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  1. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    april 3 here are scans of the 2 pages of parts for the 2012 CDI design. they were scanned in color so you could tell my red ink marks from the document p. 2 was printed out in b/w on my hp 3636 inkjet prt and is totally readable an error to report. on reviewing the parts list and comparing...
  2. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    april 1 here are images of the CDI pc boards. circuit board s/w is something i am yet to learn. and want to. consider this a request for assistance from one of you viewers of this forum who has a little expertise. even just a partial start would be a big help. and, if you could, to be...
  3. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    april 1 this is the circuit diagram of the 2012 design of the CDI circuit board. the original is a 354k *.png image. but the system flags an error msg about it being too large when i try to upload it to here. so it was printed , then scanned and saved as a *.jpg file. and its print here this...
  4. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    Mar 31 lets shift gears and look at the electronics side of this ignition project. work with the CDI circuit is underway here again. it really is one complex piece of circuitry. and exposes us all to another world to explore and discover. first is the circuit diagram in *.pdf format this is...
  5. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    Mar 25 and the code. for a 12F508 uC this method saves the TMR0 measurement of the time between the -70 to -10 LE's. and once saved it can be accessed & worked with by other subroutines in the program this concludes the material for exp. no. 4
  6. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    Mar 25 2'd way of catch the LE's of two incoming pulses , and then output a new pulse with width = the time between the LE's. the final CDI ignition code does this every revolution of the flywheel. i.e. measure the time between the LE of the -70 deg flywheel pulse and the following -10 deg...
  7. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    Mar 24 508 code for post above tomorrow the other code method will be posted. it will use the 508's TMR0 to measure the time between the LE's. ( -70 to -10 ) save this timer value as a variable. ( some multiple of 32us ) then after the 2'd pulse is in ( the -10 one ) the output pulse will...
  8. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    Mar 24 this post is meant to complete exp. no. 4 2 pulses enter a 508 and it then outputs a pulse with width = the time between their LE's two ways to do this will be shown. the first begins the output pulse as soon as the -70 LE is detected. then this pulse continues until the LE of the -10...
  9. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    Mar 18 another example of the scope showing false circuit test results in this case it shows nothing. repeat 'send' .. nothing . this went on for 5 times and then , viola', a Ch 4 pulse. what makes this type of result so awful is having an immediate reaction to not seeing the expected Ch 4...
  10. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    Mar 18 besides finally getting a good scope result something else arose worth mentioning. it amounts to the timing accuracy of one uC vs. the other. when the case is ours of having one uC send pulses to a 2'd uC it dawned on me that the 506 test code is using a 32u s/w subroutine to space its...
  11. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    mar 18 finally , after clearing the scope screen and pushing 'send' a 2'd or 3'd time i finally get what i expect. yes , it looks right , but is it ? verification comes of using the scope's cursor to measure all pulse widths and the spacing between them. they're not exact but i've learned not...
  12. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    mar 18 next are 4 screens of the scope showing a crazy group of pulses on the 1'st push of the 'send' button after the battery is connected and the screen cleared for the next 'single' event [/ATTACH] ... this 'send' button is one added to the 506 PORTC pin no. 3 . it was added so as to...
  13. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    mar 18 this post is to show you some (?) mis-behavior of my 1054 rigol scope. 3 of its 4 probes are connected to a 506 output pulse pins ( -70 and -10 ) (Ch 2 & 3) and to a 508 that accepts these pulses and outputs a 'fire' pulse for the CDI circuit. ( Ch 4) what i want to convey is how the...
  14. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    mar 16 the 4 pages of code posted on mar 14 are for the 16F506 uC. i've been favoring its ADC module and its 12 i/o pins. however using these features comes at a cost. briefly , besides the ADC are comparator functions . both of these modules use analog voltage level signals. and by...
  15. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    mar 15 the 1'st color scope screen shot that has BX-AX = 2620 is redone here at a different H-scale. and code line no's added. they show you what code executes for pulse creation and spacing. and added is some math to help clarify the adjustment for the width of the -70 pulse the adjustment...
  16. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    mar 15 here's the ckt diagram for the post yesterday. it shows the 16F506 uC , the 74164 and 8 leds a switch is shown on pin 4 , the /Mclr . for every push the 70,10,70 set of pulses emerge. note too the 74164:9 pin is active low. thus a 1-0-1 pulse is needed to clear the led display. lines...
  17. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    update Mar 14 the 2 scope screen shots showing the measurements between pulse edges. note how the 1'st one measures from LE to LE. this is critical. as the ignition code polls its pins for the LE of each of these -70 and-10 input pulses the 2'd image shows the measure from the -10 TE to...
  18. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    update mar 14 the blue pot is dialed in to an ADRES value of 0x50 ( 80 decimal ). which you can make out with the 8 leds , 2 of which are lit. ... b'01010000' power is via that 9V battery and the small bd.bd on the left with a 5V-regulator. it supplies juice to both the 6"x3" bd-bd with...
  19. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    update Mar 14 the 16F506 uC has been re-coded so that the 74164 displays a hex no. on its 8 leds. the 506's ADC and the external pot make signal spacing adjustment between the -70 and -10 output pulses just too easy to not have. the alternative is having to re-code a 508 or 509 every time a...
  20. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    mar 9 exp no 4 in all 3 cases the width exceeds the w-reg value. and by the same amount. isnt that interesting. it has me wanting to do a instruction-cycle timing study and learn how this 9uS happens in each case. feel free to jump in with your own timing analysis. so , naturally, some of...
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