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  1. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    Mar 9 exp no 4 update first off is the code for the signals 508-1 uC in it line 47 has the w-register loaded with a number. this number is meant to be the time between the LE's in u-sec (us) as a test of the code w-reg was filled , in order , with 50 , 100 and 200. next are posted screen...
  2. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    mar 8 .............. more ideas about exp. no. 4 it occurred to me that as soon as the A0 LE was detected by 508-2 it could issue a LE for its A0 pin and start a copy-pulse. then , next , when the 508-1 A1 LE is detected the 508-2 would issue a TE on its A0 pin. and i think the 508-2...
  3. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    mar 7 you will soon see how the code for both the 508's contains a move not seen before. oh, those of you who are plowing thru the Gooligum baseline lessons will have. in lesson 5 ex. 1 . where , in a loop , TMR0 is being continually compared to the number 250. this lesson 5 ex. 1 tests...
  4. bob weir

    review of Sport Devices CDI digital ignition 16F84A code for a 2 cycle gas engine

    mar 7 the last post on mar 3 needs some editing. on the topic of using the MCLR pin once it is configured _OFF . this pin is input only. and we can still have 4-74164 circuits. to do this the FW ( flywheel ) pulse into pin B0 will have to be re-routed to pin 4. and then pin B0 will be...
  5. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    mar 7 update the sketch is a 'picture' of what exp. no. 4 is attempting to do. one uC , 508-1 , acts as a signal generator. and the 2'd uC , 508-2 , takes these 2 pulses as inputs and measures the time between their LE's. and saves this 'time' in some variable , call it delta_t then...
  6. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    mar 5 update while working the next exp , no. 4 , something came up. a lack of knowledge. thus uncertainty with how to proceed. lets go back to the code for exp 3. on p.1 line 41 bit 3 = 1 ... this is done in order to setup TMR0 to count in single-uS steps. and on looking at line 13 we...
  7. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    mar 3 update a change is being made to the 16F506 signals circuit. the old one uses 8 of its pins for leds. the leds show the hex value of the TMR0 register. this then is the spacing between the -70 and -10 flywheel pulses in units of 32us. for long it has bothered me that these leds...
  8. bob weir

    review of Sport Devices CDI digital ignition 16F84A code for a 2 cycle gas engine

    an alternative circuit is to use all 8 PORTB pins each with a led. this could be done. the penalty is only seeing one hex byte variable at a time. and , worst of all, it means upwards of an extra 100ma of current flowing thru the uC. the 74164 circuits are powered separately . and all the...
  9. bob weir

    review of Sport Devices CDI digital ignition 16F84A code for a 2 cycle gas engine

    feb 24 ..... update on review of the S/D 84A ignition system and its asm code this screen shot off the scope is of some 509 code. the code is 'signal' code. until now the 16F506 has been a source of test signals. only its operation has been erratic and unreliable of late. so its being set...
  10. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    feb 22 .................. wait ............ there's more. regards the feb 21 exp 3 post ... the scope reveals the 32u A0/A1 pulses arent exactly 32u either. more like 39u this is more of a s/w matter than one due to using the internal RC OSC. that dly32u subroutine is , by its very code...
  11. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    feb 22 more images of the feb 21 post of exp 3 . in color and with the cursors. on reading the BX-AX numbers we learn the scope facts. they show that the trip point is closer to 131u than 128u . i'm looking at the code lines 48 to 54 . and asking what is going on here. more than meets the...
  12. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    feb 22 these scope images will show you the signal traces in the colors referred to in the post yeserday the 21'st see p. 10 post feb 22 for these same color images with the cursors. the cursor will show you that these results were not quite so rosy as first believed
  13. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    feb 21 line 59 and 60 use the command SUBWF then test STATUS bit C. this is how you decide if the pulse width on the A5 pin is more or less than 128u. the Gooligum baseline lesson 5 covers both of these features and with a nice table on p. 5 another notable feature of this code appears on...
  14. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    feb 21 results of exp 3 off the list of 11 posted on feb 2. good news. it worked very well. a few changes were made vs. what was planned. the dividing line is 128u not 100u. and instead of leds to indicate which field 1-127 or 128-255 the incoming pulse is in a pulse out of A0 or A1 was...
  15. bob weir

    review of Sport Devices CDI digital ignition 16F84A code for a 2 cycle gas engine

    update feb 20 this post is to alert you to the next test of the S/D asm code. on feb 8 was posted the S/D *.asm on 4 pages. on line 138 is a comment about the first pulse not being processed. this adds uncertainty to the code issuing a fire pulse out of pin A2 with 2 B0 input pulses...
  16. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    feb 20 update summary : some coding mistakes are offered as examples to watch out for since last week i've been chasing my tail. stuck in a loop where the code doesnt work. several programs were not running right. so after some thought the header section was re-done to match the template...
  17. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    feb 12 the 2'd exp of the series of 11 is finished . and is now being posted. going into it i thot it would be a piece of cake. instead it kept me busy for many hours. and revealed how easily small details can take you back to class. the lessons learned and the sense of being on the learning...
  18. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    feb 10 update this report is to highlight a problem i'm having keeping the many asm files straight. and discovering more thought and organization is needed. what happens is i get some 506 and 509 code to play together. then think of something to change. only i'm not careful with documenting...
  19. bob weir

    review of Sport Devices CDI digital ignition 16F84A code for a 2 cycle gas engine

    feb 8 posted are 4 *.jpg scans of the SD 84.asm . the pages all have line numbers. they can easily be printed out thus you will be able to follow along when code is referenced by them. for instance while this asm file was BUILT earlier this eve it did build but came with 3 warnings. all 3...
  20. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    feb 6 often enough the path to knowledge is by making mistakes. trying what you think is right and then working the results you didnt get for their hidden reasons. on sunday i was trying to change the 12F508 asm file into one that would run on a 12F509. ( same processor with twice the memory )...
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