; Lithium Ion Battery Charger ; Charges (Raw) unprotected cells ; 12/05 Luhan Monat ; device pic12f675,intrc_osc,pwrte_on,mclre_on #include ;__config _INTRC_OSC_NOCLKOUT & _PWRTE_ON & _MCLRE_ON & _WDT_OFF & _BODEN_OFF & _CP_OFF & _CPD_OFF __config 0x01A4 radix dec cblock 20h flag: 1 temp: 1 ddata: 1 count: 1 htime: 1 ;power on time ltime: 1 ;power off time battv: 1 ;battery volts batta: 1 ;battery amps hi: 1 lo: 1 timer: 2 dfact: 3 digit: 1 dela: 1 endc #define BVOLT GPIO,1 ;battery top voltage #define BAMP GPIO,0 ;battery current sense #define LED GPIO,4 ;LED indicator #define PWR GPIO,5 ;power control #define SOUT LED #define BUG GPIO,2 org 0 goto start org 4 retfie start bsf STATUS,RP0 movlw 000011b ;set gp io directions movwf TRISIO movlw 127 movwf OSCCAL movlw 00010011b ;clk/8, ad0,1 movwf ANSEL bcf STATUS,RP0 movlw 7 movwf CMCON ;enable digital lines bsf PWR ;power off bsf LED ;led off call getvolt call getvolt movlw 70 call delay call clamp ;kill stray charge call testb ;test for battery movlw 40 call delay call charge goto chend ; loop time = 900ms ; 5 hrs = 20,000 loops charge movlw high(20000) movwf timer movlw low(20000) movwf timer+1 ___2 call getamp ;read charge current pulse movf batta,w ;result? call pwidth xorlw 0 ;check for zero btfsc STATUS,Z return ;done. call setpwr call ppulse call ppulse call ppulse call ppulse call ppulse call chktim ;count down timer btfss STATUS,Z ;done? goto ___2 ;no. goto toerr ;yes - timed out ; count down timer+1,/timer returnurn Z on done. chktim movf timer btfsc STATUS,Z decf timer+1 decf timer movf timer,w iorwf timer+1,w return testb call getvolt ;is battery present movf battv,w ;get voltage addlw 10 ;too high? btfsc STATUS,C goto hverr movf battv,w addlw 240 ;battery present? btfss STATUS,C goto nperr movf battv,w addlw 160 ;too low? btfss STATUS,C goto lverr return ; discharge stray voltage at battery clips clamp bcf BVOLT ;line low bsf STATUS,RP0 bcf BVOLT ;line is out bcf ANSEL,1 ;line is digital bcf STATUS,RP0 movlw 20 ;clear any charge call delay bsf STATUS,RP0 bsf BVOLT ;line is input bsf ANSEL,1 ;line is analog bcf STATUS,RP0 return chend movlw 1 goto hold toerr movlw 2 goto hold nperr movlw 3 goto hold lverr movlw 4 goto hold hverr movlw 5 goto hold ; turn off power and flash value in W hold bsf PWR ;power off movwf temp _2 movf temp,w movwf count _4 bcf LED movlw 25 call delay bsf LED movlw 50 call delay decfsz count goto _4 movlw 70 call delay goto _2 sign movlw 10 movwf count __2 bcf LED ;led on movlw 20 call delay bsf LED ;led off movlw 20 call delay decfsz count goto __2 return eval call getamp call serout movlw 50 call delay goto eval test bsf LED call ppulse bcf LED movlw 20 call setpwr call ppulse goto test ; set power pulse delay values via 'w' setpwr movwf htime ;high time sublw 0 ;residual time movwf ltime return ; generate power pulse ppulse movlw 250 movwf count ;set main loop count _blip movf htime,w movwf temp bcf PWR ;engage power bcf LED _b2 decfsz temp goto _b2 bsf PWR ;end power pulse bsf LED movf ltime,w movwf temp _b4 decfsz temp ;remaining time goto _b4 decfsz count goto _blip return getvolt bsf PWR ;turn off charge call volts movwf battv ;save data return getamp bcf PWR ;turn on charge call amps movwf batta ;save data bsf PWR ;turn off charge return ; read battery voltage and current amps movlw 81h ;right just, chan=0, a/d on movwf ADCON0 nop ; need to settle? bsf ADCON0,1 ;start conversion _wt btfsc ADCON0,1 ;ready? goto _wt ;no. bsf STATUS,RP0 movf ADRESL,w ;read lower quadrant bcf STATUS,RP0 return volts movlw 05h ;left just, chan=1, a/d on movwf ADCON0 bsf ADCON0,1 ;start conversion __wt btfsc ADCON0,1 ;ready? goto __wt ;no. movf ADRESH,w return delay movwf dfact+2 _dz movwf dfact+1 _dy movwf dfact _dx decfsz dfact goto _dx decfsz dfact+1 goto _dy decfsz dfact+2 goto _dz return serout movwf temp clrf count bsf count,3 bcf SOUT ;start bit nop nop nop nop _s2 nop call fbit rrf temp btfss STATUS,C bcf SOUT btfsc STATUS,C bsf SOUT decfsz count goto _s2 call fbit bsf SOUT ;stop bit call fbit call fbit return ; 9600 baud at 20mhz clock fbit movlw 136 goto fhbit hbit movlw 1 fhbit movwf dela _f2 decfsz dela goto _f2 return pwidth clrf PCLATH bsf PCLATH,0 ;100h movwf temp rrf temp rrf temp movf temp,w andlw 3fh ;devide by 4 movwf PCL org 100h _0 dt 0, 0, 0,255,255, 250,245,240 _40 dt 235,228,215,200,185, 170,155,140,125,110 _80 dt 107,103, 99, 95, 90, 85, 83, 81, 79, 77 _120 dt 60, 40, 40, 40, 40, 40, 40, 40, 40, 40 dt 40, 40, 40, 40, 40, 40, 40, 40, 40, 40 end