; ******* bitsc1 ***** ESC for toy car Rx ; This design will work only when the "UP" and "DOWN" ; inputs are connected to points on the Rx that are ; positive when the Tx button is NOT pushed, and turn ; negative WHEN the Tx button is pushed. ; This version allows the user to set an automatic ; motor cut off feature to the desired time delay in ; increments of 15 sec. This is provided for safety ; as the airplane can easily out fly the range of the ; Tx. Setting the delay is done as follows: ; 1- When the Rx and wired in BitSC is powered ; up, there will be aprox 1 sec delay after which ; the motor will blip once for each 15 sec interval ; that the BitSC is set for. ; 2- After the blipping has stopped there is a 2 sec ; "window" wherein a new number of increments can be ; entered by pushing the "down" button the number of ; times equal to the number of 15 sec's desired. ; The first press of the "down" button holds the ; "window" open to gather the remaining presses. ; 3- After the desised number of intervals has been ; entered, the "up" button is pressed and the unit is ; ready for normal use. ; 4- In the event that the "up" button is pressed ; before the 2 sec window is over the unit will hang ; waiting for an additional "up" press to be ready. ; This has the effect of reducing the number of 15 ; sec intervals to just one, but ONLY for that single ; power up. Thus one can have several intervals of 15 ; sec stored for normal use, but can switch to just ; a single 15 sec interval when desired. ; The BitSC uses a reverse exponential lookup table ; for motor speed control. maclib 'P12F629.inc' device PIC12F629,intrc_osc,wdt_off,mclr_off,bod_off,pwrt_off,cpd_off,protect_off data org 32 tmp ds 1 ;general purpose counter cnt ds 1 ;same del1 ds 1 del2 ds 1 del3 ds 1 del4 ds 1 acc ds 1 ;acumulator for motor channel dty ds 1 ;duty cycle for motor channel speed ds 1 ;motor speed for table lookup delnum ds 1 mtr = gpio.5 ;output for motor PWM down = gpio.4 ;input for decrease speed up = gpio.2 ;input for increase speed inputs = 010100b ;inputs on gp4 and 2 eeprom org 0 db 1 code org 0 setb rp0 ;switch to page 1 call 03ffh ;fetch osccal nomber (FOR 1ST TIME CHIP PRGMING) mov osccal,w ;move it into osccal (FOR 1ST TIME CHIP PRGMING) ; mov osccal,#112 ;move cal# previously found at 03FF into osccal ;USE THIS METHOD AFTER 1ST TIME CHIP PROGRAMMING clrb rp0 ;switch back to page 0 jmp start table jmp pc+w retw 0,0,45,64,78,91,101,111,120,129,137,145,152,159,166,172,178,184 retw 190,195,200,205,210,215,220,225,230,235,240,245,250,255,255,255 start clr tmp clr cnt settle jmp $+1 ;wait aprox 1 sec jmp $+1 jmp $+1 jmp $+1 jmp $+1 jmp $+1 djnz tmp,settle ;for processor to settle djnz cnt,settle setb rp0 ;switch to page 1 mov trisio,#inputs ;set inputs clr option ;enable global pullups mov wpu,#010100b ;enable gp2 & gp4 pullups clrb rp0 ;back to page 0 mov cmcon,#00000111b ;free gpio.0,1,2 (set comparator to off) clr gpio clr dty clr w ;set w to 1st eeprom memory location call eread ;read from eeprom, returning in w mov delnum,w ;transfer to delay number mov cnt,w ;and also to cnt jmp strtblp ;jump around delay nxtblip call dely5 ;wait about a sec strtblp mov del2,#100 ;blip motor once for each 15 sec delay blip setb mtr ;turn motor on djnz del1,blip ;1st delay loop djnz del2,blip ;2nd delay loop clrb mtr ;turn motor off djnz cnt,nxtblip ;decrement cnt and repeat if not zero mov tmp,#10 ;setup 3rd delay element chksetd jnb up,setdel ;check if up button pressed djnz del1,chksetd ;1st loop djnz del2,chksetd ;2nd loop djnz tmp,chksetd ;3rd loop setb gpio.0 ;optional led at pin 7 can be used to ;indicate programing window is over setspd mov speed,#1 ;speed needs value other than zero getsigs clr del1 ;initialize delay values clr del2 mov del4,delnum setdel3 mov del3,#11 ;this delay variable gets delnum chksigs jnb up,incrse ;checking up button here, go if pushed jnb down,decrse ;checking down button here, go if pushed call pwm ;keep up pwm djnz del1,chksigs ;start of 15 sec timing djnz del2,chksigs djnz del3,chksigs djnz del4,setdel3 nxtchk jnb up,incrse ;button press here will leave delay loop jnb down,decrse ;same as above call pwm ;keep up pwm mov w,speed call table mov dty,w call dely30 djnz speed,nxtchk ;dec speed and loop back to check buttons jmp setspd ;timed out, start over incrse inc speed ;inc speed index csb speed,#33 ;compare & skip next if speed < 33 dec speed ;if speed = 33 then dec speed jmp getw ;jump around decrease speed decrse dec speed ;dec speed index snz ;skip next if speed not down to zero inc speed ;if it is zero then inc it getw mov w,speed ;speed goes to w for table lookup call table ;get value from table mov dty,w ;and transfer to dty call dely12 ;delay some jmp getsigs ;jump back to check buttons again pwm add acc,dty ;add duty to accumulator sc ;if add carried then clrb mtr ;skip clearing motor bit snc ;if add didn't carry then setb mtr ;skip setting motor bit nop ;add some time here nop nop nop ret dely30 mov cnt,#30 ;setup cnt for looping jmp next ;jump over next setup dely12 mov cnt,#12 ;setup cnt for looping next call pwm ;keep up pwm while looping here for djnz tmp,next ;about 3/4 sec to slow down constant djnz cnt,next ;repeating before going back to check ret setdel clr tmp ;always jnb up,$ ;wait until signal is hi again djnz cnt,$ ;debounce signal getbtn jnb down,incdel ;go if signal turns lo jnb up,finish ;go if signal turns lo jmp getbtn ;loop back for to check buttons incdel jnb down,$ ;wait till signal hi again djnz cnt,$ ;debounce signal inc tmp ;inc counter clr w ;set eeprom location call ewrite ;write tmp to eeprom memory jmp getbtn ;jump back to repeat finish mov delnum,tmp ;move counter to delay number for use snz ;skip next if not zero inc delnum ;inc it if it was zero jmp setspd ;jump back to get button presses dely10 mov tmp,#10 jmp nxtdely dely5 mov tmp,#5 nxtdely djnz del1,nxtdely djnz del2,nxtdely djnz tmp,nxtdely ret eread setb rp0 ;eeprom read for 12F629 here mov eeadr,w setb rd mov w,eedata clrb rp0 ret ewrite setb rp0 ;eeprom write for 12F629 here mov eeadr,w mov eedata,tmp setb wren mov eecon2,#55h mov eecon2,#0AAh setb wr jb wr,$ clrb rp0 ret