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  1. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    the following 3 documents are a proof-of-code-idea for using a 2'd uC as a source of signals to test the ignition code with. first is the code. one page. to get it all to fit on a single page all the line spacings had to ..................... be removed then are 2 scope images. they show...
  2. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    mar 17 progress report . a square wave with a period the width of the time for 62 deg of rotation is being used as a test signal. it is believed this is ok to do. and is being applied to both input pins simultaneously. the test signal is from the TTL port of a DDS signal generator. and on p...
  3. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    progress report mar 9 . the code is ready for testing. and was loaded into a 12F508. a no-scope approach is being worked. and once the fire-signal-out looks good the scope will be attached. as only with the scope can the actual delays following the -71 signal be verified. experimenting with a...
  4. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    here is the data table for the upcoming -71/-9 ver. of CDI code note that the 2 columns 'no. 32u' & 'no. of 25u' are the literal values that will appear in the code as-is the '32u' no's are = arc_62 value that is saved then run thru the range-test section of code...
  5. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    the size of coded RPM ranges are shown in red rectangles. and a horizontal line to the left shows what the BTDC timing angle is for that range of RPMs. for a first try only 9 ranges are coded : no. 0 to no. 8 ex. for range-test no. 3 , 2600 to 3000 RPM ... the timing is -16 deg next...
  6. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    feb 25 2016 while working the calculations for the literals in the code some new ideas came to mind. the images show where they derive from the scope image is of the flywheel timing signals in their raw sine form. these 2 signals come from the sensor coil that gets swept by the magnet on the...
  7. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    this is the first draft for ver. 1 of the new cdi code that uses the -71 and -9 signals. and a psa of 64 uS , not 128 uS as with the earlier 3 versions of code a reminder for those of you who are new to this code ... this -71 / -9 version is using TMR0 to measure the time of rotation of an...
  8. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    the dashed or slanted lines in the horiz. rectangles mean the exact time is a variable B and G are identical except for G showing the TMR0 is running all the time. and only during the B time frame do we care what the TMR0 is doing if you set bit 5 of OPTION to '1' the TMR0 wont...
  9. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    guys - a sketch is being worked on. and should be ready to post in a day or two. it will show the code action in terms of the 360 degrees of flywheel rotation timeline. it is meant to aid understanding the big picture of what the program does. and where a note of warning ... since the...
  10. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    pseudo code for ver 1 of -71/-9 cdi code ............................. feb 8 2016 variables : c1 , c2 ; both used by subroutine dly25u ................... e1 , e2 ; both used by sub' dly25 ..................... t_dly ; a value...
  11. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    humble apologies for the error in the posting yesterday. its on the sketch-with-notes--table page. the note along the right side ... "the code has from -71 to -31... " the code ( for the RPM range-tests ) cant run at -71 as that is when the delay-to-fire code has to run. the range test code...
  12. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    no way was found to make the ver 3 code work to my satisfaction. the problem was out-of-range low RPM values . they had the same appearance as did the in-range values. the code had no way to tell if the TMR0 value was an overflow value or not. if this baseline uC had a flag to tell you...
  13. bob weir

    Digital programmable CDI ignition for 2-stroke engines

  14. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    for the sake of the person new to this CDI ignition code forum and a reminder to everyone else here is a summary of the path we have taken thus far : version 1 of the code produced one fire pulse a calculated delay after the 2'd one of a pair of -71 deg signals off the flywheel version 2...
  15. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    by the jan 13 posting table of data you can read that the code produces 'fire' pulses for input signals that are out of range in terms of the RPMs. ideally the engine spark plug fires only when the rev's are in the RPM range the code was written...
  16. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    this set of data shows both the delta-t delay for in-range RPMs and out-of-range RPMs too. a reminder and by the table of data above you know the RPM range this code as is written now for is 32 - 81 Hz or 1920-4860 RPM . the lower end is limited by the prescalar choice of 128. and...
  17. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    ; note - jan 6, 2016 this is the ver. of code that led to the rigol screen shot posted yesterday ; it was copied from the .mcp project screen with the .asm listing shown. the copy-paste ; process from MPLAB IDE 8.70 s/w to this sites editor caused the layout to become messy. ; when you go...
  18. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    this rigol screen image shows the fire pulse after each -71 pulse with equal delays. this is the goal of the ignition assembly code program. via previous posts you recall the code was firstly delivering a fire pulse after every other -71 pulse. and in later code , delivering a fire...
  19. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    in the upcoming edited ignition code the command "movwf " is used 2 times in a row with different destination registers. this command is moving the contents of the w-register to some file. left unsaid in the instructions section of the 12F508 manual is what happens to the contents of the...
  20. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    lets look at the 2 screen time delays and try to understand how they were created. the basis for this idea is the time delays are both code - driven. so with the delays lets work back wards and get the multiples of the line 40 dly25 and line 160 dly25u code . and play with them for a...
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