brentil

Did some forum and google searching and haven't found my exact answer yet, was hoping some of you guys here could help me out.

I'm not exactly sure how to do the math but I want to be able to sample 5hz (5 times per second) data from the OBDII port on a modern 2007 car (Pontiac Solstice GXP). I know I can do it for sure via USB cables but I want to use BlueTooth in order to eliminate cables and for ease of removal/addition of the system I'm designing.

I know the newer ELM327 1.2 says it supports 500,000 baud but most of the BT items i see talk about using slower baud rates to connect to the device on the other side. Would this be fast enough for say 5~10 items scanned every 1/5th of a second?

Are there any BT OBDII scanners that can handle my data rates?

michbound

The bluetooth modules use the SPP (serial profile) and will not go faster than 128Kbps, you would be lucky to get much past 56K...

Paul
www.obdpros.com

brentil

Well I know the MTK GPS chipset connected to a PC via BT at 34Kbps uses 16.7% of the usable bandwidth at 1 hz transferring NMEA data and ~84% at 5 hz. So I'm hoping that doing OBDII with about 10 parameters will not use more bandwidth than a GPS module at 5hz for data transfers. If I can get 56K then I think I can do 5 hz hopefully. I just want to be able to retrieve data, I don't plan on doing any complex upstream commands besides just sending requests to get the data. It'll be the exact same data each cycle too.