Puma board for FreeEMS

[hamster]

Ah, that's cute. I hadn't seen them before.

Most MOSFETs need about 15v to fully switch, but some are 'logic level' and will switch at 5v. MOSFET drivers usually have a logic side and a drive side with different Vccs to allow for this.

[hamster]

I was digging around online and found this interesting little appnote from Freescale on building a DCI ignition with a HC08, using an IGBT. Might be an interesting source for some ideas: http://www.freescale.com/files/microcon ... AN2159.pdf

Also, using IGBTs for ignition from ST: http://www.gavner.se/files/igbt.pdf

[davecramer]

Ok, I suspect a BDM connector is for debugging, am I correct ?

[Locost_Johnh]

Dave,

I'm new to this stuff too. Found this about BDM's:
http://en.wikipedia.org/wiki/Background ... _interface

Enjoy,

John

[nitrousnrg]

Hi John, hamster
I'll use BDM to flash the bootloader in the microcontroller.

This may help:
http://forums.freescale.com/t5/TBDML-Tu ... /td-p/5729
(ctrl+F for "program")
Good pdfs hamster! I'll take a deeper look at them later

BTW, my BOM is almost ready. The components order is scheduled for October 4th. I'll share the .csv file as soon as it is ready.

I stopped routing, the plan is to try the circuits and check they behaves as I wish. Ah, LM1815 are out of stock, so I changed them for a few MAX9924.

[Fred]

Marcos, do you have something to hardware invert the ignition outputs? This is required because it will NOT be configurable in software. It isn't that we couldn't do it in software, it's that it's a bad idea to do it in software. Doing it in software means that the reset and bootloader states can be dwelling instead of floating. You need to have some sort of inversion mechanism, such as an XOR gate, I think. Does that make sense? There are threads on this stuff. You could set it up on yours with a press on jumper PC style. Or it could be on a per order basis solder bridge between adjacent pads. One jumper should configure all ignition outputs, though, really.

Fred.

[nitrousnrg]

I didn't have anything. I thought that the gates were there because of the unknown initial status of some pins (and I believe that behavior can be corrected)
Well, since they are there to give support to other types of ignition modules, I'm adding a quadruple XOR gate (74HC86DR2GOSCT-ND @ digikey).
Default: active on 1. Active on 0 soldering 2 contiguous pads.

Thanks for pointing that out.

Sorry for the delay, it took me a while to think about other variants.

[Fred]

I think if it's to correct for the pin states, then it's got to be tri state buffers, or something like that. There is a thread, complete with conclusions somewhere. I wouldn't be to sure about the reset pin state behaviour, it might be sortable, but it might not too.

I should try to dig up that thread for you, but I'm feeling a bit tired after yesterday's marathon effort.

Fred.

[Fred]

http://www.diyefi.org/forum/viewtopic.php?f=41&t=365

8 pages of solid discussion there! RPM inputs could be in the same boat, I don't have time to re read, but just be aware that anything could happen and that it's still under heavy dev with rapid change in behaviour. (which is why I keep suggesting to wait hardware wise...)

Fred.

[nitrousnrg]

No worries. Its just one or two prototypes, and they are intended to start testing most of the circuits. Anyway, I want it as close as possible to the freeems standard.