I2c Tool
I2c search circuit
I2c search circuit
This programm can be used to search the i2c device address from a i2c bus. The i2c address it's displayed on portb before transmission. The middle leds are blinking when the current address has no acknowlege.
;=======iic_tool / Version 2.0====================16/08/03== ; cauta pe i2c adrese de lcd ; ra0,ra1 sdata,sclock ; rb0 to rb7 ; internal clock ; standard crystal 4.000 MHz XT - 1us pe instructiune ; http://www.module.ro ;------------------------------------------------------------ list p=16f84A;f=inhx8m _CP_OFF equ H'3FFF' ;code protect off _PWRTE_ON equ H'3FFF' ;Power on timer on _WDT_OFF equ H'3FFB' ;watch dog timer off _XT_OSC equ H'3FFD' ;crystal oscillator __CONFIG _CP_OFF & _PWRTE_ON & _WDT_OFF & _XT_OSC ;------------------------------------------------------------ ; cpu init status equ 03 porta equ 05 portb equ 06 count1 equ 0C count2 equ 0D count3 equ 0E transo equ 0F count4 equ 10 count5 equ 11 count6 equ 12 trisa equ 85 trisb equ 86 #DEFINE sclk porta,1 #DEFINE sdta porta,0 ;------------------------------------------------------------ ; bit init rp0 equ 5 w equ 0 f equ 1 ;------------------------------------------------------------ org 0 ; ;------------------------------------------------------------ init bsf status,rp0 ;switch to bank 1 movlw 0 ;outputs movwf trisb bcf status,rp0 ;switch back to bank 0 movlw 0 movwf portb ;*************************************************** start movlw 0xFF movwf portb call pause ;*************************************************** scrie movlw 0x80 ; iic start seeking address (70 to 80h for lcd screen) movwf transo act bsf status,rp0 ;ouput port a movlw 0 ;outputs movwf trisa bcf status,rp0 ;switch back to bank 0 movlw 0 movwf porta ;*************************************************** movlw 0x00 movwf portb ;*************************************************** bsf sdta ; start condition module bcf sclk call pause bsf sclk call pause bcf sdta ; start call pause bcf sclk call pause ;*************************************************** movf transo,w movwf portb call pausa movlw 0x00 movwf portb call pause bcf sclk call pause bcf sclk ; varsa call pause btfsc transo,7 ;bit0(MSB) bsf sdta btfss transo,7 bcf sdta call pause bsf sclk call pause bcf sclk call pause btfsc transo,6 ;bit1 bsf sdta btfss transo,6 bcf sdta call pause bsf sclk call pause bcf sclk call pause btfsc transo,5 ;bit2 bsf sdta btfss transo,5 bcf sdta call pause bsf sclk call pause bcf sclk call pause btfsc transo,4 ;bit3 bsf sdta btfss transo,4 bcf sdta call pause bsf sclk call pause bcf sclk call pause btfsc transo,3 ;bit4 bsf sdta btfss transo,3 bcf sdta call pause bsf sclk call pause bcf sclk call pause btfsc transo,2 ;bit5 bsf sdta btfss transo,2 bcf sdta call pause bsf sclk call pause bcf sclk call pause btfsc transo,1 ;bit6 bsf sdta btfss transo,1 bcf sdta call pause bsf sclk call pause bcf sclk call pause btfsc transo,0 ;bit7(LSB) bsf sdta btfss transo,0 bcf sdta call pause bsf sclk call pause bcf sclk call pause ;*************************************************** bsf status,rp0 ;porta input movlw 0x01 ;input movwf trisa ; set sda as input bcf status,rp0 ;switch back to bank 0 ;*************************************************** call antwt ; response from iic device call pause call sout call ahalt decfsz transo,f goto act nop homa goto homa ;*************************************************** sout bsf status,rp0 ;switch to bank 1 movlw 0 ;outputs movwf trisa bcf status,rp0 ;switch back to bank 0 movlw 0 movwf porta retlw 00 ;*************************************************** ahalt bcf sdta ; stop condition module call pause bsf sclk call pause bsf sdta ; comanda stop call pause bcf sclk call pause retlw 00 ;*************************************************** antwt movlw 0x04 ; wait for a ack movwf count4 bsf sclk call pause ackts btfss sdta ;sda=0 ? goto eprok decfsz count4,f goto ackts call fails eprok bcf sclk retlw 00 ;*************************************************** fails bsf portb,2 ; middle leds blinking when not ack bsf portb,3 call pause bcf portb,2 bcf portb,3 call pause bsf portb,2 bsf portb,3 call pause bcf portb,2 bcf portb,3 call pause retlw 00 ;*************************************************** pause movlw 0x01 movwf count3 d3 movlw 0xF0 movwf count1 d1 movlw 0xF0 movwf count2 d2 decfsz count2,f goto d2 decfsz count1,f goto d1 decfsz count3,f goto d3 retlw 00 ;*************************************************** pausa movlw 0x06 movwf count3 r3 movlw 0xF0 movwf count1 r1 movlw 0xF0 movwf count2 r2 decfsz count2,f goto r2 decfsz count1,f goto r1 decfsz count3,f goto r3 retlw 00 ;------------------------------------------------------------ end ;============================================================
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