Enhancements to MPGuino code -- bargraph display, etc. - Page 2 - Fuel Economy, Hypermiling, EcoModding News and Forum

skelly · 07-22-2009, 12:19 AM

Quote:

Originally Posted by arlo

skelly,
Where have you posted this code? I really wanted to check out distance to empty. I made a function for it, but it takes up too much memory and won't fit.
Thanks

Hi arlo,

I have not figured out a place to put the code yet. Any ideas?

I did not try

Here is essentially the code for DTE. You will need to add a #define somewhere:

Code:

#define DTE_CFG                    1  /* 0=Off 1=On        */

My call to "doDisplayBigDTE" here:

Code:

pFunc displayFuncs[] ={
   doDisplayCustom,
   doDisplayInstantCurrent,
   doDisplayInstantTank,
   doDisplayBigInstant,
   doDisplayBigCurrent,
   doDisplayBigTank,
   doDisplayCurrentTripData,
   doDisplayTankTripData,
   doDisplayEOCIdleData,
   doDisplaySystemInfo,
#if (BARGRAPH_DISPLAY_CFG == 1)
   doDisplayBigPeriodic,
   doDisplayBarGraph,
#endif
#if (DTE_CFG == 1)
   doDisplayBigDTE,
#endif
};

Also you need to add a label to it:

Code:

   displayFuncNames[x++]=  PSTR("Custom  ");
   displayFuncNames[x++]=  PSTR("Instant/Current ");
   displayFuncNames[x++]=  PSTR("Instant/Tank ");
   displayFuncNames[x++]=  PSTR("BIG Instant ");
   displayFuncNames[x++]=  PSTR("BIG Current ");
   displayFuncNames[x++]=  PSTR("BIG Tank ");
   displayFuncNames[x++]=  PSTR("Current ");
   displayFuncNames[x++]=  PSTR("Tank ");
   displayFuncNames[x++]=  PSTR("EOC mi/Idle gal ");
   displayFuncNames[x++]=  PSTR("CPU Monitor ");
#if (BARGRAPH_DISPLAY_CFG == 1)
   displayFuncNames[x++]=  PSTR("BIG Periodic ");
   displayFuncNames[x++]=  PSTR("Bargraph ");
#endif
#if (DTE_CFG == 1)
   displayFuncNames[x++]=  PSTR("BIG DTE ");
#endif

And here is the function. The 'safety factor' there is if you want to subtract a gallon or so to ensure that even when DTE says zero, you still maybe have a gallon left.

Code:

#if (DTE_CFG == 1)
void doDisplayBigDTE(void) {
   unsigned long dte;
   signed long gals_remaining;
   /* TODO: user configurable safety factor see minus zero below */
   gals_remaining = (parms[tankSizeIdx] - tank.gallons()) - 0;
   gals_remaining = MAX(gals_remaining, 0);
   dte = gals_remaining * (tank.mpg()/100);
   dte /= 10; /* divide by 10 here to avoid precision loss */
   /* dividing a signed long by 10 for some reason adds 100 bytes to program size?
    * otherwise I would've divided gals by 10 earlier! */
   bigNum(dte, "DIST", "TO E");
}

You need this supporting macro "MAX":

Code:

#define MAX(value2, value1)\
    (((value1)>=(value2)) ? (value1) : (value2))

cjm · 07-22-2009, 01:22 AM

Not sure if this is the right thread to ask this question, but I haven't seen a more appropriate place. I'm interested in logging data to a PC so that long trips can be profiled and routes analyzed. PC logging would be helpful in coast down tests too. Would adding a serial output to the MPGuino require substantial coding? or is it just a matter of finding someone who is familiar with these sorts of electronics to add that physical interface? Do you know of anyone who's done this or is working on it? Thanks.

skelly · 07-22-2009, 10:37 AM

Quote:

Would adding a serial output to the MPGuino require substantial coding? or is it just a matter of finding someone who is familiar with these sorts of electronics to add that physical interface?

I have the 'spiffie' hardware that has a USB plug on it. dcb's code (at least version 0.75) already has a serial output enabled and active. If you plug the USB into your PC, the PC recognizes it as a serial port, and you should see economy, speed, etc. being spit out.

Does the prebuilt unit have a USB plug on it? If so, and you are running at least version 0.75 of the MPGuino software, what you are asking for is already there.

cjm · 07-22-2009, 11:04 AM

Thanks for the response, skelly. I have not yet purchased the prebuilt unit -- just shopping right now. If it has the USB plug you describe, my shopping will be done. I can't really tell from the picture on the web site. Can anyone here confirm that there is a USB plug on the prebuilt? Thanks.

dcb · 07-25-2009, 11:39 AM

Nope, the usb was an addition on the spiffed kit (arduino legacy), was never part of the original mpguino except when built from an arduino or clone, though the data is still being transmitted on pin 3 of the cpu for the adventurous sorts (wire in a max232 or bluetooth or ft232rl, or just do straight uart to a large display or ???).

Fhajad · 07-26-2009, 02:12 PM

So pretty much all you did was just swap out the chip and put in a higher capacity one? Did you have to reflash it at all or na?

hu_man · 07-27-2009, 11:50 AM

Skelly you are onto something here. I am planning a 328 upgrade to make room for more programming. I would also like to see your code as I have some ideas of my own and I like your gals to empty idea a lot. I can not trust my fuel gauge so I am always filling up to soon. This would help. I do use the gal used but a direct screen would be nice.
Thanks for your post
Hugh

JohnNeiferd · 08-04-2009, 09:46 PM

A few features I think would be cool are 1) and rpm feature based on injector pulses per minute (as already suggested by someone else). And 2) a 1/4 mile time set up so a screen would display a timer that starts when the vehicle speed increases from 0, and stops when the odometer reaches 0.25. It would also display the speed you were at when the timer stopped. You're 1/4 mile time and top speed could be used to get a rough estimate of horsepower from calculators online. It'd be interesting to see how our fuel economy mods change the horsepower output of the engine.