OBD MPGuino gauge

[gone.s2]

Cool, thanks for checking.

Originally Posted by eimix

Tested in my car (gas + lpg) but engine load PID04 does not drop to zero.
At low revs 1% engine load, downhill with DFCO it shows 3% engine load.

So PID04 does not look promising for DFCO detection.

[eimix]

Is there any more ideas and feature requests?
i'm in mood to develope something

current feature request list in .pde file (SD logging etc) does not look needful. or are they?

was thinking about graphic LCD ~128x128pixels monochrome or color, but did not find any cheap (~10$) and acceptable, most of them with "breakboard" are ~20-30$

[eimix]

In config menu - some times buttons are not responding as they should or delay ir slow.

In ISO mode it is because in accu_trip() minimum 3 pids are readed and we get 3x55ms=165ms + some more gap in ACCU_WAIT frame then buttons are inactive.
Need to minimize PID read delay or increase ACCU_WAIT for better config menu response.

I will try:
#define ISORequestDelay 35
#define ACCU_WAIT 2000 // or more

Commonly car is not moving in config menu so there is no need to accumulate data so often, right?

For a while i do not see any other problem in config menu button response issue.

[TurboTorben]

Hi Eimix,

I've earlier presented these suggetions (by mail to Magister):

It would be nice if you could choose the BigNum font as an option in the config menu – so you didn’t have to reload the code just because you want to change the BigNum font. It would also be very nice if you could choose among all the numeric PID’s to be shown at the BigNum screen, for instance Speed or RPM – or whatever.
Last - in would be nice if you could configure - wether you will have your consumption presented as L/100 or km/l.

I would be very interested if you start a graphics display development. I've been thinking at little about this myself - and how data should be presented. At the moment I think the best presentation (easiest to read when driving), would be analog speedometer style, eventually with two "hands" (one for instant and one for average - then it would be easy to see wether or not you are doing better than average or not)

Hope that you are inspired to develop some of this...

Kind regards

TT

[gone.s2]

Originally Posted by eimix

Is there any more ideas and feature requests?
i'm in mood to develope something

Not a feature request, but if possible could you test ISO reinit / ecu polling with 187 to verify that I'm not losing my mind. i.e. build with all the default settings for ISO9141. If I don't disable #define do_ISO_Reinit and #define skip_ISO_Init mine never passes iso_init() and I'm not seeing the reason through the cloud of conditional compilation blocks.

One suggestion I would make (if it's not already being done and I just overlooked it) is mandatory caching of the RPM pid in each tick of loop() instead of casting it into a boolean value. You're already polling the ECU for it, why not store it and save comm bandwidth for other pids. VSS is another candidate for mandatory caching. EDIT: I found the PID Caching, think it could be improved to help with menu responsiveness.

I would also echo TurboTorben on one aspect of the bignum screens. Make them both user configurable the same way the regular font screens are. Also, it appears that the decimal point placement on the first bigNum is off by one (possibly only when using US units).

Lastly, allow for (read: make default) the removal of the security screen when do_ISO_Reinit is enabled. It's unclear what it accomplishes functionally, but it seems a bit of a waste of precious flash memory.

EDIT: Another possible bug, and another feature request:

save_params_and_display() seems to be getting executed unecessarily. This may be specific to my application, but I'm not seeing the reason why. EDIT: NEVERMIND found the cause, seems like it might be pid caching.

Request: Power Management
Has SLEEP_MODE_IDLE ever been attempted? Disable ADC? Just thinking out loud. 50ma won't kill a healthy battery too quickly, but if not kept on a battery maintainer it won't take long before that healthy battery is sulfated beyond recovery.

[gone.s2]

Originally Posted by Magister

I tried a lot of things to have a more accurate value, using wideband O2 sensor value, lambda value, etc.

After thousands of logs, I saw that the correction using this PIDs was not really worth it. About all the corrections were between 0.97 and 1.03, so adding time to ask for these PID (some car do not have wideband O2 sensor anyway) was a little bit useless. Especially that at the end, the average was about right.

This pid is apparently quite different for diesel. I originally overlooked it, but from: About PID Calculated Load Value that eimix referenced previously:

Compression ignition engines (diesels) shall support this PID using fuel flow in place of airflow for the above calculations.

So it appears to be the right avenue for my application. I will report back after I've been able to test. Unfortunately I'm struggling with some issues related to ecu polling / reinit which have hindered my progress towards my intended goal. It's been a while since I've dabbled in avr_gcc, and this latest revisit has rewarded me with several new gray hairs.

What I've probably failed to mention about my ordeal with diesel application is that for whatever reason when I tested a default build no consumption was accumulated using the MAF configuration and the gasoline constants for stoich. I believe this is because the MAF for diesel is either not supported or returns erroneous values. Whatever the case, I've found numerous other references stating that CLV is the correct method for diesel. I don't want to open up a can of copyright worms by posting links, but simple google searches will get you there.

[eimix]

Originally Posted by TurboTorben

It would be nice if you could choose the BigNum font as an option in the config menu – so you didn’t have to reload the code just because you want to change the BigNum font.

changing big font without recompiling would cost ~400bytes + 200bytes for configuration,
fonts itself does not look worth it.
if you want to compare 2x2 alpha and beta fonts:


does any body knows what happens if additional variable is added to params?
how about saving/loading from eeprom? it will fail for first time with new version and some data will be lost

UPDATE: if useECUState is commented (disabled) and carAlarmScreen is enabled it looks wrong near

  #ifdef carAlarmScreen
    displayAlarmScreen();
  #else

just not jet figured out what is wrong and how to fix.
maybe somebody remembers how this should be?

[eimix]

Originally Posted by TurboTorben

It would also be very nice if you could choose among all the numeric PID’s to be shown at the BigNum screen, for instance Speed or RPM – or whatever.

It could be nice, but RPM is 4digit some others also 4 digits.
So this could be done only in screen #4 (first bignum), or in both, but additional info would be disabled in screen #5.

[TurboTorben]

Originally Posted by eimix

It could be nice, but RPM is 4digit some others also 4 digits.
So this could be done only in screen #4 (first bignum), or in both, but additional info would be disabled in screen #5.

In my opinion it isn't a big problem not to have additional info in the BigNum Screens. If someone want to see more than one PID, this should be done in screen 1-3. I think BigNum screens should be used for improving readability of the most interesting PID (whatever this is)- and the readability isn't improved with the additional info using small font.

[gone.s2]

Originally Posted by TurboTorben

If someone want to see more than one PID, this should be done in screen 1-3. I think BigNum screens should be used for improving readability of the most interesting PID (whatever this is)- and the readability isn't improved with the additional info using small font.

Personally I think it would be most useful to only have one bignum screen, and let the user choose one of a limited number of PIDs for the big font, and possibly two others for the right side of the display in normal font. For hypermiling this would give the most critical info in big font, and then the user could pick two other pids they might care to see less frequently when they have time to focus on the smaller fonts. Personally I'd like to see load and vss.

I haven't investigated whether or not there is be room for this however - I'm using a 2x20 lcd so I didn't really consider 2x16 lcds with my previous comment.