DIY Boost Gauge

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#1177
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#1
FYI - This is a re-post of a thread I started over on fiestast.org (here).

This project came about as I was researching boost gauges for the FiST. I had looked into a COBB Accessport, but wasn't ready to drop the $$$ for a tune/risk my warranty. After watching a review for the new WRX, I noticed that Subaru included a digital boost gauge in their software. It got me thinking - "How hard can it be?".

Then I remembered reading about a custom OBD-II/Raspberry Pi project on a blog (check it out here) and thought it would make a great end-of-summer project (I started this back in July). In addition, I'd have access to whatever vehicle data I wanted. The plan was to output this information to a 2x16 character LCD (example) for simplicity, and also because I managed to find one that matched the FiST's dash LCD pretty darn well.

In summary, the goals for this project are:
  • Learn how to code in Python
  • Learn how to output data from Raspberry Pi to LCD
  • Display diagnostic data from OBD-II (mainly boost pressure)
  • Don't electrocute myself
  • Don't start anything on fire

Helpful links (running list):


FAQ:
"Why not use Torque Pro? (OBD-II Android app) There's already been lots of development on that."
Since originally responding, I've actually utilized Torque Pro a bit and found it to be very useful! However, it was a bit "busy" for my tastes, and I use my phone for calls/music when driving. In addition, I have a 5" Nexus 6P, which I don't really feel like mounting to the windshield. Finally, I'm a software engineer by day, so the opportunity to learn a new programming language is a great opportunity to expand my skill set

"It would be cool if you could interface a pressure transducer to the Raspberry Pi and design a digital display without the need to occupy the OBD-II port!"
There are already quite a few projects I've found where this had been done. Also, I'm interested to see if there's any latency issues with utilizing the OBD-II interface.

Update 8/27/15:
Working Python script to grab the engine RPM:

[video=youtube;JbrFzkmqNC4]https://www.youtube.com/watch?v=JbrFzkmqNC4&feature=youtu.be[/video]

Update 9/10/15:
Supplies from Amazon arrive:


Everything wired up (attempt #1):


Unfortunately, this attempt resulted in a fried OLED display. Some wiring adjustments were necessary.

Update 9/21/15:
New display arrives, testing:


Python code working on Raspberry Pi:

[video=youtube;USFfg1GxvGw]https://www.youtube.com/watch?v=USFfg1GxvGw&feature=youtu.be[/video]

Update 2/7/16:
I updated my Python scripts to utilize the python-OBD library due to it's excellent documentation and expansive features/functions (i.e. RPM's, throttle position, boost pressure, etc.).

These scripts are running on the Raspberry Pi, outputting data successfully to the OLED display. I am now looking into wiring the Pi's power into the FiST, and am exploring the Mausberry 2A Car Supply/Switch.

Due to the way the Mausberry switch works, I need to tap three locations in the glovebox:
  • Fuse with a constant 12V supply (even when car is off)
  • Fuse with switched 12V supply (relies on ignition/accessory)
  • Ground
I'd welcome advice from anyone familiar with the 2014 FiST fuses as to which will work. I should note that I've already tapped the rear wiper fuse for my dash cam. It should be fairly easy to test the fuses myself, but I am concerned about a separate ground point. I'm currently using the screw located to the top right of the fusebox for my dash cam ground (seen here).

Update 6/29/16
I've got a blog post together here chronicling the entire project!
 


Member ID
#3375
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#2
Interesting. I'm gonna keep my eye on this.
 


OP
Manuel
Member ID
#1177
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31
Thread Starter #5
Well, almost a year later and I've got something to share!

[video=youtube;kVyh6FTyh9E]https://www.youtube.com/watch?v=kVyh6FTyh9E[/video]

I've been running a working version of the code in my car for a few weeks now with no major issues. There is still plenty of room for improvement (I've already started a list...), but I'm happy with how it's come together so far.

A publicly available copy of the code is available on my Github (here) along with some documentation to support the setup/usage of the project files.

I'll be working on a full blog/forum post to highlight the project start to finish, but for now feel free to share your comments/criticisms/suggestions!
 


Member ID
#4886
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#6
very cool.. this is inspiring. and makes me feel useless
 




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