I really think my Arduino OBD-II adapter will be useful in this project.
I don't have much experience with OBD-II, other than I've got a bluetooth OBD-II reader that I picked up on eBay for a few bucks, and it reads everything just fine. Is there additional info that can be pulled out of the OBD-II connector that it can't see (different protocol?) that the arduino versions can do?
all PIDs that your car provides. The adapter provides power supply for Arduino unlike a Bluetooth or USB OBD-II reader. Also I spent time on developing and maintaining the Arduino library for this adapter.
I am going to embed I2C accelerometer and gyro-meter in this adapter soon.
So then why spend $60+ on building an arduino adapter if you can spend under $15 on eBay for a bluetooth USB adapter and a bluetooth OBD-II reader?
It would make sense if you're not using a PC - and you want the arduino to actually read & react to messages or something, but if you've got the PC right there, it's going to save you a lot of time and money to use off the shelf components. I -hate- making my own stuff, and only do it when I've got a very compelling reason to do so.... or if I'm being stubborn. ;)
Heads up on doing i2c with arduino - make sure you are either using a 3.3v arduino pro, or pick up a 5v to 3.3v IO board, or be prepared to integrate that into your PCB. Most arduinos run at 5v and most i2c devices run at 3.3v, and the communication doesn't work between the two without logic level conversion. You can see in my PCB design that I have a logic level converter board plugged in.
Yes I price my kit at $75, but that includes OBD-II adapter, an Arduino leonardo board, a SDHC breakout board, a 128x64 I2C OLED display module, as well as my efforts to develop the library and the sketch which are ready to use, and a free web service to render the recorded data into a nice chart. Can you get all these under $15 on eBay? Am I over-pricing? Also I am never forcing people to buy my kit. Everyone can just pick up my arduino library, use my chart rendering service, and make his own adapter.
That's a very good price Stanley for all that you are supplying. I know that setting up and getting everything working as it should is a big task let alone making the sketch too! Well done! SNO
Thank you SNOtwistR!
As far as the arduino and i2c are concerned, I looked around to try and find a nice 5v accelerometer and magnetometer in a DIP socket or on a breakout board without any luck. I ended up having to get 3.3v boards, and during testing they didn't work until I used the logic level conversion. I'm sure you can find 5v accelerometers & magnetometers, but the most popular ones out there are all 3.3v.