OBD MPGuino gauge

[eimix]

#ifdef UseOutsideTemperatureSensor
  #define OutsideTemperaturePin 15 // Inside temperature sensor, on analog 1
#endif

#ifdef UseInsideTemperatureSensor
  #define InsideTemperaturePin 16 // Inside temperature sensor, on analog 2
#endif

And I connected it

 +5V ---- 2kOhm resistor -----|------ KTY81 ------ GND
                              |
                              |
                              |
                          PIN 16 or 15

[crysty7]

Sorry, I'm a dummy ...

I don't find pin 15 or 16 om Arduino board .

[eimix]

#ifdef UseOutsideTemperatureSensor
  #define OutsideTemperaturePin 15 // Inside temperature sensor, on analog 1
#endif

#ifdef UseInsideTemperatureSensor
  #define InsideTemperaturePin 16 // Inside temperature sensor, on analog 2
#endif

On board it is analog pins 1 & 2, but in Arduino software it is 15 & 16, same pins, but different numbers. I do not know why.

[ecoxantia]

This is very very cool.

Has anyone tried this on a VW group TDI? I'd like to know what protocol it uses. Specifically I have a 2006 1.4TDI Skoda.

thanks!

[eimix]

according to List of Confirmed Vehicle OBD-II Scan Tool Protocols or OBDII Trouble Code Reader
ISO protocols are until 2003, and from 2007 only CAN protocol is used.

Hopefully somebody has this exact model and can confirm if it is ISO compatible.

[Magister]

Q I received by email
--------------------

Hi OBduino team,

I have build the OBDuino ISO, and it works as it should :-)

Today however I've made an observation that I can't figure out. I was watch the PID's INST CONS and Out Cons. On the highway - the Out Cons was showing 5,80 L/100 and the INST CONS was showing 4,8-4,9 L/100. I noticed that the Out Cons was increasing, even though that the Inst Cons all the time was lower than Out Cons. How can that be? - I would have thought that as long as the inst cons is lower than out cons, the out cons will decrease.

I have a couple of ideas to the OBDuino:

The BigNum display with AVG and INST cons - is made as two bargraphs instead of numeric. It would be easier/faster to see if you are increasing/decreasing the inst cons compared to AVG cons. It could be made for instance, that the lower display row, is lit up according to the AVG cons, and the upper display row a single character block would represent the INST cons.

As many users of the OBDuino (and other Car-computers) have noticed, the INST cons isn't very usefull because of the sensitivity. It changes very rapidly due to changes ins terrain, wind and so on. What I have been thinking of was that it would bed nice to have an AVG_CONS_10 for the last 10 seconds (or whatever would be suitable), and this should be done continuosly. Simply by using the INST CONS for the last 10 seconds, finding the average, and then do this repeatedly for every update cycle. I think this would be at good compromise between the INST CONS and the OUT CONS.

By the way - is there any software-updates planned for the OBDuino - ISO?

Kind regards
Torben

[eimix]

Checked code for described behaviour, but no problems found.

It could be becouse of modified constants

/**************************/
/* GASOLINE ENGINE CONFIG */
/**************************/
// [CONFIRMED] For gas car use 3355 (1/14.7/730*3600)*10000
#define GasConst 3355 
#define GasMafConst 107310 // 14.7*730*10

One is used for instant calculations, other one - for rest of calculations.
And if only one of them is modified - other has to be changed too.
(to check if correct values are set - multiplication of both of them should be
3355*107310 = 360025050 ~= 3600 * 100000.

Also it could be "config" dependent - need value of "Fuel %", or is it default one?
params.fuel_adjust is not used in instant consumption calculation.
if this is the problem - it should be added in "fast repair" list.
-------------------------------------------

Idea for improving OBDuino - nice, some day, someone should add it to list

[Magister]

I think I can fix the "adjust" not being used in instant cons and also add a "smooth" array to take the last 10 value or something like this, give me a couple of days.

[Magister]

I made change for a new version (187) with instant cons smoothing, and it takes into account the adjustment of speed and fuel.

Can someone try it?

[Magister]

received by email
-----------------


I have tested the new release today. It seems to work okay, but the smoothing function seems to have some side-effects:

When the car is started but not moving the INST CONS is shown as L/100 and not as L/h as before the update. I’m not sure if the numbers are okay – but the units are not.
When the is moving and I push the clutch so the engine is in neutral, the INST CONS is showing 0.00 for some seconds and the it shows the idle consuming.

The smoothing seems to be working well, especially at constant speed (for instance at the highway). There it seems to be easier to read because the numbers don’t change all the time.

I’ll return to you if I observe other things – during the next week or so.

I’ve got a couple of new ideas:
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 J if you could choose among all the numeric PID’s to be shown at the BigNum screen, for instance Speed or RPM – or whatever.