Author Topic: Bluetooth straight to FBUS, bypassing MAX232  (Read 8460 times)

Offline BiSiE

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Bluetooth straight to FBUS, bypassing MAX232
« on: July 08, 2015, 12:14:06 am »
Hi all,

Just wondering if anyone has any input on my mod.

Goal: Add bluetooth module to use with Android VEMS app (possibly internal, with external antennae?)

Details:
VEMS 3.3
Bluetooth module: 1132-SPF by sparkfun
(http://www.canadarobotix.com/bluetooth/12576-sparkfun-bluetooth-mate-silver)
Module Voltage range: 3-6v

Problem: the module does not speak RS232, rather TLT

I'm planning tapping directly into the FBUS using method described in this writeup:
http://www.vems.hu/wiki/index.php?page=GenBoard%2FManual%2FCommHardware

I was thinking of using the 5volt power from VEMS to drive the module, but I can't find any documentation that indicates if AVR (pin2 and 3?) can take the 5volts coming out of the bluetooth module?

According to the spec of the bluetooth module, it will output what ever voltage is supplied to it (between 3-6v).

Any suggestions/comments very much appreciated!

p.s. the reason why i don't just get an rs232-bluetooth adapter and call it a day is because i already bought the 1132-spf, plus I like a challenge ;)
VW Jetta 1986 Coupe, VR6, 270 cam, 11.5:1, MSD coils, factory sensors and IAC
VEMS 3.3, custom harness

Offline paul_f

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Re: Bluetooth straight to FBUS, bypassing MAX232
« Reply #1 on: July 08, 2015, 07:19:11 am »
I used a similar device, but used a MAX232 to interface into the RS232

Offline mads b (dk)

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Vw beach buggy 1.6 VNT turbo, Vems 3.1 no. 57

Offline BiSiE

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Re: Bluetooth straight to FBUS, bypassing MAX232
« Reply #3 on: July 08, 2015, 04:48:18 pm »
http://www.vemssupport.com/forum/index.php/topic,1740.165.html

Nice! thank you.

So just to clarify, you were able to have both options available together (one at-a-time):
-Serial RS232 for logging/tuning
-Bluetooth adapter, tapped before the MAX232 chip in TX only mode, for Android app (using 5v power tapped from the main board)

Questions:
Did you ever endup having success using bluetooth for tuning (with RX connected)?

Thanks again
VW Jetta 1986 Coupe, VR6, 270 cam, 11.5:1, MSD coils, factory sensors and IAC
VEMS 3.3, custom harness

Offline BiSiE

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Re: Bluetooth straight to FBUS, bypassing MAX232
« Reply #4 on: July 08, 2015, 04:52:11 pm »
I used a similar device, but used a MAX232 to interface into the RS232

Thank you!

I have considered this option, it would be easy to implement as a swappable plug, using something like:
https://www.sparkfun.com/products/449
and then the bluetooth module.

However it just doesn't seem "clean" to me having the max232 chip on both ends. plus I would have to order and wait for more hardware :)

It is a usable solution nevertheless.
VW Jetta 1986 Coupe, VR6, 270 cam, 11.5:1, MSD coils, factory sensors and IAC
VEMS 3.3, custom harness

Offline mads b (dk)

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Re: Bluetooth straight to FBUS, bypassing MAX232
« Reply #5 on: July 08, 2015, 05:29:06 pm »
I use bluetooth for both android og pc tuning software .... works pefectly
« Last Edit: July 08, 2015, 06:44:06 pm by mads b (dk) »
Vw beach buggy 1.6 VNT turbo, Vems 3.1 no. 57