Simple TA based FreeEMS for Sean's LT1

[Fred]

In lieu of proper documents showing options and configurations and fixes for the Spin 1 Puma boards that Sean has in his cardboard box, and the fact that even if they magically appeared right now, it'd be too late to order parts, perform mods, and assemble them, we're going to run his car from a TA board with some aux circuits.

This thread is to document what we do, for our selves, and for others who want to attempt this.

Inputs:

Sean uses a partial OEM ecu to control the fuel pump and condition the inputs. The only two inputs that are not 0-5v are the IAT and CHT sensors. These require a bias circuit and some filtering. 2.x resistor for bias, 1.6k for current limit to cpu, some caps configured around these to provide a smooth signal. The puma setup is fine, as are OEM circuits, copy at will.

Outputs:

The OEM ECU is handling the fuel pump control for us.

Sean uses an LTCC e-dizzy unit with a 12k input impedance, so a simple 5v output is all that is required to hit the coils on his car. This is best provided by an XOR chip such that we can configure it up or down as required at a later date.

Sean's intention is to run each injector from a single protected logic FET, we'll order 8 of those (or more for spares) and the likely candidate is the vnp10n07 part which powered the volvo injectors, and the 4age injectors. Experience has taught us that these are not driven properly from the CPU port on a 1:1 basis, let alone on the 2:1 basis that we need to use for this iteration of the build. Instead of that, the FETs will be driven with low value current limit resistors and a line driver chip with the CPU driving two channels of the line driver from one pin through 1.6k resistors.

Shopping list:

1 x DIP8 XOR, part number: 74HC86
2 x DIP8 Buffer, part number: 74HC367
8 x Protected Logic FET, part number: VNP10N07
2 x 1/4w 1% OR BETTER accurate bias resistors of chosen value to suit GM sensors (2.2k, 2.4k, 2.7k are suitable)
N x small ceramic caps for filtering inputs 0.1uF & 0.01uF
16+ x 1.6k 1% 1/4w resistors (cpu to/from world)
10+ x 10ohm 1% 1/4w resistors (options for current limits)
10+ x 100ohm 1% 1/4w resistors (options for current limits)
10+ x 330ohm 1% 1/4w resistors (options for current limits)
10+ x 1k 1% 1/4w resistors (options for current limits)
10+ x 10k 1% 1/4w resistors (weak pull down option)

Clearly various caps and resistors are optional, the first 4 items are necessary, though, at the very least.

Fred.

[SleepyKeys]

Fred, thanks for taking the time to write this post. I'm a bit bummed that I still don’t have the docs I need to build Spin1. Not to bad mouth the missing efforts that went into Spin1(hey were all busy), but in the future I will not order another spin until there are decent docs for it. Will my spin1 boards end up glued to the ceiling in my garage? I suppose time will tell

Anyway I would like to add links to the items mentioned as well as a couple goodies.
1 x DIP8 XOR, part number: 74HC86
http://www.mouser.com/ProductDetail/NXP ... 5XkYh5Y%3d

2 x DIP8 Buffer, part number: 74HC367
http://www.mouser.com/ProductDetail/NXP ... VTYNT74%3d

8 x Protected Logic FET, part number: VNP10N07
http://www.mouser.com/Search/ProductDet ... VNP10N07-E

2x Board To Board Connector for TA Card.
http://www.mouser.com/Search/ProductDet ... 7-534998-5

-------------------------------------------------- Optional -----------------------------------------------------------------------------

2 x 1/4w 1% OR BETTER accurate bias resistors of chosen value to suit GM sensors (2.2k, 2.4k, 2.7k are suitable)
http://www.mouser.com/Search/ProductDet ... CT52R2201F

16+ x 1.6k 1% 1/4w resistors (cpu to/from world)
http://www.mouser.com/Search/ProductDet ... 71-1.6K-RC

10+ x 10ohm 1% 1/4w resistors (options for current limits)
http://www.mouser.com/Search/ProductDet ... CT52R10R0F

10+ x 100ohm 1% 1/4w resistors (options for current limits)
http://www.mouser.com/Search/ProductDet ... 2f4DC1000F

10+ x 330ohm 1% 1/4w resistors (options for current limits)
http://www.mouser.com/Search/ProductDet ... CT52R3300F

10+ x 1k 1% 1/4w resistors (options for current limits)
http://www.mouser.com/Search/ProductDet ... 1K0000FHEK

[Fred]

Woops, yeah, I forgot the DIL50 connectors!

I guess my spin1 will be running one more engine before it gets permanently attached to a car. Perhaps 4 engines (all on my board and in my hands) is it for spin 1. That'd be sad/crazy... I certainly won't be recommending anyone that I know or have influence over get anything until the docs are solid, either. I feel like sending each and every spin 1 owner a refund personally for misleading them :-(

I'm looking forward to running the LT1 with this! :-) I had better get back to the code and into your garage if we wanna see that this year ;-)

Fred.

[nitrousnrg]

Fred, thanks for taking the time to write this post. I'm a bit bummed that I still don’t have the docs I need to build Spin1.

I'm very sorry about that. If you have a tiny spare time could you ping me on IRC/mail/whatever to discuss what would you have needed? I know its too late, I think I never felt the documents were so bad (yeh, I cant be imparcial here). The smallest feedback would be most welcome :-)

but in the future I will not order another spin until there are decent docs for it.

And is a sensible choice, to which I agree.

Will my spin1 boards end up glued to the ceiling in my garage? I suppose time will tell :)

I hope not, but if you feel better... I have some spin1's working as paperweight.
It would be nice to see you rinding on application-specific hardware once you guys get the LT1 code stable. I feel kinda bad about this, so I won't disturb the LT1 dev with late hardware topics when everything is happening around the code.

[Fred]

Sean and I would like to put power + comms + cpu + sm on his boards before I leave (and take one with me for bench testing). If you can help us with that, perhaps by making that section of the instructions perfectly clear and awesome, that would be something of a salvation.

Thanks for your comments.

Fred.