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Darrel... i don't think it will be revealant to be 50% or not... it's all about pulse/miles after all.
In the good ol' time we installed 2 magnetic sensor on the drive shaft as a VSS generator. using that... no way you could have a 50% duty cycle as the magnets where about 1 inch wide.
I should take a car ride here and record the VSS signal to see how clean it is... in case some want to know.
Steve
It's not a bug, it's a random feature.
There's no problem, only learning opportunities.
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AAAAAAAAAAAHAHAHAHAHAHHA i knew that one of my OLD cruise control installation manual would be handy one day or another... here's a quote of the revealant part...
<table><tr><td></td><td>
</td><td>Originally Posted by Good ol' dusty manual
</td></tr></table>
Last edited by mister_e; - 2nd March 2007 at 02:04.
Steve
It's not a bug, it's a random feature.
There's no problem, only learning opportunities.
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It was easier than I thought, just more of the same stuff.
<table><tr><td>IdleState CON 0</td><td>
IdleState CON 1</td></tr></table>
HTH,Code:'**************************************************************** '* Name : FREQx2.bas * '* Author : Darrel Taylor * '* Date : 3/1/2007 * '* Version : 2.0 * '* Notes : Doubles the frequency of input pulses, * '* : and maintains the same DutyCycle as the Input. * '* : Range = .1hz to 500 hz (0-40% DutyCyle) * '* : Target = PIC12F629/675 * '**************************************************************** @ __config _INTRC_OSC_NOCLKOUT & _WDT_OFF & _MCLRE_OFF & _CP_OFF DEFINE NO_CLRWDT 1 Clear SpeedPin VAR GPIO.2 ; Input from speed sensor SpeedX2Pin VAR GPIO.4 ; Output to Speedometer IdleState CON 0 ; State of input when sensor ; is not on a "Slot" NotIdle CON IdleState ^ 1 LastState VAR BIT ; Last state the Input changed to LoopCount VAR byte ; Counts the loops of each pulse LoopCount1 VAR byte LoopCount2 VAR byte PulseWidth VAR byte BANK0 ; Counts the loops of output pulse PulseWidth1 VAR byte BANK0 PulseWidth2 VAR byte BANK0 LastPulseWidth VAR byte ; saved width of last pulse LastPulseWidth1 VAR byte ; so it can duplicate it LastPulseWidth2 VAR byte CycleWidth VAR byte BANK0 ; Counts the loops of output cycle CycleWidth1 VAR byte BANK0 CycleWidth2 VAR byte BANK0 OutPulseCount VAR BIT CMCON = 7 'ANSEL = 0 ; for 12F675 SpeedX2Pin = IdleState OUTPUT SpeedX2Pin Main: LoopCount = LoopCount + 1 ; 24-bit counter If LoopCount = 0 Then LoopCount1 = LoopCount1 + 1 if LoopCount1 = 0 then LoopCount2 = LoopCount2 + 1 endif endif IF SpeedPin <> LastState then ; If Input State Changed? LastState = SpeedPin if LastState = NotIdle then ; Start of Input Pulse CycleWidth = LoopCount CycleWidth1 = LoopCount1 CycleWidth2 = LoopCount2 ASM bcf STATUS,C ; CycleWidth = LoopCount / 2 rrf _CycleWidth2, F ; Output Cycle is half of Input rrf _CycleWidth1, F rrf _CycleWidth, F ENDASM LoopCount = 0 ; reset LoopCount LoopCount1 = 0 LoopCount2 = 0 else ; End of Input Pulse PulseWidth = LoopCount PulseWidth1 = LoopCount1 PulseWidth2 = LoopCount2 ASM bcf STATUS,C ; PulseWidth = PulseWidth / 2 rrf _PulseWidth2, F ; Output Pulse is half of Input rrf _PulseWidth1, F rrf _PulseWidth, F ENDASM LastPulseWidth = PulseWidth LastPulseWidth1 = PulseWidth1 LastPulseWidth2 = PulseWidth2 SpeedX2Pin = NotIdle ; start First Output Pulse OutPulseCount = 0 endif else if SpeedX2Pin = NotIdle then if PulseWidth = 0 then ; countdown output time (24bit) if PulseWidth1 = 0 then if PulseWidth2 = 0 then SpeedX2Pin = IdleState ; end of pulse, else ; wait for next transition PulseWidth2 = PulseWidth2 - 1 PulseWidth1 = 255 PulseWidth = 255 endif else PulseWidth1 = PulseWidth1 - 1 PulseWidth = 255 endif else PulseWidth = PulseWidth - 1 endif else @ NOP ; Keep the loop symmetrical @ NOP @ NOP @ NOP @ NOP endif if OutPulseCount = 0 then if CycleWidth = 0 then ; countdown to Midpoint of cycle if CycleWidth1 = 0 then if CycleWidth2 = 0 then SpeedX2Pin = NotIdle ; Start second pulse OutPulseCount = 1 PulseWidth = LastPulseWidth PulseWidth1 = LastPulseWidth1 PulseWidth2 = LastPulseWidth2 else CycleWidth2 = CycleWidth2 - 1 CycleWidth1 = 255 CycleWidth = 255 endif else CycleWidth1 = CycleWidth1 - 1 CycleWidth = 255 endif else CycleWidth = CycleWidth - 1 endif else @ NOP ; Keep the loop symmetrical @ NOP @ NOP @ NOP endif endif goto Main end
DT
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The knowledge and experience you guys have amaizes me !
Woke up this morning and checked this thread and found a suggested schematic from Steve and revised code from Darrel ! - Thanks guys.
I'll compile and burn the code to a 12F675 and send it to my mate for testing.. I'll report back on his findings in a couple of days
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I would just like to point out that in the event of your mate getting caught for speeding, Steve and Darrels contribution towards the speeding fine will be limited to the amount paid for the code and schematic
Keith
www.diyha.co.uk
www.kat5.tv
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I don't know if I could afford that Keith
I think Steve's circuit will invert the output, so I'll need to reverse the pulse in the program to be able to use that.
And you need an input circuit. I was thinking something like the circuit below might be nice. And, I'll need to make it use the GP0 input to determine what the Idle polarity is.
I smell a Version 3.
I tried something else, then realized it wouldn't work.
What do you think about this one.
Click Image to Enlarge
Click Image to Enlarge
DT
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Keith, I like where you're coming from
Darrel, that looks good. I've already pointed my mate to this forum so he can keep up to speed to see what a stirling effort you guys are doing !
Thanks guys !
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