MPGuino release one workspace

[MilesPerTank]

Ok.

Ill update the vss constant to the above posted 4100 and that should take care of my speedo.

[dcb]

Yah, or 4104, close enough, let me know if that works ( it should).

Edit, I must have fixed the double vss issue

Edit #2, I can't say for sure what is going on there just yet, I have 8208 in a geo and it looks pretty solid. Let me know where you land with an accurate VSS.

[dcb]

Update, fixing hanging at 71.5 minutes issue in progress (need to update signal generator too).

[diesel_john]

Originally Posted by dcb

Well I think the 95-98 saturns are afflicted. dieselJohns truck might be, but he put a check valve in the vacuum system and is counting on the 02 sensor to correct maybe? Maybe john can go into detail about the side effects of the check valve, if any.

I am taking off all mods. to the fuel pressure regulator. I was wrong in my hypothesis, the injector based mileage computer works just fine with the stock fuel pressure.

Pics on MAP sensor operation.

[dcb]

Thanks for the update John.



71 minute update: I've updated the code in post 1 and am testing the 70 minute issue on the bench now. It takes a while to debug problems that take 70 minutes to reproduce

update #2, It is still running after 81 minutes so I think we are clear. I'll leave it running (need more guinos).

[dcb]

Tank Raw Data
IJ3440.0uS284920
IC405740VC147544 //display format may overflow, but model is intact.

Tank display
Time 650:57 minutes 78120 loops
Miles 214.86
Gallons 3.79
MPG 56.74
MPH 8.81

Instant Raw Data
IJ000.00uS044064
IC018.00VC027.00 (toggles between 27 and 28)

Instant display
MPH ~20
MPG 41.67


so @ 651 minutes, we have made 78120 1/2 second loops.

Fuel check:
the injector was open for ~ 44064 microseconds per loop
so that is 3442279680 microseconds of open injector time
and we have 3440 seconds displayed in IJ for the trip, close enough!!

Injector count: 78120 * 18 = 1406160, displayed 405740 (assuming leading one isn't displayed), again, close enough. We don't care about injector count except for RPM calculations which we havent tackled yet.

Distance check: 78120 * 27.5 = 2148300, displayed 147544 (assuming leading 2 isn't displayed), again close enough for a quick sanity check like this.

So the data collection logic and the data model appears to be reasonably sound, no? I think the remaining display glitches are a display problem. Note, the tank mph has started creeping up again while typing this.

[dcb]

I don't know if it is a mph clue, but I checked at 1121 minutes and the trip mph was at 0.63 and climbing. 370 miles registered. Everything looks stable (free mem, cpu usage, mpg readings, etc). Signal generator is still generating fine too.

next display glitch: @ 1400 minutes, noticed tank mpg was 4.06, miles 33.21, gal 8.16

[AndrewJ]

Just thought I'd post up to say that my LCD died...

I'll look into the situation tomorrow, luckily I just recived a new freeduino and LCD (to make a second MPGuino) in the mail, so I have another LCD to mess with.

Any suggestions for troubleshooting the LCD? I think it's just the LCD because the 'duino's LED's blink normally when powered up, but the display is blank with the backlight off.

[dcb]

Originally Posted by AndrewJ

Just thought I'd post up to say that my LCD died...

I'll look into the situation tomorrow, luckily I just recived a new freeduino and LCD (to make a second MPGuino) in the mail, so I have another LCD to mess with.

Any suggestions for troubleshooting the LCD? I think it's just the LCD because the 'duino's LED's blink normally when powered up, but the display is blank with the backlight off.

Can you jumper power to the led and see if it still lights up? It could be a common ground, or common power thing, any points in your system that would be a common point of failure for the LCD and backlight? Have you looked at it from all angles in case the contrast got wonked somehow?

Also, are you disconnecting the power or hitting the reset button? The LCD doesn't currently like the reset button and prefers to initialize from a power up (especially annoying in development mode).

Last thing I can think of: have you tried reprogramming the guino? Sometimes the atmel chips gets confused during a brownout and needs to be reprogrammed, occasionally they even need a new bootloader (PITA) so be real deliberate with the power hookup.

If not, see if the new chip works in the old guino. If it does and the old chip doesn't then you can send the old chip to me and I'll see if I can do an autopsy on it and find the cause of death.

Let me know what you find out.

[cmags]

Hey, when powering the 'guino on the bench, what spec power supplies are you guys using? I have a 12v, 200mA supply that happened to fit well and used that for the basic blink tests and such to ensure the 'duino was working, but when I hook up the LCD, blink doesn't even run. So, either my LCD is toasted (its from the parts bin so its possible), or the power supply just doesn't have enough oomph.