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  1. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    Notice - for comments or questions please e-mail me. instead of posting a reply here.; by keeping postings to a minimum this project will be more readable and easier to follow along. relevant messages from viewers will be mentioned here. with preference to those doing an identical or...
  2. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    today a small study. of the coil inside the flywheel. to look at the signals it provides us for the timing of the spark. first is a sketch of the circuit and how the scope is connected. and last is the scope image. taken as the engine spun via the starter motor at about 500 RPM playing...
  3. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    hey guys , the CDI design you've seen here all along is being set aside. its been giving me fits. and needs problematic re-work to interface to. so another , simpler circuit, was searched for. and its one we're already near familiar with ( see posting june 21 '15). and now its at the...
  4. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    july 4 ... nothing yet as a follow-up to the posting last friday. still chewing on that problem ... some information is found in the 'CMOS Cookbook' and on a u-tube video about 2-diode OR gates. and it has me hopeful. instead today i thought to try and use the CDI ckt. bd. with the 2-Q...
  5. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    here's a preview of what's coming next. the latest problem to solve. what we're trying to do is get both the flywheel -10 deg pulse and the uC timing pulse to the CDI ckt bd. we want either one to trigger a 'fire' signal and cause a spark. if you look at the 2012 CDI ckt cd design in the...
  6. bob weir

    Digital programmable CDI ignition for 2-stroke engines

  7. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    more electronics matters ... the 2'd Q of the 2-Q ADC circuit is added and scoped . here you can see the CH 4 output pulse signal. it doesnt appear to dip below 0V. and it has lots steeper pulse-like edges this pulse has to connect to the U2 chip on the CDI circuit board. U2 is a CMOS...
  8. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    this sketch is the circuit the above scope signals apply to note along the scope left edge those bullets with the 1 , 2 , 3 numbers inside them. the first one , with the 1 shows us where the 0 Volt level is for that signal. this is most handy when using the DC-offset feature of the fct. gen...
  9. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    you've been reading of a so-called '2-Q' converter circuit. its sort of an ADC . it takes the analog sine waves from the flywheel coil and turns them into rough digital pulses. this post is to take a closer look at that circuit. only to start with we are studying just one of the 2 Q's...
  10. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    on the post yesterday the 'f' gate of U2 shows a small circle on its pin 6 output. the 'c' gate pin 8 for the same chip has its circle left off. U2 is a CD40106 hex inverter w/ schmitt inputs the latter feature , the schmitt input , is useful here as we will be giving it the flywheel...
  11. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    ex experiment to test CDI ckt bd to spark with a pulse input . this is a simple test circuit way to verify an external signal can fire a spark. the cdi ckt bd was powered with a 9V battery is all next will be a simulated flywheel sine signal to the 2-Q converter circuit . it will test that...
  12. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    its time to shift gears and look at the electronics side of this project. the code is ready enough to test with the engine and CDI circuit. a note - the link to sci-experiments.com posted on p. 2 no longer works. the author, dr tony alfrey, passed away last summer. we all owe him our...
  13. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    http://www.ebay.com/itm/222123576961?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT this link will take you to the stator coil set for my xt225 'cycle. the critical coil is on the left side , looking different from all the others. the other coils are for the 12V to charge the battery...
  14. bob weir

    Fuse bits?

    M- if you follow this link and find a 3-18-16 posting you will see a code example. the image has 47 lines of assembly code for the 12F508 uC. and line 3 shows how its 4 fuse-bits are configured...
  15. bob weir

    Digital programmable CDI ignition for 2-stroke engines

  16. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    April 28 update ... code editing & testing for both the '506 and '508 uC's continues. and this is a good time to introduce a new chip to the testing mix. the 74164 8-bit shift register. its purpose is to receive a byte size file value from a uC and display it in binary on the 8 leds connected...
  17. bob weir

    does debug header AC162061 for 16F690 allow input pulses during debug tests ?

    a pile of documents has been looked thru for the answer to this question. what is wanted to do during debug of a 690 circuit using my pickit-3 is measure the time between 2 incoming pulses with timer0. then see what the value is. also does this debug operation allow pulses to be...
  18. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    this next image shows the very first pair of pulses from the 506 to the 508. the scope was placed in 'single' mode and triggered on CH 2 , the -10 deg pulse. 'single' lets you catch the startup action of the 508 uC after its powered. what is puzzling is the 506 is already running when the...
  19. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    testing of the 16F506 uC and the 12F508 uC together has begun. here are 2 scope images from that testing effort. making sense of them is more challenge. as the images show the story of what the code is actually doing. instead of what i was expecting to see. the jury is still out on them...
  20. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    and now the assembly listing source code loaded into the 506 chip. running and testing the code led to these results : i got 32.0 uS delay per unit of w for w = 50 , 100 and 150 using the MPASM stopwatch. and on the scope was measured 1640 , 3250 and 4800 uS for the same 50 ...
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