can we use logic level fets instead of igbts for ignition?

[orlovsn]

after wiring problems we got smoked a couple of injectors fets and a couple of ignition igbts, igbt driver seems to be dead also
we got new irl640 fets for injectors (they are similar to recommended irF640 but can be controlled without driver directly from atmega) - can we use them for ignition also? so we can simply remove fets driver (irl's will not like +12 on gate), igbts driver (same reason), place wiring from atmega's pins to fet's gates and make some pull-downs instead of pull-ups (and also disable "inverted" setting in config for ignition)?
irl640 is reasonable fast 11-17A current 200V fet, so it seems to be ok with bmw m50 coils, but i don't catch why everybody says that ignition _must_ be powered up with igbts but not fets  ::)

[orlovsn]

and another question added - it appears that firmware is compiled with FETDRIVER_INVERTING by default, and to drive logic level fets i need FETDRIVER_NONINVERTING
when i try to recompile it (1.1.88) i get "no rule to make 'vems.elf'", perl (activeperl) and WinAVR (20100110) are installed and both are in %path% list
if i edit avr_make and remove *.elf from 'all' rule i get no errors (Errors:none at the end) but no new vems.hex also  :-\
i've heard i can change my config's h[] table instead of recompiling firmware - so if it was
h[0]=20 10 08 04 02 01 00 00
looks like i need:
(hex) = (bin) -> (inverted bin) -> (inverted bin)
20 = 00100000 -> 11011111 = DF
10 = 00010000 -> 11101111 = EF
08 = 00001000 -> 11110111 = F7
04 = 00000100 -> 11111011 = FB
02 = 00000010 -> 11111101 = FD
01 = 00000001 -> 11111110 = FE
00 = 00000000 -> 11111111 | 2 spare conns = FF
00 = 00000000 -> 11111111 |
---------------------------------
h[0]=DF EF F7 FB FD FE FF FF

but this fails - still +5V on inj outputs right after turning power on ((

[jrussell]

I don't know that you'll get a lot of help on this. I would suggest getting the unit fixed properly by contacting [email protected] if you're in Europe or [email protected] if you're in North America.

The FETs now don't need the injector driver, but it's there to improve the robustness and reliability.

The firmware source isn't available, that's why you can't compile with the edited makefile.

[orlovsn]

it will take much time (i can order new driver directly from local store but it will take whole week)
ok, seems like i'll simply place some inverter from 74 series temporary
p.s.

The FETs now don't need the injector driver

but you can't make them work properly without disabling inverted mode on atmega's output  :-[

[GintsK]

I suggest to restore ECU in its original state: use drivers for FETs and use IGBTs.
where you live? even for me in Latvia parts from Farnell arrives in one-two working days.

Gints

[orlovsn]

farnell's representative takes 2-3 weeks on delivery and finall cost is 5-10 times more than order from local stores
i've found drivers with 7 days delivery and will order them tomorrow if i'll fail finding similar from IR's (a lot of ir's drivers are in stock, and rest is only 2-3 days for delivery), for now i can simply run on 7404 inverter with irls
but let's return to question about fets in ignition - what is the reason to use igbts, when fets offer same voltage and current with same/higher speeds?  ::)