Open Issues ToDo
Trigger Question
12-1 Wheel single cylinder VR primary trigger
Signal being generated by parallel port to op-amp
Signal is zero to -3 to +4 to zero
Total pulse is 1/20 of the pulse to pulse period
single pulse spacing is .794 msec
RPM=[1/(.000794*12)]*60 or 6297rpm
- Megatune displays 1570 which is almost exactly off by a factor of four
- another_trigger_tooth with 12-1 crankwheel, use 24 / cylcount
- rpmk[0] and rpmk[1] (upper and lower bytes, respectively): use 12000 / cylcount
Dump from V3.3
primary_trigger=01 #
secondary_trigger=02 #02 is disabled says Megatune and one configuration example while another configuration example says it is disabled if 0FF?????
tooth_wheel=0B # wiki says actual number of teeth 12 -1 or 11 decimal 0B hex
trigger_tooth=01 #left at one for now as "timing" not yet important
another_trigger_tooth=06 # with 12-1, 06 means 2 events per crankrot, that is 4 events per camrot (4cyl)
crank_minper=9C #entered 2000 for now wiki says this should be 60sec / max RPM / number of engine events * 2 which would be 60/8000/1*2 or 15,000 usecs this number was not accepted by Megatune
tooth_wheel_twidth1=0A #wiki says dec=255/(2*imag teeth) or 255/(2*12)=10.xxx phase 240 for 12-1 and twidth1=phase/(imag teeth * 2) or 240/(12*2) or 10 dec/ 0A hex
tooth_wheel_twidth2=14 #wiki says (missing teeth +1)* dec or (1+1)*10 =20 dec or 14 hex
I beleive I have followed the wiki examples and my VR pulse input looks ok. Can anyone provide some guidance.
History
Does the V3.3 firmware calculate base injector pulse width using VE and Required Fuel only or does it factor in A/F values from the A/F table? Put differently, is the A/F table only for autotune or is it also used for open loop injector pulse width calculations? Is there a detailed explanation of exactly how the injector pulse width is calculated apart from trying to decipher the C code?
A: The lambda target table is always in use in the calcs, i dont know where to find the description though //Emil
Please advise on what is connected to the flying green jacketed wire protruding from the front cover with white and green wires.
A: Exhaust Temp sensor I will look to Wiki fof hookup info, page GenBoard/Manual/ExhaustGasTemp, just wire the sensor in and do the calibration described on that page
Projects Underway
MembersPage/BillHart/WinMobileLogger Win Mobile platform to Fat32 memory card logger. Looking for SIPR examples, if any, to ease the adding V3.3 query to Win Mobile code.
I would like to better understand the inside of what I have worked with for so many years from the "outside". See http://www.lolachampcar.com for more info.
Do you have a particular project engine in mind ? Yes, sub-set of V3.3 for highly targeted one to four cylinder 4-stroke fuel and ignition.
We usually call "reverse an existing ignition advance curve" as "alien" logging. Searching for alien on SiteIndex, I found OnlineCourse/AlienIgnitionLogging. Secondary_trigger can still (in recent firmwares) be configured for alien measurements (except for 5cyl), but the alien variables seem to have been ripped from comm.c. Even if they show up on LCD, only useful if they are sent to the PC (like MegaTune) for analysis. Fortunately not difficult to get comm.c send the variables related to alien measurements.
I have read a bit about the status of logging. There is discussion of building hardware to support logging. There are also those who feel PDAs are a better path. I would like to weigh in on the PDA side as there is no value add to recreating the (logger hardware) wheel. A small portion of the hardware data logger work could be devoted to PDA code to generate a log storage device. FAT, touch interface, serial, memory card slot and services are already done. Can someone advise on the current status of group thinking? Is someone working on PDA? The only link I found was a dead end.
I recommend to comment (continue discussion) on the relevant page, not split even more. In short:
- PDA is a good path for display. There is a HW and a SW aspect of GraphicalDisplay.
- Many would like to have a custom display designed for cost and other reasons (see GraphicalDisplay), but getting 100 PDA from the right source could be a good option as well.
- In any case, the display code should be portable (will likely require ARM processor and 256..16000 kbyte RAM depending on functions and compile options), and any code used in display will be useful for an OtherTuningSoftware as well. Which is - surprise - also a bit stalled.
- for just logging, MMC/SD flash is the best. It's a shame the firmware support is delayed so long: read-only FAT, and writing serialized data to MMC/SD shouldn't be that hard (SPI hardware is there since the beginning).
I am working with a 12-1 wheel and wanted to clarify a few points.
- primary_trigger=01 (for toothed wheel, simple enough)
- tooth_wheel=0B (12 minus one is 11 dec which is 0B Hex)
- tooth_wheel_twidth1=0A # decimal 10, so 720 degrees equals 240
- reset_engphase_after=F0 # decimal 240
- tooth_wheel_twidth1 needs to be the phase difference between two incoming pulses (== the width of the tooth plus adjacent gap). Beware that it's not in degrees! Unit is determined by config.reset_engphase_after (=>720 degrees), which is usually 240 or 216 depending the number of teeth on the wheel (60/24/12 or 36). GenBoard/Manual/InputTriggerCamSync should tell more.
- trigger_tooth=00 is the pulse (== max height middle for a normally conected VR) after the missing tooth. 01 is one tooth later and so on. trigger_tooth + ign_tdcdelay together describe the TDC event for the cyl that is in the last slot of h[2]. Check examples from MembersPage, easier to see from them. As you say, these are the "fiddle factor", since the tooth location usually does not fall directly on TDC.