Bluetooth ELM 327

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Mark Dalton
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Bluetooth ELM 327

Post by Mark Dalton »

Is it possible to use a Bluetooth ELM 327 Device for RPM data when using the Diagnostic Software. I paired my Bluetooth ELM327 device with my PC and the PC allocated the Bluetooth device a COM Port (COM Port 6). The diagnostic software would search for the device. It would then find it but very quickly switch back to searching for the device again. It continued on in this loop for 10 minutes before I gave up. Is there a setting I can change in a config file or similar that I can set a specific COM Port.
I don't believe it to be an issue with the ELM327 adapter as I can use it to communicate with the car using other applications.

Steve Smith
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Re: Bluetooth ELM 327

Post by Steve Smith »

Hello Mark and thank you for the post.

I have been experimenting today with the ELM 327 Bluetooth device and I have to say I have managed to connect to the vehicle and obtain engine and road speed data, but it was not as simple as it may sound.

I do like the idea of a Bluetooth device for OBDII data capture as it removes cables around the pedal box area which is a blessing in itself.

I have been using a Windows 8.1 Laptop with PicoScope version 6.11.5 (Beta)

Could you confirm you are using the same beta version?

Could you confirm the ELM device to be installed correctly along with the relevant driver in the device manager of your PC?

Could you remove any devices that are using COM Ports lower than COM Port 6. (E.g. Other Bluetooth devices)

If all the above are OK, could you open the NVH software and enable OBD Logging (See image below)
ENABLE OBD LOGGING.jpg
Could you then run through the connection procedure as you have mentioned above to generate the identical symptom?

Once you have confirmed the OBD II connection error could you close the NVH program and PD?

This will generate a trace file containing detailed information about the connection to the OBD socket and enable the engineers to assist with an explanation.

The trace file is located here at:

Windows Vista/7/8: C:\Users\\AppData\Local\Pico Technology\Pico Diagnostics

With the Pico Diagnostics folder open, you will find a larger folder identified by a long alpha numeric title (E.g. a6f37be2-ef55-40fe-914d-ddbe5251)

Open the above alpha numeric folder and locate the “trace xml” file for the last NVH connection attempt. (Identified by the date and time alongside)

Could you then email this file across to me here at support@picotech.com

I hope this information is of some help, take care.....Steve

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Mark Dalton
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Re: Bluetooth ELM 327

Post by Mark Dalton »

Hi Steve,
Ok, so I don't know what I've done differently from the other day when I tried this, but when I tried it today it worked Ok, no problems, dead easy.
I'm using a Windows 7 machine and a non-beta version of the Diagnostic Software. I'll attach Docs below for you to look at.
I was able to connect with the ELM327 Adapter set as COM Port 4 and COM Port 6. I was able to replicate my result on another Windows 7 laptop.
My own Tablet is the only other PC in the Workshop that is not Windows 7, it's a Windows 10. But I can't test the Adapter with my machine just now because I having dramas with the NVH plugin (topic10971.html)
Attachments
trace.xml
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1st. Laptop.pdf
(365.13 KiB) Downloaded 612 times

Steve Smith
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Re: Bluetooth ELM 327

Post by Steve Smith »

Hello Mark, great news this is working now.

It kind of rings true throughout the building here that those who have tried the device find it clumsy to connect and temperamental at best

It will be interesting to see how you proceed with the Bluetooth ELM device and whether or not the sporadic nature of connectivity leads you to purchase the OBD II lead instead.

Thank you for the trace files, I will attach them to a bug report and await the response from the software team.

Take care......Steve

csasziszerviz
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Bluetooth ELM 327

Post by csasziszerviz »

Good morning!

Sorry, but i'm not the best in english language.

I would like to ask you, where can I buy good ELM327 ? I need only hardware with driver, or I have to download any software for that? Know anybody a good shop which post it to me or a good seller in ebay etc.?

My other question is that: if I will know the real engine rpm and vehicle speed at the measuring with ELM327, how to give in the alternator, water pump, servo pump, etc. rpm in the settings. I need ratio eg. crankshaft pulley diameter/alternator pulley diameter, or I need exact size in mm?

I hope you understand what I would like to ask.

Thank you! Have a nice day!

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Mark Dalton
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Re: Bluetooth ELM 327

Post by Mark Dalton »

The ELM 327 that I bought was just from ebay, long as you don't go for cheap ones you should be ok.The drivers are just generic bluetooth drivers.

Steve Smith
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Re: Bluetooth ELM 327

Post by Steve Smith »

Thank you for the continued posts

Regarding the Diameter/Ratio entries for alternator and water pump pulleys etc.

Within the NVH software settings, click on the Vehicle Information tab and then the Advanced button
NVH RATIO ENTRY-ADVANCED OPTION.jpg
This will open the Advanced Vehicle Settings box where you can add Transmission Ratios/Pulley Diameters/Ratios.

(Note here that these can be added post capture if this specific data was not available at the time of test)

Entering Pulley diameters requires specific manufacturer data if available or alternatively (as you suggested) a physical measurement of the suspect pulley's

The unit of measurement is not important here as long as all units are the same.

For example metric:
Engine speed 1000 rpm
Crank Pulley 150 mm, Enter 150.00
Alternator Pulley 75 mm, Enter 75.00

Remember the formula Driven / Driver to calculate the drive ratio

Alternator pulley 75 mm (Driven) / Crankshaft pulley 150 mm (Driver)

75 / 150 = 0.5:1
Engine speed, 1000 rpm / 0.5 = 2000 Alternator speed, 2000 rpm

Alternatively Imperiall
Crank pulley 5.9 Inch, Enter 5.90
Alternator pulley 2.95 Inch, Enter 2.95

2.95 / 5.9 = 0.5:1
Engine speed, 1000 rpm / 0.5 = 2000 Alternator speed, 2000 rpm

Should you wish to enter the ratio between the Crank Pulley and Alternator Pulley:

Here you would enter the value 1.00 for Crank Pulley and 0.5 for Alternator Pulley

I hope this helps, take care......Steve

csasziszerviz
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Re: Bluetooth ELM 327

Post by csasziszerviz »

Thank you Mark and Steve!

That was a very useful post and picture of the program.
I've tried it, and this is working well. Now I have to buy ELM 327 and start measuring better, than fix rpm.

When you use the equipment on a road test, where you can find a good transmission and differential ratios? I can't find a good and cheap software for this sizes.

Thanks the help!

Steve Smith
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Re: Bluetooth ELM 327

Post by Steve Smith »

Thank you for the post and a very good question.
where you can find a good transmission and differential ratios?
From experience various manufacturers appear to have mixed access to such data.

Some have everything you need to hand, others have to dig and delve into transmission codes and build dates to obtain the data required.

I have to say the internet remains invaluable again here as I have been able to obtain a number of ratios using an internet search right down to transmission codes and build dates.

Remember if you have obtained road speed via OBDII, entered the tyre sizes and differential ratio, this will be enough to identity all Tyre and Prop-shaft related vibrations. (No transmission ratios required)

Remember the ratios can be entered post capture to assist with the identification of unknown vibrations if the noise/vibration detected is relevant to a particular gear position.

I hope this helps, take care.......Steve

volrem
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Re: Bluetooth ELM 327

Post by volrem »

Hi

I just had problems getting bluetooth ELM to work with Pico. It worked with OBD software but Pico could not find it.

Tried several things but nothing helped. Until I rebooted my computer.

I rarely shut down / reboot because usually it just goes to sleep. But after reboot it worked great.

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