MEFI-3 & 4 CAN Protocols

[KidTurbo]

Hi guys, been working on a little project for some of my boating buddies and could use a hand with the MEFI data side.

What I am working on is converting some proprietary CAN data from different ECU's to modern J1939, NMEA 2k, and other common protocols for use with digital displays, chart plotters, and modern gauge clusters. After playing around with some off the shelf Arduino stuff like the CANbus Triple, we opted to build our own high end gateways. Using twin opto-isolated CAN transceivers for BUS protection, and the ARM M4 processor to handle the translation duties. We also tossed in a BLE 4.0 modem for future use with APP's like Torque and such.

Prototype testing is finished and the first run of PCB's is complete. So far we've successfully converted Holley's EFI "Racepak" protocol and PGN set to J1939 and N2k format outputs. All those being 29bit broadcast protocols, was actually petty straight forward to get primary values like TPS, RPM, Temps and Pressure stuff working. Now I've been ask to do the same with MEFI and a couple others units.

Since I presently don't have a MEFI-3 or 4, a Merc scanner, or copy of MEFIburn to sniff packets from, I started looking for some related ALDL files. Guess where I landed, again... So if anyone would be kind enough to give me crash course in MEFI protocol, or links to anything relative before I go jack into one it would be much appreciated.

Also, here is a look our gateway. It has enough processor power to handle OBD-II type request based translations and forwarding faster than the typical BUS speeds if anyone has special projects that might benefit.

Thanks

-K

[rsicard]

Speaking of special projects, it would be nice to have open source CAN software written in Python modules. Would like to have the homebuilt EFI ECU spitting out CAN data acting as a engine/vehicle data concentrator feeding a TFT color display of the vehicle parameters. Would like to have bar graph type display of parameters to maximize usage of screen space. The old round boiler gauge dials take up too much space. The bar graph type display would yield quick glance of vehicle data.

So much for dreaming, what language did you use to write your CAN code? Likely will need MEFI 3 or 4 unit and apply stimulator and trap CAN data and decode according to stim inputs to MEFI. Just a thought. Press on with the project.

[KidTurbo]

Think the firmware is written in C. My embedded systems developer friend took the design specs and ran with it. Everything is being hard coded so far. We started this project to accommodate guys running dual high HP engines with aftermarket ECU's. While Holley recently released their own 7.5" display, they are not what ya call "marine friendly" or dual engine capable like the Garmin, Raymainre, and other specifically tailored to boating units. Because N2k and J1939 are basically the same thing with slightly different PGN's, the option to run off the shelf industrial units is there.

http://www.fwmurphy.co.uk/products/m...view_pv450.htm

[roughneck427]

I have a mefi 3 in my boat I use mefi burn tunerpro and I have some other flash ware that im using that's way quicker on the flash time on the mefi 3. TTSdata master also hooked me up with the windows 7 version licensed of the datalogger. Here is the thread on my build http://www.gearhead-efi.com/Fuel-Inj...EFI-tune/page2

PM me your email and I can send over the trial version of tts and some data logs.

[KidTurbo]

Mailbox is full.

Nice project, sure wish you lived closer. Would love to test with that data logger, it likely does everything we need to capture. One of the guys over on EFIlive forum started to convert the ALDL PIDs a while back, but never finished posting results. I've also been toying with the idea of doing a E67 conversion package to replace the MEFI-5 units with a more friendly software package.

[roughneck427]

I sent you an email. I saw your post on performance boats.com in the GN7 on the dyno sub forum. I sure do like the mefi once I got my boat dialed in. Its a strait fwd ecm and wasn't that hard to tune it especially being in a boat which is mostly on a load at all times.