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Post by xandasxurras on Mar 24, 2023 11:01:15 GMT
Hello to all. I´m quite interested in running a direct injection engine with a DIY ecu. I have been installing megasquirt Ecus during some time and I was even looking around to convert a port injection ECU in a direct injection ECU. (KMS had a GDI driver to connect as piggyback between Standalone Ecu (KMS on other) and direct injectors, also I though about using a MC33812 with a MS3/MS2.
First of all I am concerned about next difficulties:
Piezo/inductive injector differences. (Semi-Resonant circuit or coil current control circuit).
Diesel/Petrol injector differences. (Response times related to internal resistance, ergo current management).
Old/new direct injector differences. (No coding or simple color based coding/ code based in an alphanumeric code regarding: ON time, OFF time, Inertial, steady current, etc. (Google IMA injector decode)).
This last one could be a total challenge.
I am dreaming with running a diesel engine with a MS2 Ecu, which is of course all of this about but......I think I will still dreaming.
Anyway, there some chance of using your PF-DI in a megasquirt? I am studying this Rabbit project but I see a lot of new and different things, different PCBs, so many firmwares ,etc. I feel a bit lose. Megasquirt is more 'familiar' to me.
By the way, congratulations to all and keep working in this magnificent project.
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Post by Admin on Mar 30, 2023 12:51:41 GMT
Hi mate, Rabbit ECU direct injection right now works on the EA888 engine. The injectors are the solenoid type - they are around 2.5 ohm. From Rabbit ECU the peak current is around 12A and hold is around 3A. I am not so keen on using any OEM driver IC like MC33812 because of the supply issues. Rabbit ECU has bene burned by supply issues recently - so I think is better to use a generic solution with a range of parts! I am not sure if the PF-DI board can help - the interface is the Arduino Due footprint, which uses 3.3V signals. For example this is part of the PF-DI V3 schematic (see here github.com/RabbitECUProject/Sparkdog-PF-DI-V3): You can see the signals GDI1_SIG and GDI2_SIG - these are the on-time signals (3.3V) coming from the main controller. The PF-DI board uses these signals to output the switch-mode injector drive signal. Not sure how that could be used with MS3. I guess there is a chance it could work for an Arduino based ECU - mixing the parts together. I think there must be OEM GDI driver boxes available that can accept say a 5V drive signal and perform the switch-mode injector drive. Hope this info helps :-) Matthew |
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Post by xandasxurras on Apr 17, 2023 15:12:54 GMT
Sorry, I do not see what GDI1_SIG and GDI2_SIG are. High side or low side?What about boost converter?
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Post by xandasxurras on Apr 17, 2023 16:28:17 GMT
What software are you using? kicad, eagle? Version?
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Post by Admin on Apr 18, 2023 15:35:29 GMT
Hi, I am using Kicad Version 7. Maybe it is easier to view the schematics in PDF form. Here is latest attached so you can see the signals. The signals are for the GDI on-time for each pair of injectors (they are multiplexed). GDI1_SIG and GDI2_SIG are inputted into the microcontroller and the required HS and LS signals are outputted to the GDI drive circuit. Hope this helps, Matthew Attachments:PF-DI V3 SCHEMATICS.pdf (936.79 KB)
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