Sometimes a bit more measurements are needed than usual.
The worst is the low-toothcount VR.
- With the 135 tooth audi it's only sectrig that's problematic (and we have very good recipe that works on factory systems and most tweakes systems as well).
- with subaru both the primary and secondary VR are the problematic low-toothcount VR: like MembersPage/SkassaSubaruNewtrigger
- this page was made after the shocking revelation of the extremely long (and therefore suspicious) MembersPage/SkassaSubaruNewtrigger where 30 deg gap > 90 deg !
Without finding out what is happening, there is little hope.
The following measurement is recommended, simultaneously
- soundcard record the input VR (resistor amplitude divided by 10 to 100 should be fine)
- soundcards sometimes invert the signal (either both channels or none). This is no big problem, for VR polarity, we have other measurements anyway.
- optional: scope record the output of the LM1815 (both channels)
- Manmde40 triggerlog (or with new nightly VT Tools/Triggerlog, save ) with 1.1.78 so we see the sectrig pulses too
- note that first sectrig + CRC was added (to firmware + VT). In firmwares since 2010-06-14 the frame format is prepared for future extensions (like ignition, injection and other event timestamps). So newer VT is needed for these firmwares (a good idea anyway)
Than start cranking. We'll syncronise the data of the different captures if necessary. Take at least 8 seconds. (or 5+5 seconds)
Triggerlog scope function
- worked well using vemstune-c.exe (from [ http://www.vems.hu/files/pacsa/ Vemstune zip ] dropped on 2010-06-11 nightly. (any newer nightly should work without such patch).
- it can conveniently capture mde40 log from Tools/Record-Analyze Triggerlog
- the scope version has realtime update
- much less keystrokes needed after any HW-change (sometimes just adjusting a potentiometer variable resistor) than earlier.
- pause, scroll a bit on canvas, and UP and DOWN arrow keys zoom in/out. LEFT-RIGHT moves.
- VT should be able to export in wav or flac, and spawn audacity with the data. It's not a good idea to reimplement the audacity GUI functions. Audacity uses the same wx library as VemsTune, so can be easily installed on same computer and run when needed.
Example file for testers.
vemstune can also analyze from file (or directly from v3)
For testers (verification purposes):
- hexdump -C, highlighting 7e frames, let's see in octave:
- s=[0x1197, 0x12be, 0x13df,0x1d8c,0x27c8,0x28e8,0x3340,0x3a83,0x3ba4,0x3ccb,0x466d,0x50a2 ];
- plot(s, "*")
- The 3-1-2-1-3... pattern is very visible.