Hello! I'm looking for information how to send commands to the popular ELM327 OBD interface. I want to design a stand alone device that check long term fuel trim values along with some other parameters. Is there a good guide somewhere how those commands are set up? Thanks in advance
How to send commands to ELM327 OBD interface
Started by ●November 24, 2012
Reply by ●November 24, 20122012-11-24
It looks like the device you buy is just a packaged version of the chip and a bit of glue electronics. Is the actual datasheet useful?> http://www.elmelectronics.com/obdic.html
Reply by ●November 24, 20122012-11-24
On Sat, 24 Nov 2012 14:28:47 -0800 (PST), powerampfreak <powerampfreak@hotmail.com> wrote:>I'm looking for information how to send commands to the popular ELM327 OBD interface. I want to design a stand alone device that check long term fuel trim values along with some other parameters. >Is there a good guide somewhere how those commands are set up?<http://en.wikipedia.org/wiki/ELM327> List of commands: <http://www.elmelectronics.com/ELM327/AT_Commands.pdf> The real product page: <http://www.elmelectronics.com/obdic.html#ELM327> (Note that v1.5 chips are all unlicensed clones). Make your own ODB2 board: <http://www.elmelectronics.com/obdusers.html> Ideas and code: <http://wiki.tinyclr.com/index.php?title=Vehicle_OBD_-_ELM327> etc.... Google for "elm327 source code". -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
Reply by ●November 25, 20122012-11-25
Great guys! ELM327 is a pre-programmed PIC processor. It communicates by RS-232, so probably I can set up another PIC through the USART and communicate with the ELM. And possibly use a 2x16 char LCD display to show the parameters. Brill !!!
Reply by ●November 25, 20122012-11-25
On Sun, 25 Nov 2012 00:44:42 -0800 (PST), powerampfreak <powerampfreak@hotmail.com> wrote:>Great guys! >ELM327 is a pre-programmed PIC processor. It communicates by RS-232, so probably I can set up another PIC through the USART and communicate with the ELM. >And possibly use a 2x16 char LCD display to show the parameters. Brill !!!This forum and article might be of some help. "free OBD2 software with MPG calc" <http://ecomodder.com/forum/showthread.php/free-obd2-software-mpg-calc-7490.html> Incidentally, I bought a Mini ELM327 BlueTooth on eBay to play with. The plan was to leave it plugged into my vehicle OBD2 connector and have it communicate performance numbers via BT to my Droid X phone while driving. The plan was ruined when I found myself with a dead car battery the next morning. It seems that the Mini ELM327 does not turn off when the ignition key is off, and continues to draw power. Actually, it drew enough power to get hot enough to partially melt the blue plastic case. A quick survey of other such devices indicates similar problems. I had to crack the case to install an on-off switch. -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
Reply by ●November 25, 20122012-11-25
I wonder if it was defective? Maybe it latched up. Otherwise, can you just hyperterminal to it and play around?
Reply by ●November 25, 20122012-11-25
On Sun, 25 Nov 2012 09:35:32 -0800, miso <miso@sushi.com> wrote:>I wonder if it was defective? Maybe it latched up.Nope. It still works. The eBay vendor was nice enough to sell me another one for essentially the cost of shipping as he was interested in the problem. The replacement did the same thing. Mine is similar to this one: <http://www.ebay.com/itm/160902620405> There are several other form factors including one that's even smaller. I've tried two larger flavors, and they also don't turn off with the ignition key.>Otherwise, can you just hyperterminal to it and play around?Probably you could. BlueGoof nicely emulates a serial COM port so any terminal emulator should work. However, it might be easier to just buy an RS-232 ELM327 device. I hope you enjoy typing AT commands. There are apps to make it easier: <https://play.google.com/store/apps/details?id=Scantech.Terminal&hl=en> -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
Reply by ●November 25, 20122012-11-25
Jeff Liebermann wrote:> > On Sun, 25 Nov 2012 09:35:32 -0800, miso <miso@sushi.com> wrote: > > >I wonder if it was defective? Maybe it latched up. > > Nope. It still works. The eBay vendor was nice enough to sell me > another one for essentially the cost of shipping as he was interested > in the problem. The replacement did the same thing. Mine is similar > to this one: > <http://www.ebay.com/itm/160902620405> > There are several other form factors including one that's even > smaller. I've tried two larger flavors, and they also don't turn off > with the ignition key. > > >Otherwise, can you just hyperterminal to it and play around? > > Probably you could. BlueGoof nicely emulates a serial COM port so any > terminal emulator should work. However, it might be easier to just > buy an RS-232 ELM327 device. I hope you enjoy typing AT commands. > There are apps to make it easier: > <https://play.google.com/store/apps/details?id=Scantech.Terminal&hl=en>Or the USB version to use with a laptop: http://www.ebay.com/itm/150954172607
Reply by ●November 26, 20122012-11-26
On 11/25/2012 10:40 AM, Michael A. Terrell wrote:> > Jeff Liebermann wrote: >> >> On Sun, 25 Nov 2012 09:35:32 -0800, miso <miso@sushi.com> wrote: >> >>> I wonder if it was defective? Maybe it latched up. >> >> Nope. It still works. The eBay vendor was nice enough to sell me >> another one for essentially the cost of shipping as he was interested >> in the problem. The replacement did the same thing. Mine is similar >> to this one: >> <http://www.ebay.com/itm/160902620405> >> There are several other form factors including one that's even >> smaller. I've tried two larger flavors, and they also don't turn off >> with the ignition key. >> >>> Otherwise, can you just hyperterminal to it and play around? >> >> Probably you could. BlueGoof nicely emulates a serial COM port so any >> terminal emulator should work. However, it might be easier to just >> buy an RS-232 ELM327 device. I hope you enjoy typing AT commands. >> There are apps to make it easier: >> <https://play.google.com/store/apps/details?id=Scantech.Terminal&hl=en> > > > Or the USB version to use with a laptop: > > http://www.ebay.com/itm/150954172607 >Actually, I need the Nissan/Infinti proprietary connector. Maybe a converter exists, but the damn SEO brings up catalytic converters when I do a search.
Reply by ●November 26, 20122012-11-26
On Sun, 25 Nov 2012 21:42:15 -0800, miso <miso@sushi.com> wrote:>Actually, I need the Nissan/Infinti proprietary connector. Maybe a >converter exists, but the damn SEO brings up catalytic converters when I >do a search.<http://www.amazon.com/OBD2-Connector-Diagnostic-Adapter-NISSAN/dp/B0053NS0CY> <http://www.ebay.com/itm/220853326527> Found in a few seconds with Google searching for "OBD2 Nissan adapter". -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
