So this pretty much is just a sharing of the history and the open source materials for this project that I started back in 2010. I’m Duke3k - I live in the foothills of Denver and I’ve bought so much stuff from Sparkfun and been to their factory/offices in Boulder to pickup orders enough times I’ve lost count. If any SparkFun folks see this - tell Nathan there is an easter egg waiting for him in source code posted on http://www.renegadetechworks.com. 
SparkFun *was one of the major drivers as to why I’ve decided to Open source this project and so I thought this forum was a good place to share so here goes.
I(we) own a couple of these :
http://renegadetechworks.com/images/Sli … 033_LR.jpg
They are mint Mitsubishi 3000gt VR4’s. The one on the right is my '98 VR4 & the One on the left is a super rare '95 Spyder Convertible Version that is my wife’s.
So here’s how this project got started:
The early model Mitsubishi 3000gt VR’s (including that '95) have a factory included Electronically Controlled Suspension system. It was pretty much over the top and kinda ahead of it’s time. It has as sensor inputs to the ECS controller - a single axis G-sensor ,a Throttle input, Steering Wheel sensor inputs, Brake Pedal input, and a user selection switch on the console. With all those inputs the factory ECS controller controls the 4 adjustable shocks(struts) in the car. Each strut is capable of being commanded by the ECS controller into a Hard , Medium or Soft setting that primarily adjusts the Shock Rebound dampening rates on the fly. There’s a motor (not a stepper) that is physically inside the strut that when power is applied rotates a shaft and changes the orifice opening size thru which strut hydraulic fluid squirts thru. the bigger the opening more fluid flows thru on rebound = softer rebound = smoother rider. Smaller opening = less fluid thru orifice on rebound = stiff sporty suspension.
Mitsubishi completly eliminated the system starting in late '95. So My '98 did not have it when I bought it. 
This bugged me to no end - so I decided that I wanted to retrofit in this controllable suspension system into my '98. My car has none of the sensors , none of the factory wiring harness feeds necessary and the struts that were in it were the later model fixed rate struts - not the controllable ones.
What I decided to do was to remove the non-contrable factory struts & replace them with the controllable ones and then build a manual controller to control the struts (skipping the sensors ) .
Back in 2010 I had not messed with Microcontroller much so this was my first design (that I never ended up using )based on TTL circuits - it’s only enough circuit to control one strut:
http://renegadetechworks.com/images/his … t_v2r2.jpg
Here’s the actual design prototyped on a breadboard and I got it workding. You can see the bread board connecting to the test factory ECS strut cartridge that I use. It’s connected via a spliced cap connector plug that plugs into the top of the factory strut. It has five connections - Motor, Signal Switches S1 & S2 and two ground wires. :
http://renegadetechworks.com/images/his … LowRes.jpg
While the TTL circuits worked they would have been difficult to easily add behavior/code changes. A much better alternative was a micro controller based solution So I dove into the arduino platform and went with the Standard Arduino for the time period - the Duellimanov Amtel328 16mhz 32kb.
What I finally came up for the design was this hand drawn prototype design that could be used to build an Arduino Shield.
The shield was used to build out the strut driver circuits using a TI SN754410 quad H-Bridge Motor Driver chip
The Control Selector Switch was a 5 position Rotary Selector Switch that I use to create a Voltage divider that fed into one of the analog ports on the Arduino.
Four BlinkM I2C addressable RGB leds were used as strut & diagnostic status indicators .
Each strut had 5 wires going to it (9v Motor Power Wire, 2 Grounds and 2 internal status switches)
Each Strut used 3 ports each (12 total) to the arduino : 1- Motor Enable, & 2- Digital inputs for the status (open or closed ) of the S1 & S2 strut mode sensor switches.
http://renegadetechworks.com/images/his … cuitV4.jpg
That lead to this Arduino full on implementation that had a custom prototyped shield piggybacked onto it:
http://renegadetechworks.com/images/his … ielded.jpg
Here’s it is all buttoned up ready for installation:
http://renegadetechworks.com/images/his … oxedUp.jpg
Here’s all the final pieces of the custom Arduino Based Build assembled & being tested including the console controls/display. -Thats a 4 position rotary switch for the mode selection. & those are 4 addressable I2C BlinkM LEDs that display the strut status/diagnostic info.
http://renegadetechworks.com/images/his … ontrol.jpg
Here it is installed in the back of my 3000gt, I used cat5 for the five runs of wire needed to make the wiring harness to retrofit into the car. ( 4 runs to each of the struts and 1 run to the console control display & lastly a switched +12v power and ground feeds. Oh and you gotta love Gorilla tape. … I was stil debuging & i didnt want to keep messing with the screws.
http://renegadetechworks.com/images/his … lledLR.jpg
And that’s the way it was for two years…I ran with that custom build in my car… I fairly regularly attended the local car meets for the 3000gt’s in the area and kept getting asked - hey when are you going to make these so that we can do that too? Well around 2012 - I got motivated and came up with this custom - all one board solution:
http://renegadetechworks.com/images/Ope … erview.png
Here’s the production version of single board design - its basically an AMtel328 arduino simplied design with the additional circuitry that used to be on the shield piggy back :
http://renegadetechworks.com/images/his … ECS_LR.JPG
And here’s a you tube Vid of the production build being demonstrated from the console of the car. In the final production version I switched from the 4 I2c controlled BlinkM leds to a simpler set of 4 - WS2801 chained 12mm Pixel Leds. You"ll see the WS2801’s in the video.
http://www.youtube.com/watch?v=_sI4AgXFdh0
I started selling these in Sept/Oct of 2012 and have shipped them as far as England & Australia. One major design addition that has made them popular is that they are plug compatible with original OEM ECS controllers - so if your an early model 3000gt owner and your factory controller dies you can replace it with a TechWorks controller (for $100 cheaper). Manual control only - but a lot of people like it that way it turns out.
Well thats it. Hope you enjoyed the story. If your interested - all the Arduino open source code and electrical schematics are available for download on http://www.renegadetechworks.com
Cheers,
Duke3k
p.s. Nate anytime you want to claim that “beerware open source license” - just let me know and I’ll drive up and pay my dues .
