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  1. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    another idea , for perspective , is that with a ( mid-range ) uC that has 2 timers in it , not just one like these 'baseline' uC's have , each timer could begin counting alternately after every -71 input pulse. our code , again ,will fire with the same time delay at least two times in a...
  2. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    and here is the code. before writing this post one idea to fix this mess was to use the MPLAB simulator and step thru some of the code and watch what is going on with some of the registers. and in writing today's post above with the screen image another idea came to me. where there is an...
  3. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    on the nov 29 post some of you have noticed the above rigol screen image has only one fire pulse , blue , not two. there is suppose to be a blue fire pulse after every -71 deg input pulse. oh , every other pulse , as shown ,could work. some of the time. in a 4-cycle engine this post is...
  4. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    here are color scans of the 2 pages of the current version of assembly code for this CDI ignition project as it is now the only way i know to print the *.asm code with line numbers is via MPLAB IDE with the project open. then take those two print sheets and scan them into a *.jpg file. the...
  5. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    here is a table of data from the bench test a few days ago,. note that the signal generator is a digital one. so the HZ column is integer, and increases in single HZ units. this made it nice to evaluate and verify the size of the RPM ranges in an integer fashion, to the nearest...
  6. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    this sketch shows the pulse generator and rigol scope connections of the uC 12F508 uC circuit that was tested with the latest version of code. pul_2.asm
  7. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    the fire pulse can be seen just to the right an 1/8" or less from the 2'd yellow pulse. it doenst look like a pulse tho, the pulse is too narrow to even show up as a line. all we can see for sure is its very top. , in blue. a blue dot this scaling was referred to in the last posting. when...
  8. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    the code was updated , that is to say its known errors were fixed. it was tested with the MPLAB IDE simulator stopwatch and all the numbers looked good. to affirm the code changes resulted in timing delays that were all in their expected range. then a uC 508 was programmed...
  9. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    this *.jpg table shows the literals in column 7 that appear in the code lines 41-85 for the range tests, posted oct 8 here's the math for the t0 line 41 code , col 7 of this table : .0300/128u = 234 the .0300 comes from : inverse ( 2000 rpm / 60 sec/min ) here's...
  10. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    hey guys , the work on this project has slowed. in fact nothing's been done since the last post. same as for you , there are a lot of other things to do that are grabbing for my time. including camping trips to the mtn's here in colorado. a major storm is upon the land this week with snow in...
  11. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    there are a few more tests to perform before connecting the uC to the cycle. first is to simulate the nmbr value returned by the TMR0 code and verify the range test correctly locates them all. the results of this test will be posted second is to use the simulator with the watch window and...
  12. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    this sheet shows test results of using the MPLAB stopwatch tool. all 12 delay paths were tested. the time delay as measured by the stopwatch was compared with what was expected. this expected value is simply the decimal number in the movlw lines multiplied by 25u. and the 200 u fire pulse...
  13. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    here is the cdi ignition code from the other day with a few changes. one reason no fire pulse was output was due to the lack of 'call dly25u' at line 138. also there was some mis-use of a goto when a call was needed. there's been some re-labeling of the delay code , lines 90 - 123 to...
  14. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    here is a screen foto of the PICkit-3 s/w screen after a successful transfer of the cdi ignition hex file to a 12F508 chip the cursor points to '800' which is the last memory location used. its address is 078 hex. which is 7x16 + 8 = 120 decimal at this point this is all the program space...
  15. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    the different flow-diagram blocks of code were put into one program. and it built. then was tested with a signal generator and the rigol 1054 scope. to see if the -71 deg simulated signal from the flywheel would lead to a fire signal. nothing. no fire signal pulses were observed. oh , there...
  16. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    another misprint that would have been caught by someone reading more carefully. its the 4'th from the bottom paragraph of the most recent post. on sunday sept 27. the line begins "by now from working ... " . and the misprint is " ... declare an output pin ..." . it...
  17. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    on review the sept 15 post with that table of 8 columns of numbers ... there is an error in the bottom 2 lines ... the paragraph that begins " my approach with the code ... " it refers to column 8 when it should say column 7. the 7'th column is the delay to wait for that particular range of...
  18. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    we're just about done with the code . the next post will address the signal to fire the spark plug. this preview is to let you know the energy involved. from the CDI circuit board designer, dr tony a. , it was learned that 30 mJ is enough, so for now that value is what i'm working with...
  19. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    sept 23 2015 delay code for 19usec delay per w-value w delay , usec 10 195 20 385 50 955 100 1905...
  20. bob weir

    Digital programmable CDI ignition for 2-stroke engines

    tn is the test range number. 0 to 11 , for the rpms from 2000 to 5100. and whats new now is the 7th column. it is the wait time for that test until it is time to fire the plug. the last column is the number of 20usec units of time in 8-bit decimal equivalent numbers. the reader is left...
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