I'm writing a routine to a tachometer. I just doesn't work! I've searched the forum, but i haven't found anything that looks like this.
Code:
'****************************************************************
'* Name : Tacho.BAS *
'* Author : Christian Lerche *
'* Notice : Copyright (c) 2008 Lerche *
'* : All Rights Reserved *
'* Date : 07-10-2008 *
'* Version : 1.0 *
'* Notes : PIC16F84A @ 10 Mhz XT *
'* : XT osc, BODEN off, WD off *
'****************************************************************
'Include------------------------------------------------------------------------
'Definitions--------------------------------------------------------------------
Define osc 10 ' Define Osc as 10 Mhz
DEFINE PULSIN_MAX 25000 ' Lowest RPM 600
'Inputs/outputs-----------------------------------------------------------------
TRISB = $80 ' All PortB Output
TRISA = $f0 ' All PortA Output
INPUT PORTA.4 ' PortA.4 Input
'Variables----------------------------------------------------------------------
B0 VAR BYTE ' Define B0 as byte
W1 var WORD ' Define W1 as word
'Main program-------------------------------------------------------------------
loop:
IF PORTA.4 THEN ' Wait until start of low pulse
GOTO MAIN1
ELSE
GOTO loop
ENDIF
MAIN1:
PULSIN PORTA.4,0,W1 ' Measure pulse-width in 4µS resolution
GOTO MAIN
MAIN:
W1 = W1 * 4 ' Convert µS to mS
W1 = (60000 / W1) ' Revs in 60 mS
W1 = W1 * 1000 ' Revs in 60 sec
GOSUB display ' Go to display sobroutine
GoTo LOOP ' Do forever
'Display subroutine-------------------------------------------------------------
display: B0 = W1 / 1000 ' Find number of thousands
W1 = W1 // 1000 ' Remove thousands from W1
Gosub bin2seg ' Convert number to segments
PortB = B0 ' Send segments to LED
PortA = $17 ' Turn on fourth digit
Pause 1 ' Leave it on 1 ms
PortA = $1F ' Turn off digit to prevent ghosting
B0 = W1 / 100 ' Find number of hundreds
W1 = W1 // 100 ' Remove hundreds from W1
Gosub bin2seg ' Convert number to segments
PortB = B0 ' Send segments to LED
PortA = $1B ' Turn on third digit
Pause 1 ' Leave it on 1 ms
PortA = $1F ' Turn off digit to prevent ghosting
B0 = W1 / 10 ' Find number of tens
W1 = W1 // 10 ' Remove tens from W1
Gosub bin2seg ' Convert number to segments
PortB = B0 ' Send segments to LED
PortA = $1D ' Turn on second digit
Pause 1 ' Leave it on 1 ms
PortA = $1F ' Turn off digit to prevent ghosting
B0 = W1 ' Get number of ones
Gosub bin2seg ' Convert number to segments
PortB = B0 ' Send segments to LED
PortA = $1E ' Turn on first digit
Pause 1 ' Leave it on 1 ms
PortA = $1F ' Turn off digit to prevent ghosting
Return ' Return to main
' Routine copied from ledart.
'Lookup table-------------------------------------------------------------------
bin2seg:
Lookup B0,[$40,$79,$24,$30,$19,$12,$02,$78,$00,$18],B0
Return
Originally Posted by ThaSanta
I'm writing a routine to a tachometer. I just doesn't work! I've searched the forum, but i haven't found anything that looks like this.
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