Board logo

Bluetooth and MSquirt
Rob Lane - 6/3/06 at 10:43 AM

Has anyone tried the bluetooth implementation that Bruce used ?


I have the bt Socket adapter and it is connected up, trouble is it resets every few seconds, I get a correct read every 3rd or 4th packet.

I posted the question on the MSEFI forum but no luck so far.

I'm unable to see any parameters for the BT dongle on my laptop, so I could try a few settings to cure this. It appears to be a timing issue.


Rob Lane - 7/3/06 at 08:08 AM

Apparently it will work with V3 Ok but not V2.2 board

Something to do with 9600 baud timing.

Bruce did not make this clear on his write up !


MikeRJ - 7/3/06 at 10:02 AM

Sounds a bit dodgy to me, I thought V2.2 and V3 both used 9600 baud?

The V2.2 board is specificaly mentioned in http://www.megasquirt.info/com/bluetooth.html as possibly requiring a larger heatsink on the regulator.


Rob Lane - 7/3/06 at 12:27 PM

No, Bruce specifically used it on a V3 which outputs at 115k.
He only mentioned the V2.2 due to current requirements of the unit stressing the 5v regulator. Don't know why, it is rated at 1amp, unit has max 200mA and board has 200mA. I just think he was a bit conservative. Doesn't matter to me as I kept adapter on it's power supply anyway.

There's an interesting thread somewhere regarding WLAN radios in something called Hi Tech but I can't directly access this via forum. It must be within a category I haven't looked in.

Bruce mentions he used it on V3 board.

The Bluetooth serial adapter is working OK and connects to other devices faultlessly. It's the 2.2 version of MS that seems to have an odd output.

Timing seems to be the problem along with buffering, with no method of altering the parameters.

I'm not the only one who has discovered this.

[Edited on 7/3/06 by Rob Lane]


stevebubs - 7/3/06 at 02:48 PM

quote:
Originally posted by Rob Lane
No, Bruce specifically used it on a V3 which outputs at 115k.
He only mentioned the V2.2 due to current requirements of the unit stressing the 5v regulator. Don't know why, it is rated at 1amp, unit has max 200mA and board has 200mA. I just think he was a bit conservative. Doesn't matter to me as I kept adapter on it's power supply anyway.

There's an interesting thread somewhere regarding WLAN radios in something called Hi Tech but I can't directly access this via forum. It must be within a category I haven't looked in.

Bruce mentions he used it on V3 board.

The Bluetooth serial adapter is working OK and connects to other devices faultlessly. It's the 2.2 version of MS that seems to have an odd output.

Timing seems to be the problem along with buffering, with no method of altering the parameters.

I'm not the only one who has discovered this.

[Edited on 7/3/06 by Rob Lane]


V2.2 and V3 boards BOTH run at 9600.

They both also run at 19200 but ONLY with a MS-II ECU fitted.


MikeRJ - 7/3/06 at 06:06 PM

quote:
Originally posted by Rob Lane
No, Bruce specifically used it on a V3 which outputs at 115k.
He only mentioned the V2.2 due to current requirements of the unit stressing the 5v regulator. Don't know why, it is rated at 1amp, unit has max 200mA and board has 200mA. I just think he was a bit conservative.


The problem is one of power dissipation. With just the Megasquirt the regulator is dissipating:

(12-5) * 0.2 = 1.4 Watts

Add the Bluetooth module and this doubles to 2.4 Watts which will be starting to get quite toasty with minimal heatsinking.

With respect to the bluetooth problems, have you made all the required mods to the PCB as detailed in the link I posted?


Rob Lane - 7/3/06 at 06:40 PM

Yep, the link is where I first read of the BT Socket.

Note that if you load Bruces Socket BT config file on that link into the Socket BT config software and read it, Bruce has only set the BT config at 115k. It will still not work as the BT address is set at 00.00.00.00 and needs to be machine specific.

He has mailed to this effect, he did not try it at 9600 on a V2.2 or on a V3.
Unfortunately only if you read it carefully later you realise it's not tested with the V2.2 but assumed to do so.

Odd thing about the HiTech category on forum (could be my cache) is when I first load the MS EFi Index it's not there but when I visit another category and then return, it's there as a category.

Hmmm, maybe my link is old !

Point taken about the dissipation, I'm currently running it on bench off a lab supply set at 9v so it's not quite real world car supply.
Even at 12v on stim it doesn't get warm anyway, in the vehicle it would be different though.

[Edited on 7/3/06 by Rob Lane]


Rob Lane - 8/3/06 at 07:33 AM

Well, finally worked out where the Hi Tech forum is. It's there all the time but you need to be logged in to see it