MembersPage/BillHart (2006-01-18 01:03:51)

Open Issues ToDo

Summary of problem: Megatune reads RPM and MAP correctly but battery voltage is zero. Megatune will write configuration values but only after accepting the low voltage write anyway error warning. Configuration values varified using terminal, however, config can not be written in terminal (probably blocked by low voltage error. A/D must be functional as MAP is correct.

Further... put varriable supply into TPS with TPSL=0 and TPSH=ff zero volts is 0% throttle while 4.3V is 100%. Two A/D channels are working while a third attached to a voltage divider is not.

I was working with correctly scaling RPM late yesterday. Returned this morning and assembled V3.3 does not communicate well. Under Megatune the voltage is zero while correctly reading the RPM. I can dump tables in terminal but can not reflash firmware. The unit has not been opened (for that matter, it was not even moved on the bench) and thus I do not suspect we did anything to the hardware. Has anyone seen this problem?

More Information: I can not update the configuration via terminal. However, I can update values using Megatune (like RPMK(0) and RPMK(1)) and they are reflected in a terminal dump of the configuration registers. Megatune gives a voltage too low to flash, flash anyway message. I let it rewrite anyway and the write was successful.

A: Have you changed vbatt calibration? I dont remember exactly the name but you'll find it in the menus. If you have any more config related problems, please upload whole mcd and mct output, or msq file from megatune (dont forget to also write megatune version) //Emil

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

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) OK so is another_trigger_tooth=18 or 24 dec acceptable for a one cylinder 4-stroke?????

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:


I am working with a 12-1 wheel and wanted to clarify a few points.