Which ELM327 tool will work best with these 850's?

[pappatho]

I am using baud rate of 9600 since that is what the computer set the port to as a default.

I couldn't find anything on the port tab in Realterm to rescan the list of available ports.

[esl_97_850_T5]

pappatho,

1. The Realterm v2.0.0.70 "(double click to scan ports)" mechanism is nifty, but it's not intuitively obvious how to use it. Took me a while to figure it out.

See the reevaluate your particular Port # paragraphs at that online volvo850diag.html link. Else see the equivalent section in your local version of volvo850diag.html.

Else follow these instructions:

a. After displaying volvo850diag.html, answering some questions to allow volvo850diag to use ActiveX and scripting, clicking "Start Realterm", and successfully getting Realterm to display some ELM327 commands, click the Port tab.
b. Click the down-arrow to the right of the Port box.
c. Scroll to the "(double click to scan ports)" item in the Port pull-down list, then single-click or double-click it so that it appears as the Port.
d. Double-click the "(double click to scan ports)" that appears between the Port label and the pulldown list down-arrow.
e. In the resultant re-scanned port list, you might be able to see \BthModem0, \BthModem1, or some other generic port name (that the drivers then associate with a specific COM port # once you try to connect).
f. Select \BthModem0 if it is available, and see if the resultant chosen COM port # is the same one that you've been successfully using.
g. Click Open once, check the lower right corner to see that the port is probably still closed, then click Open a 2nd time.
h. Verify that (after the 2nd Open click) the lower right corner shows the port number, speed, data bits, parity, stop bits, etc.
i. Check if you can type ELM327 commands into the Realterm Terminal pane.

2. I'd be curious if your Bluetooth ELM327 can operate at 38400 baud.

NOTE: The baud rate attempted by Realterm overrides whatever baud rate is visible in Control Panel / Device Manager. For example, for my ELM327 clone USB cable, even if Device Manager says 9600 baud, if Realterm attempts to connect at 38400 baud, that ELM327 device successfully connects and communicates at 38400 baud.

Since the ISO 9141-2 comm between ELM327 and car is at 10400 baud (ie, > 9600 baud), it is advisable to have the ELM327 to/from computer comm occurring at 38400 baud to lessen the possibility of overrun errors. Since you've finally got your Bluetooth ELM327 working using the Windows Bluetooth stack, maybe it's time to try the ELM327 norm of 38400 baud again.

3. Are you using Realterm v2.0.0.70?

esl_97_850_T5

Edited: to add v2.0.0.70 ref and question.

[pappatho]

It looks like you still need to know the port.

If I click on 5=\Bthmodem1 it will work
6=\Bthmodem0 will not work.

Baud of 38400 in Realterm works.

[esl_97_850_T5]

pappatho,

Thanks for the info and the snapshot.

1. For the purpose of: a) helping me understand how to generalize volvo850diag properly for Bluetooth devices, and b) getting you setup so you never (or almost never) have to visit the Realterm Port display every time you click "Start Realterm", can you answer these questions...

- Do you know what your COM6 = \BthModem0 was used for?

- Do you know what your COM7 = \BthModem1 was used for?

- Do your COM5, COM6, and COM7 always equal \BthModem1, \BthModem0, and \BthModem3, respectively?

- Do you always use COM5 for your Bluetooth ELM327 connection? Or does it sometimes change to another COM port #?

- Do you always use \BthModem1 for your Bluetooth ELM327 connection? Or does the Bluetooth ELM327 sometimes use \BthModem0 or \BthModem3 ports?

2. As long as your Bluetooth ELM327 is either:

a) always a fixed \BthModemNN port (be it \BthModem1 or whatever), or
b) always a certain COMnn port (be it COM5 or whatever),

then volvo850diag.html can be made to use that fixed value.

Using your pappatho Bluetooth ELM327 case of COM5 = \BthModem1 as a specific example...

Solution 2A: Edit scanner_type to "ELM327-Bluetooth", then edit the associated Bluetooth oriented port_default from its distributed default of \BthModem0 to force use of \BthModem1 by editing this line:

port_default = "\\BthModem0"; // For a Bluetooth based ELM327.

to be:

port_default = "\\BthModem1"; // For a Bluetooth based ELM327.

then refresh (F5) volvo850diag.html.

Solution 2B: Simply make the 1-line change to hardcode the "port" variable by editing the following line:

var port = ""; /* Force Port # here. */

to say:

var port = "5"; /* Force Port # here. */

then refresh (F5) volvo850diag.html.

Solution 2C: Define the RT_ELM327_PORT environment variable via Control Panel / System / Advanced / Environment Variables window (or whatever the post-WinXP method is for doing this), then exit the IE instance which is running volvo850diag.html, then redisplay volvo850diag.html. This last method would not require any future edits to volvo850diag.html when new versions of volvo850diag are released.

3. However, if one time your Bluetooth ELM327 is COM5 = \BthModem1, then the next time your Bluetooth ELM327 is COM8 = \BthModem4, and the next time your Bluetooth ELM327 is COM23 = \BthModem45, then your situation is too variable for volvo850diag.html to be programmed for it. In that "always potentially different COMnn and \BthModemNN" case, you will very likely have to still resort to selecting the proper port on Realterm's Port tab.

esl_97_850_T5

[pappatho]

It seems to always use COM #5 for the ELM327. I previously was just typing a "5" into the port box in realterm. It looks like COM 6 and 7 may be associated with a phone.

I think I already had solution 2C set, but it wasn't working. Thinking about it more, maybe I never restarted IE. I guess I need to verify that.

[esl_97_850_T5]

pappatho,

Thanks for the screen shot. That's a useful teaching example.

1. As long as your Bluetooth ELM327 consistently uses COM5 and you have RT_ELM327_PORT set as 5 (like your snapshot clearly shows), the next time you display volvo850diag.html with a new instance of IE, the Realterm Terminal pane should display the yellow text showing successful ELM327 commands (rather than being a blank screen).

If it were me I'd also make sure that all instances of IE had been exited, before displaying volvo850diag.html with IE (just in case IE is intelligent enough to know about the other instances and shares some component amongst them which inhibits the reevaluation of any newly set environment variables).

2. If you go to Realterm's Port tab soon after Realterm starts and the yellow text appears, don't be confused by the fact that the Realterm Port tab's lower right corner still displays the Port as Closed after that initial successful ELM327 communication driven by volvo850diag -- evidenced by the yellow text in Realterm's Terminal pane with obviously successful ELM327 commands. I have no idea why Realterm doesn't update the Port tab's Port status when the opening of the port is driven by ActiveX instead of interactions on the Port tab. But to me that's a minor flaw. It doesn't concern me much.

3. Both items 1 and 2 behaviors are not intuitively obvious. Both of them confused me initially.

esl_97_850_T5