Need help. MPGuino GPH jumps around.

[theforce]

I built an MPGuino and I'm having some problems with it.

I got everything working fine except that when I put it in the car the GPH is all over the place. It will bounce to 0.07 to 10.00 or more. Any ideas on what would cause this?

[dcb]

loose/shorting connection? Wrong connection/circuit? You tried to install it on a lear jet?

what value resistors did you use next to the zeners? And did you use 5 volt zeners?

[theforce]

All secure connections. All hooked into the correct location. Tried Honda Civic VX ( intended car ) and my Honda Insight.

I tried both 50k and 100k resistors. Both zener diodes are 5.1v.

I've also even changed out the Arduino board but get the same result.

[dcb]

Dunno, there is a 94 VX that someone added to the table of car settings, so the circuit and program as described should work. What cpu do you have on your duino?

MPGuino - EcoModder

[theforce]

Using an Arduino Duemilanove (clone) which uses the ATmega328 running at 16mhz.

[dcb]

what version of arduino? What source code (link)? What schematic (link)?

[theforce]

Using version 0022 of the software. Tried using the stock 0.75 version of the MPGuino source that is on the wiki and I also intergrated the save data code in a seprate source. Both give same results. I'm using the arduino schmatic that is on the wiki.

[theforce]

I'll try to post the serial data later tonight. I have not looked at it when in the car. Maybe it will tell us somthing.

[dcb]

you might try the cpp file instead, and without making any modifications first.
http://opengauge.googlecode.com/svn/...no/mpguino.cpp I only tried it once from arduino. You might also try version 11 of arduino like the pde file says.

[theforce]

With the cpp file wont I have to program it with the ISP header? Never done that before. I think I have the nessary equipment to make the cable if needed.

I'll try version 11. I thought it was just so it could fit on the atmega128. I'll try anyway.