Bluetooth Connectivity

jestes · Post by **jestes** » Sun Jan 20, 2013 10:03 pm

I know this has been brought up before, but every post I've seen talks about how you could connect an external serial to bluetooth device to the RJ-45 port outside the box. What about cracking it open and hardwiring something like this to the inside of the box? It would be much cheaper and you don't have to mount a seperate device. I'm not an EE, so I'm just dreaming here... Any thoughts?

http://www.ebay.com/itm/Wireless-Serial ... 5650afe3a9

Post by **brentp** » Tue Jan 22, 2013 5:21 am

Hi- Yes, we've actually been looking at exactly those modules. We're making a Blluetooth adapter using this module for Race capture, it would be pretty easy to adapt to Megajolt as well.

DannyP · Post by **DannyP** » Sun Jan 27, 2013 3:33 pm

That looks really promising. I guess I will have to learn more about wireless peotocols.....

Post by **brentp** » Sun Jan 27, 2013 9:45 pm

There's not much too it- once they're setup you treat it like a serial port!

bobclevenger · Post by **bobclevenger** » Mon Dec 23, 2013 3:59 am

This looks very interesting. It would (obviously) eliminate the external cable from the MJLJ box to the computer. Combine this with having the configurator software on a BT-enabled device (such as an Android tablet or a Windows Phone) and making quick changes to the advance curve would be easy, neat, and quick. I was thinking of trying a serial (RS-232) to BT adapter, but given the huge number of RS-232 to USB adapters that do not work with the MJLJ system I thought better about investing in an unproven RS-232 to BT adapter.

jestes · Post by **jestes** » Mon Dec 23, 2013 4:16 am

I've been using this system in my car for about 5 months now with great success. My only complaint is the range is not very good. However, Brent has suggested that I take the metal ends off the MegaJolt box to see if that helps. If it does, I'll make a set of ends out of a more RF friendly material. If you watch the startup video in my blog, you can see the tablet with the gauges. At this point where the video was made there was a bug so the gauges were way off, but that has been fixed.
http://57bugbuild.blogspot.com/

jestes · Post by **jestes** » Mon Dec 23, 2013 4:17 am

BTW - Right now, I'm actually using a Bluetooth enabled laptop with Either my Windows based software or Brent's, depending on what I'm doing with the MJ at the time. My app does not support data logging, so I use his for that.

Alex B · Post by **Alex B** » Mon Dec 23, 2013 9:06 am

This is cool, I just bought a similar Bluetooth module to modernize communications so I am very happy getting confimed this way that it should work

.

Alex

bobclevenger · Post by **bobclevenger** » Mon Dec 23, 2013 9:04 pm

Cool...
It's good to hear that these 4-wire RS-232 to BT adapters will work with the MJLJ hardware and software.

Any help on "which wires to connect where" would save me a fair bit of time and trouble.
as there are only 4! (24) combinations it shouldn't be a big problem ... unless one of the wrong connections damages something.

Thanks for any help.

Alex B · Post by **Alex B** » Mon Dec 23, 2013 10:38 pm

Picture from Jestes' blog:

.

My best guess is that the communication wires are down at the IC and voltage and ground come from the MAP-sensor. Jestes, is my guess correct?

Alex

bobclevenger · Post by **bobclevenger** » Mon Dec 23, 2013 10:46 pm

Thanks. This will be a big help.

bobclevenger · Post by **bobclevenger** » Thu Jan 02, 2014 1:48 am

OK, I just got my 4-wire serial to BT card and wired it up.
Of course I have problems, nothing ever works the first time around!

The BT itself seems to work. It powers up and is discovered by my PC. I finally got it paired, and Device Manager shows it on two com ports, com11 and com12. I am going to remove the device and reinstall it -- hopefully that will give me only one com port to use.

So far I have not been able to communicate with the configurator software on either com11 or com12. In fact the configurator program locks up and won't respond if I try to use it. I assume that I have BT communications but that the data from the MJLJ unit is not getting through to the BT link (or at least not getting through correctly). It is possible that I have the BT card wired wrong (TXD and RXD going to the wrong places on the MJLJ card

). The photo was helpful (after all I DID get the power connected correctly!) but it is not clear which wire goes where to pins 11 and 12 of that chip as they disappear behind the other two wires (power wires) and I do not know whether or not they cross over each other behind those wires. Is there an alternate location that can be used?

I do have a background as an electronc tech. but I have not worked with BT devices before. My knowledge is a bit dated, so feel free to explain things, as that will be helpful to others as well.

Thanks,

Alex B · Post by **Alex B** » Thu Jan 02, 2014 7:27 pm

Check this http://www.autosportlabs.net/MJLJ_V4_Operation_Guide and go to the "Connecting to the MJLJ" paragraph. Backtracing the connections from the RJ45 port to the chip should give the answer.

When you get things up and running please inform here how you did it; it will certainly be a big help for when I get my BT unit delivered in the course of this month

.

Alex

bobclevenger · Post by **bobclevenger** » Sat Jan 04, 2014 1:17 am

Status update.

I uninstalled and reinstalled the BT device. It is now on com11. The device on com13 is totally unrelated to this; it's just a driver that Panasonic installs from the factory.

So I connect things up and set the configurator software to com11. I launch the configurator software and, lo and behold, the computer says that a BT device is trying to connect! I enter the pairing code and the blinking red LED on the BT device changes to a solid red light. So far so good. Things seem to be communicating.

But then I get the following error code from the configurator software:

[begin error message]
Microsoft Visual C++ Runtime Library

[Big Red X]

This application has requested the Runtime to terminate it in an unusual way.
Please contact the application's support team for more information
<OK>
[end error message]

After I press the "OK" button I get another message which is as follows:

[begin message]
mjfjConfig.exe has stopped working.
A problem caused the program to stop working correctly. Windows will close the program and notify you if a solution is available.
<Close program>
[end message]

Yeah, like MS is going to find out anything about mjljConfigurator.exe!

So I am "contact[ing] the application's support team for more information."

BTW, I am running ver. 4.0.2 of the configurator software.

Any clues people?

bobclevenger · Post by **bobclevenger** » Sun Jan 05, 2014 8:18 am

No ideas at all?