Brainstorming potential aftermarket microcontroller/Arduino/etc based modifications

[cr08]

More recently I have been mulling over a couple of potential electronic modifications to the C-Max that will all rely on CAN communication likely with some form of compact microcontroller/Arduino type setup to accomplish it.

 

Right now nothing concrete started on these. Mostly just brainstorming the ideas so far and laying out some outlines of how I'd want to approach things. This thread, like a few of my others, is mostly to share these ideas and get them out there in writing. If anyone else is interested in toying with these, absolutely be my guest!

 

Low gear brake lamp activation:

A lot of new hybrid end electric vehicles when in heavy regen or whatever their low gear may be, will actively trigger the brake lamps without the brake pedal itself being used. The C-Max does not have this and I feel this is a huge safety issue. After playing around with Forscan and reviewing wiring diagrams, it does appear the BCM in the C-Max can activate the brake lamps fully in software as well (interesting enough, it has full PWM control and can adjust the brightness to any level 0-100%. Forscan has a control option with a nice brightness slider you can play with at the individual lamp level). Sadly no configurable options I can find for an actual low gear/regen brake lamp activation and was likely overlooked.

 

Some logic conditions I have in mind for this:

• Only active in L
• Use a sensitive accelerometer in the micro or as an addon to sense G forces. I believe this is how Tesla handles theirs. I need to look into specifics and if the actual G force level is documented anywhere.
• If the actual brake pedal is depressed, cut off the automatic portion of the brake lamp activation (unsure how the two will coexist if trying to trigger simultaneously. This needs more testing)

 

Pedestrian alert sounds: Again comparing to modern hybrid and electric vehicles here. Only recently has it been mandated to have external sounds generated at low speeds with the ICE off. Obviously the C-Max in all model years never had this. I think this would be a fun project to try and add that in and as a bonus have the ability to do custom sounds. One nice thing I've found is for newer Ford models with this, they have a 'weather-proof' speaker that sits either in the front or rear of the vehicle on the outside. It appears these are dumb speakers and just have basic +/- analog audio connections that go back into the cabin to a separate module that generates the sounds. Barring trying to find a place to mount it, this sounds like an ideal part to use here.

 

Logic conditions in mind:

• Only active in any gear but Park
• Monitor vehicle speed, only active under 25mph
• Deactivate when ICE is active. Optionally may include when the AC compressor is running since that is quite buzzy and audible.
• Optional: Include some reverse specific alert sound active while in Reverse only (obviously)

 

Personal goal: Keeping the sounds minimally jarring or annoying. I do have auditory sensory issues myself so keeping the sounds less annoying is a top goal for this.

 

Additional battery cooling (Energi): This has been something that has been on the backburner for a while but I haven't really documented in full. Given the Energi's known thermal management issues with the hot exhausted air from the battery being sent back into the cabin (in a poor fashion at that), adding extra airflow or a more directed airflow outside of the vehicle would probably be a big help. I have a 12v high CFM blower that is built to be easily ducted that I have used for other projects and would probably be very useful for this. The hopeful goal is to be able to redirect the air through the louvres in the rear that let extra air flow out of the vehicle. Also the goal is for this to be intelligent to operate only while charging or while driving and the battery temp reaches a predetermined point and bypass Ford's own programming that keeps the stock cooling fan off until the temp reaches more than 20 degrees above the cabin temp.

 

Logic conditions in mind for this:

• Trigger when plugged in and the on board charger is actively providing 12v/accessory power. While not charging (running Value Charge for example) only activate when the battery is at an elevated temperature but ONLY as long as the cabin temp stays within a certain range compared to HVB temp. I don't think there's much use trying to force cooling if the cabin temp is above battery temp. But may have to experiment to see if it continues to help in any way.
• Add some PWM control to adjust the speed based on battery temp.
• Optionally see about running this while driving, bypassing Ford's '20 degree' differential programming. The PWM control would come in very handy here to keep noise down.