ACCUMULATOR IS 24 BITS
; AND PHASE INCREMENT is 16 BITS. GPIO 0-2 IS THE 3 BIT OUPUT TO
; THE CRUDE RESISTOR DAC.
; THIS CODE USES A 256 BYTE (8 BIT) LOOKUP TABLE BUT ONLY A
; 3 BIT OUTPUT VALUE. THIS IS FOR VERSATILITY. IT ALLOWS UP
; TO 8 BIT OUTPUT WITH A DIFFERENT MICRO AND A SIMPLE CHANGE
; TO THE TABLE DATA.
; THE CODE IS 'HARD WIRED" TO PRODUCE 88.5 HZ BUT ANY OTHER
; FREQUENCY CAN BE PRODUCED WITH A DIFFERENT PHASE INCREMENT.
; SEE THE EXPLANATORY TEXT BELOW AND THE 2ND LAST LINE OF
; CODE FOR THE PRESET VALUE WHICH IS STORED IN EEPROM
;*********************************************************************
include "P12F675.inc"
list p=12F675, r=dec, st=on ;radix 10, produce symbol table
;code protection off
;power-on timer on
;watchdog timer off
;HS Oscillator
__config _CP_OFF & _PWRTE_ON & _WDT_OFF & _XT_OSC
#DEFINE BANK0 BCF STATUS,RP0 ;Select register Bank 0.
#DEFINE BANK1 BSF STATUS,RP0 ;Select register Bank 1.
gpio equ 5
; General Purpose register definitions
;**************************************************************
CBLOCK 020h
PHASEACC0 ; lsb of phase accumulator
PHASEACC1
PHASEACC2 ; msb of phase accumulator
PHASEINCR0 ; phase increment lsb
PHASEINCR1 ; phase increment msb
TEMPSTORE ; temp storage for table lookup routine
ENDC
;**************************************************************
ORG 0 ; Reset Vector address
GOTO 5 ; go to PIC address location 5
ORG 4 ; Interrupt Vector address
GOTO 5 ; go to PIC address location 5
ORG 5 ; Start of Program Memory at location 5
clrf INTCON ; all interrupts disabled
clrf GPIO
movlw 7 ; set GP0-2 as digital I/O
movwf CMCON
BANK1
clrf ANSEL ; Digital I/O
movlw 038h
movwf TRISIO ; GP0-2 as output
clrf OPTION_REG ; (no options required)
clrf PIE1 ; disable all peripheral ints
BANK0
; initialise phase accumulator
clrf phaseacc1
clrf phaseacc0
clrf phaseacc2
;***************************************************
; The DDS loop below takes 31uS to execute with 4 MHz crystal
; loop frequency is therefore 1000000/31 = 32258.06 Hz
;
; Phase resolution = loop frequency/2^24 which is
; the maximum value of a 24 bit phase accumulator 16777216 decimal)
;
; Phase resolution 32258.06 / 16777216 = 0.00192273 Hz
; initialise phase increment for 88.5
; The required phase increment = output frequency / phase resolution
; 88.5 / 0.00192273 = 46028 = B3CCh
;***************************************************
; In this design only 2 bytes are used to store the phase
; increment. This is to maximise the loop frequency and hence
; minimise the phase resolution. This limits the range of
; frequencies which can be generated to the range .0019 Hz to
; 127 Hz
;
; Instead of hard-coding the phase increment calculated above,
; it is instead stored in EEPROM as 2 hexadecimal digits.
; This is to make a change of frequency a simpler process.
; Instead of re-assembling the source code, the 2 bytes at the
; end of the hex file can simply be be edited with a text editor
; to change the phase increment to the required value.
;
; Read the 2 phase increment bytes from EEPROM. In the case of
; the 88.5 Hz calculation above, the first byte 1 = B3h and
; byte 2 = CCh
;***************************************************
movlw 0
call EEPROMread ; read first byte
movwf phaseincr1
movlw 1
call EEPROMread ; read second byte
movwf phaseincr0
;***************************************************
; START OF DDS LOOP. NOTE THAT THE NOP'S ARE TO GIVE
; A CONSTANT 31uS LOOP TIME REGARDLESS OF WHETHER THERE
; ARE 0, 1 or 2 CARRYS
;***************************************************
main
movf phaseincr0,w ;Add byte 0
addwf phaseacc0,f
bc carry1 ;jump if carry into byte 1
nop
nop
nop
nop
nop
nop
b addbyte2
carry1 movlw 1
addwf phaseacc1,f
bc carry2
nop
b addbyte2
carry2
movlw 1
addwf phaseacc2,f
addbyte2
movf phaseincr1,w ;Add byte phaseincr1
addwf phaseacc1,f ;to phasecc1
bc carry3 ;jump if carry into byte 2
nop
b lookup
carry3 movlw 1
addwf phaseacc2,f
;***************************************************
; THE ABOVE CODE HAS ADDED THE PHASE INCREMENT TO THE
; PHASE ACCUMULATOR. NOW USE THE VALUE OF THE MOST
; SIGNIFICANT 8 BITS OF THE PHASE ACCUMULATOR TO ADDRESS
; A 256 BYTE TABLE WHICH CONTAINS THE DIGITAL OUTPUT TO
; BE PRESENTED TO THE DAC AT THIS PHASE OF THE SINE WAVE
;***************************************************
lookup
call tablesub
movwf gpio ;PRESENT VALUE ON GPIO 0-2
b main
;***************************************************
; END OF DDS LOOP
;***************************************************
; lookup table hard coded as 256 bytes max starting at 100h
TABLESUB movlw 1
movwf pclath ;set pclath=1
movf phaseacc2,w
movwf pcl ;change pcl to execute jump
org 100h
; The lookup table values are calculated for 3 bit digital
SINE
retlw 4
retlw 4
retlw 4
retlw 4
retlw 4
retlw 4
retlw 4
retlw 4
retlw 4
retlw 4
retlw 4
retlw 5
retlw 5
retlw 5
retlw 5
retlw 5
retlw 5
retlw 5
retlw 5
retlw 5
retlw 5
retlw 5
retlw 6
retlw 6
retlw 6
retlw 6
retlw 6
retlw 6
retlw 6
retlw 6
retlw 6
retlw 6
retlw 6
retlw 6
retlw 6
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 7
retlw 6
retlw 6
retlw 6
retlw 6
retlw 6
retlw 6
retlw 6
retlw 6
retlw 6
retlw 6
retlw 6
retlw 6
retlw 6
retlw 5
retlw 5
retlw 5
retlw 5
retlw 5
retlw 5
retlw 5
retlw 5
retlw 5
retlw 5
retlw 5
retlw 4
retlw 4
retlw 4
retlw 4
retlw 4
retlw 4
retlw 4
retlw 4
retlw 4
retlw 4
retlw 4
retlw 3
retlw 3
retlw 3
retlw 3
retlw 3
retlw 3
retlw 3
retlw 3
retlw 3
retlw 3
retlw 2
retlw 2
retlw 2
retlw 2
retlw 2
retlw 2
retlw 2
retlw 2
retlw 2
retlw 2
retlw 2
retlw 1
retlw 1
retlw 1
retlw 1
retlw 1
retlw 1
retlw 1
retlw 1
retlw 1
retlw 1
retlw 1
retlw 1
retlw 1
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 0
retlw 1
retlw 1
retlw 1
retlw 1
retlw 1
retlw 1
retlw 1
retlw 1
retlw 1
retlw 1
retlw 1
retlw 1
retlw 1
retlw 2
retlw 2
retlw 2
retlw 2
retlw 2
retlw 2
retlw 2
retlw 2
retlw 2
retlw 2
retlw 2
retlw 3
retlw 3
retlw 3
retlw 3
retlw 3
retlw 3
retlw 3
retlw 3
retlw 3
retlw 3
;*************************************************
; Read a byte from EEPROM. Enter with W =address to be read
; Exit with W = data read from that address
;*************************************************
EEPROMread
Bank1
movwf EEADR ;Address to read
bsf EECON1,RD ;EE Read
movf EEDATA,W ;Move data to W
bank0
return
;*************************************************
; Preset first 2 bytes of EEPROM to the required
; phase increment. These will be B3CCh for 88.5 Hz
;*************************************************
org 2100h
de 0b3h,0cch ;phase increment
end
