Any interest in developing an open source fuel economy gauge/computer?

[mpgx2]

Originally Posted by dkostas

I have a proposal for making almost perfect solution for fuel economy gauge/computer.
The MPGuino kit is a very cheep and nice device providing just enough info for monitoring things related to fuel consumption, especially for the older generation vehicles which do not have OBDII. However, to put a small LCD on your vehicle is not an easy task if you want to keep a good look of your car's interior and options for keeping history or uploading data to the web are also very limited if possible at all at the moment. The best monitor I think would be to transmit the real-time data to the more serious devices such as PC, PDA, Smartphone, etc. The most comfortable way would be to modify the current design so that we could hook a simple serial Bluetooth module to MPGuino board and use it instead of USB. Most of todays PCs, PDAs, Smartphones etc. has Bluetooth as de facto standard and the communication is as simple as with USB connection. Since MPGuino already sends processed data via serial link twice a second, we do not need to write complicated software. It is only the simple terminal needed to read Bluetooth serial port on PC, PDA etc. and show the info on the screen. I think once this step of integrating Bluetooth is made, the monitor software can be created practically in minutes on any platform, be it Palm, iPhone, Symbian, Windows Mobile, Windows, Linux, MacOS, etc.

If Bluetooth module integration is not an easy solution, then maybe it is possible to use Arduino BT version for MPGuino, however, the price difference makes it not so afordable at the moment.

I totally agree and have been giving this some thought.

What I have been working on is an idea to put a message-bus on to
the arduino. Much like LIN or the CAN bus. Ideally, what you want is
a serial bus that you can transmit whatever data you want over.

(Just like what you get in a modern car, ie a CAN or LIN bus)

Lets pretend we don't have a new car, or that all we have
is an arduino, a pc with a serial port.

I've just got the bus implementation for TCP/IP going on the
PC. It's sort of a simplistic ascii only data bus based on a
chat server.

So, the idea is that we can transmit data on the serial line
like this:

rpm: 2500
water-temp: 160
throttle-position: 10

That way, we can send data easily over bluetooth or
LIN or CAN, serial-port or whatever bus/transport is available.

http://www.bitbucket.org/djlyon/mpgx...aster-tcpip.py

[dcb]

do you have any idea how much an arduino BT costs? Hint, its $150.

I actually put a serial<->tcp proxy together, back in 2008 (like that post you responded to), also:
Arduino playground - JavaProxy

and used that to communicate with an atmega from python/web pages/whatever. But tcp and bluetooth is all pretty much overkill for a car when you can just read the serial port with a couple feet of wire.

Also, the guino is already transmitting injector/distance data. the obduino may be sending even more data (no lack of data on the actual obd and can busses either).

I think writing a can bus to sort-of-can-like protocol over tcp over bluetooth based "mpg gauge", for $200, is kinda rube goldbergish at best. Keep us posted

[mpgx2]

Hi dcb,

Nice Javaproxy concept... :-)

Well bluetooth keys are as little as $2.95 so the price on
the bluetooth arduino only has space for downward motion.

In a way you are right about arduino and tcp/ip being
overkill. Sure it is only a few feet.

But when I looked at your Java logger, i thought how
much nicer it could be if every device was on it's own
port and could send data in.

Then, I sortof discovered that is what the LIN and
CAN bus do anyway.

So to cut a long story short, it seems to make sense
to have some sort of serial-bus support in any
project that does arduino.

I am told that if you can read the CAN or LIN bus then
a lot of the data that mpguino needs is there.

My friend in Germany also says that you can poke
your own commands on the CAN/LIN bus to do
DIY cruise control and so forth.

So I think that stuff like that could be sort of interesting
/worthwhile.