Sloppy Boost Controller

This is an open loop, arduino based, electronic boost controller. Basically, this device allows you to turn up and down the boost levels from within the car electronically. It does not currently have the capability to set target boost levels (closed loop). It uses a MAC solenoid mounted on the wastegate to do this. A lot of the components I used in this build are from stuff I had laying around. Don't be afraid to deviate from the instructions and make it your own.

Step 1: Parts List

Here is a list of parts I used for this build along with the supplier and cost.

Step 2: Wiring

Here is the worlds ugliest wiring diagram (if someone wants to make a better one, please do). It looks like a lot, but just follow the diagram and take it one component at a time.

1.I hacked up a car usb charger to converter the cars 12-14V power to 5V the arduino runs on. Here is a detailed link I used. There is probably an easier way, but this is how I did it.

2.Transistor. The left terminal gores through a 2.2kohm resistor before pin d10 on the arduino. The middle terminal goes to the black side of the diode. The right terminal goes the 12V ground terminal on the voltage regulator board.

3.Diode. The silver side of the diode goes to the positive 12V terminal on the voltage regulator board. The black side of the diode goes to solenoid ( along with the transistor in step 2).

4.Solenoid. The other solenoid wire goes straight to the positive 12V terminal on the voltage regulator board.

5.Buttons. Wire the grounds of all 3 buttons together and connect to GND on the arduino. Wire the other side of each button to pin D6 D7 and D8 respectively.

6.Screen. The Vcc terminal on the screen goes to 3V3 on the arduino. The GND terminal on the screen goes to GND on the arduino. The SCL terminal on the screen goes to pin A5 on the arduino. The SDA terminal on the screen goes to pin A4 on the arduino.

Wow those are terrible instructions... good luck.

Step 3: Setting Up the Arduino

I am assuming you have some experience with arduino before attempting this project.

The arduino nano from the parts page requires that you download a driver to let the arduino software recognize it (the reason is because these are not name brand arduinos). It's not difficult to do, just important to remember. Just follow the info on the amazon page.

Download the PWM and U8glib library (attached) and move it to your arduino library folder on your computer. The next time you open the arduino software it should appear in your list of libraries. The screen I used uses SH1106. You may have to change some of the code if your display uses something else. Here is a link to a video showing how to add arduino libraries (it has some groovy music!):

Also attached is the arduino code in .ino and .text. Use whatever is easier for you.

Upload the code to the arduino (which may take some time) and you should be ready to go.

Step 4: Housing

This is were you'll have to get creative. You can purchase a housing like the on listed in the parts list or you can cobble one together like I did.

The silver bezel is from an old wideband gauge. This is what the display and buttons are glued to.

The black back portion is the cap of a black spray paint can. It just happened to be the perfect size to hold all the components and match the diameter of the silver bezel.

The three buttons are on a piece of PCB that I cut with a dremel. I then glued the PCB to the display and bezel to keep it from moving.

I also have the usb end of the arduino sticking out the back of the housing so I can upload new code without taking it apart.

Cram all the wires and components into the housing and and close it up!

Step 5: Operation

Electrical polarity for the MAC solenoid does not matter. It can be hooked up either way.

Connect the (+) and (-) 12V leads to a "key on" power source with an inline fuse.

Once the unit is powered up, the sloppy raccoon will appear for 5 seconds. Then you can adjust the boost pressure down with the pin 8 button and up with the pin 7 button. The display shows percent duty cycle (0% to 100%). The value changes in increments of 10%. The pin 6 button is used to store a boost level in memory and return to 0. If pressed again, the boost level will return to the stored value.

At the high and low end of the scale, the solenoid reaches a saturation point. This is because arduino is sending electrical pulses too fast for the solenoid to react. The values will be different for everyone depending on your solenoid.

Step 6: Thanks!

The inspiration for this project came from Dale Follett. If you want to buy something similar to this unit without the hasle, Dale over at sells units similar to this. He is selling them for a really good price. He's a good guy and also has a lot of cool arduino projects in the works.

If anyone wants to pitch in a couple bucks to support upgrades and updates in the future, you can use the link below. If you have any specific requests, PM me your ideas. I would like to hear them. The wilder the ideas, the more beer money helps out!




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