Re: Rotary Encoder on 20x4 LCD with pushbutton digit select and other features
if you do it more algorithmically the size can be reduced dramatically ,it becomes scalable digit wise
more functions can easily be added and the mcu can be employed to perform a real task like pid control of a power supply and not just become a display controller
ps note my lcd defines suite my setup and are different
Code:'**************************************************************** '* Name : LCD_TEST.BAS * '* Author : RICHARD * ' '* Date : 4/8/2017 * '* Version : 1.0 * '* Notes : * '* : 16f887 * '**************************************************************** #CONFIG __CONFIG _CONFIG1, _LVP_OFF & _FCMEN_OFF & _IESO_OFF & _BOR_ON & _CPD_OFF & _CP_OFF & _MCLRE_ON & _PWRTE_ON & _WDT_OFF & _INTOSCIO __CONFIG _CONFIG2, _WRT_OFF & _BOR40V #ENDCONFIG DEFINE OSC 8 'LCD defines begin here DEFINE LCD_BITS 4 'defines the number of data interface lines (4 or 8) DEFINE LCD_DREG PORTB 'defines the port where data lines are connected to DEFINE LCD_DBIT 0 'defines the position of data lines for 4-bit interface (0 or 4) DEFINE LCD_RSREG PORTB 'defines the port where RS line is connected to DEFINE LCD_RSBIT 4 'defines the pin where RS line is connected to DEFINE LCD_EREG PORTB 'defines the port where E line is connected to DEFINE LCD_EBIT 5 'defines the pin where E line is connected DEFINE LCD_COMMANDUS 1500 'defines the delay after LCDOUT statement DEFINE LCD_DATAUS 50 'delay in micro seconds 'END of LCD DEFINES Pause 500 ' LCD initialize time lcdout $FE,1 num_digits con 5 ; range 4 t0 9 tested ok note sum_total will not work for more than 5 digits sw_threshhold con 10 lp_threshhold con 100 ;long press sw_inhibit_time con 100 msd_limit con 5 ;limit value for msd note sum_total will not work for more than 5 digits and limit > 5 ;optional digit var byte[num_digits-1] d_index var byte overflow var bit underflow var bit noroll_flg var bit ;optional d_inx var byte sw_cnt var byte sw_flag var bit re var byte last_re var byte ev var byte tmp1 var byte tmp2 var byte ;optional tmp3 var byte ;optional sw_inhibit var byte total var word enc_sw var PORTC.4 enc_a var portc.5 enc_b var portc.6 clear d_index = num_digits re = porta&48 last_re = re gosub dup main: if !sw_inhibit then gosub chk_sw if sw_flag then ;service the sw if active if sw_cnt > lp_threshhold then ;long press clears settings for d_index = 0 to (num_digits-1) digit[d_index] = 0 next gosub dup else d_index = d_index - 1 ;increment set digit {index posn 6 will stop editing of settinge} if d_index > num_digits then d_index = num_digits gosub set_cursor sw_inhibit = sw_inhibit_time ; don't reactivate sw immediately [more user friendly] endif sw_cnt = 0 sw_flag = 0 endif ;poll encoder a poll rate of 5-10ms is adequate re = portc&96 if re != last_re then ;encoder has moved ev=ev<<2 ;shift old reading into position for compare ev=ev|((portc&96)>>5) ;read enc pins 4,5 mask off others then combine this reading with last reading ;lookup table is a form of digital filter to debounce encoder [no caps used on encoder at all] LOOKUP (ev&$f),[0,255, 1, 0, 1, 0, 0, 255, 255, 0, 0, 1, 0, 1, 255, 0],tmp1 ;lookup the decision matrix to determine rotation endif ;service encoder result if there is one if tmp1 && re == 0 then ; tmp1 255 is anticlockwise or 1 for clockwise [swap a/b pins if direction incorrect] if d_index != num_digits then if tmp1 = 255 then gosub dec_digit else gosub inc_digit endif endif gosub dup tmp1 = 0 endif ;service sw inhibit if necessary if sw_inhibit then sw_inhibit = sw_inhibit - 1 ; [make sw action more user friendly] pause 5 ;adjust to suite desired responsiveness or more functions in loop goto main dup: ;update lcd LCDOUT $FE, $94 tmp1=num_digits while tmp1 tmp1=tmp1-1 if tmp1 = 1 then LCDOUT ".", digit[tmp1]+$30 else LCDOUT digit[tmp1]+$30 endif wend gosub SUM_TOTALS LCDOUT $FE, $80, dec5 total set_cursor: ;update cursor if d_index == num_digits then LCDOUT $FE,$0C elseif d_index > 1 then LCDOUT $FE,$0f,$fe,$94 + (num_digits - 1) - d_index else LCDOUT $FE,$0f,$fe,$94 + num_digits - d_index endif return inc_digit: ;inc current digit d_inx = d_index gosub norollu ;optional if noroll_flg then ;optional digit[d_index] = digit[d_index] + 1 gosub chk_ovf while overflow digit[d_inx] = 0 d_inx = d_inx + 1 if d_inx >= num_digits then return gosub norollu ;optional if noroll_flg then ;optional digit[d_inx] = digit[d_inx] + 1 gosub chk_ovf endif ;optional wend endif ;optional return chk_ovf: ;check if overflow occured overflow = 0 if digit[d_inx] > 9 then overflow = 1 return chk_unf: ;check if underflow occured underflow = 0 if digit[d_inx] > 127 then underflow = 1 return dec_digit: ;decrement current digit d_inx = d_index gosub norolld ;optional if noroll_flg then ;optional digit[d_index] = digit[d_index] - 1 gosub chk_unf while underflow digit[d_inx] = 9 d_inx= d_inx + 1 if d_inx >= num_digits then return gosub norolld ;optional if noroll_flg then ;optional digit[d_inx] = digit[d_inx] - 1 gosub chk_unf endif ;optional wend endif ;optional return chk_sw: ;see if switch is active if sw_flag then return if !enc_sw then if sw_cnt < 255 then sw_cnt = sw_cnt + 1 else if sw_cnt > sw_threshhold then sw_flag = 1 endif return norolld: ; stop rollunder from 0000.00 to 9999.99 ;optional tmp3=digit[d_inx] ;optional noroll_flg=0 ;optional for tmp2=(d_inx+1) to (num_digits -1) ;optional tmp3=tmp3+digit[tmp2] ;optional next ;optional if tmp3 then noroll_flg = 1 ;optional return ;optional norollu: ; stop rollover from 9999.99 to 0000.00 and limit msd noroll_flg=0 ;optional if d_inx < (num_digits -1) then ;optional tmp3=9-digit[d_inx] ;optional for tmp2=(d_inx+1) to (num_digits -2) ;optional tmp3=tmp3+(9-digit[tmp2] ) ;optional next ;optional tmp3=tmp3+(msd_limit-digit[tmp2] ) ;optional else ;optional tmp3=msd_limit-digit[d_inx] ;optional endif ;optional if tmp3 then noroll_flg = 1 ;optional return ;optional SUM_TOTALS: ;max digit is 5 and max_msd = 5 or else result will overflow tmp1=num_digits total=0 while tmp1 tmp1=tmp1-1 total=total*10 total=total+digit[tmp1] wend return
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