OBD MPGuino gauge - Page 8 - Fuel Economy, Hypermiling, EcoModding News and Forum

cmags · 07-09-2008, 01:21 AM

^^ Yes, it can be changed, but will still require a little re-wiring. As both dcb and I mentioned, the LCD4Bit library is coded such that the 4 arduino pins for the LCD *must be consecutive* and the way dcb wired the 'duino for his own code was not consecutive. Didn't get a chance to test it tonight, but I will load up the code and see what's up, hopefully tomorrow.

Magister · 07-09-2008, 10:10 AM

Thanks guys for testing the LCD thing, as the 4bits library is already written I wanted to use it, I don't know if it's better to adapt the .h or use the lib dcb wrote?

For the MAP thing yeah I put a comment in the code for the moment

dcb · 07-09-2008, 10:32 AM

It depends on your goals. If you want to appeal to the largest audience then code that is just cut and paste is the way to go. This was part of the phiolosophy behind mpguino, to make it as simple and straight forward as possible for the end user so the most people will benefit from it. You have to remove yourself from what you already know about "how easy this stuff is" in order to see that other folks will be stretching things to get this up and running. It is easy enough once you know all the technical details, but we are just trying to get instrumentation in as many cars as possible with as few obsticals as possible.

It would be cool if you could reuse the mpguino pinout and we would have a "standard computer" between obduino and mpguino that folks could write cut and paste applications for (without needing a degree in arduino). Three buttons, and a display and a processor at known pinouts simplifies that more than you may realize, and at least WE won't have an arbitrary hardware branch because of a lazy LCD library. Is anyone willing to fix the 4 bit library?

The pin selections for the mpguino were not arbitrary. They were carefully chosen. You guys have to decide what is best for the project so I won't keep harping on this, but it is something of a compromise between easy on developers and easy on the end users.

Here is what magister has put together for the wiring. I suggest that you agree on the hardware layout and decide on who the target audience is and how much code futzing they can manage to adopt to arbitrary wiring changes.

Magister · 07-09-2008, 10:34 AM

ok I'll change the OBDuino code to remove the 4bits lib and re-use your code!

EDIT: done, the code is in the trunk.

jmonroe: I installed a full cygwin environment on my windows box and use svn in bash to commit/update. There is a "Tortoise" GUI but I never used it.

dcb · 07-09-2008, 11:33 AM

Ok, that's fine but some discussion on it is ok too. There is no car that the obduino works with that the mpguino wouldn't also work with, so it may be that the goals for obduino are a little different. And the mpguino code is a moving target (which is why libraries are nice). So it could be fruitful to have some discussion about what you want to accomplish with obduino.

Magister · 07-09-2008, 11:54 AM

True

With the OBDuino I want to display information, preferably 4, user chosen, like for instance fuel consumption, vss, rpm, load, etc. in the 4 LCD corners. 16x2 is a little bit small and a 20x2 could have been better however.

Also a nice thing is MIL code retrieving and/or clearing, I am working on it a little bit, it's not complicated.

Having the same libraries as you for LCD and even for buttons management and for parameters management is a +, we should put all the common code in the same place like in the end of our sketch or in a separate source file. The end user should only have to do one (or more?) copy/paste then compile and upload to his board.

Having the same hardware layer (at least for the LCD) than the mpguino is definitively a + too in case someone want to make a *duino/lcd/buttons PCB all-in-one board in Eagle. I use pin D2 and D3 and you use pin D2, D3 and A0, everything else is common. Then the communication interface (VSS+inj or ISO) is another little PCB extension.

There is still a lot of work to do for parameters load/save and menu navigation, there is no menu anyway for the moment lol

Yoshi · 07-09-2008, 12:56 PM

Quote:

Originally Posted by dcb

Is anyone willing to fix the 4 bit library?

Posted my proposal to the LCD thread.
http://ecomodder.com/forum/showthrea...html#post42364

Yoshi

tom43571 · 07-09-2008, 07:43 PM

I have it fully assembled and ready to test. Unfortunetly I just found out that the only car I have that is ISO uses a MAP sensor and will not work with this code. If anyone wants to add in the code to read a MAP, I will gladly try it out.