t vago's MPGuino workspace thread

[t vago]

Ugh... did I actually type "L/100km"? That really should be "100km/L".

*headdesk*

[RedDevil]

Hi t vago,
100 km/l is not commonly used in metric fuel efficiency, just km/l or indeed l/100km.
Because then in most situations you'd get one or 2 digits before the decimal point.
In your example it would be 3.968 km/l or 25.2 l/100 km.

My car does about 3.968 l/100 km or 25.2 km/l btw

[josemapiro]

Originally Posted by t vago

Ugh... did I actually type "L/100km"? That really should be "100km/L".

*headdesk*

Ok,

Thank you
José Rodrigues

[josemapiro]

One question, when MPGuino goes to the clock display due to downtime, to click the button left or right goes to "Current Reset" is normal or is an error?

Thank you
José Rodrigues

[t vago]

Originally Posted by josemapiro

One question, when MPGuino goes to the clock display due to downtime, to click the button left or right goes to "Current Reset" is normal or is an error?

Thank you
José Rodrigues

Yah, it's normal. Anything, that wakes up the MPGuino, will reset the current trip data. It could be any single button press (or pressing any combination of buttons), or it could be a VSS pulse, or it could be a valid injector pulse.

I am wondering if this particular behavior should be changed - button presses, by themselves, would not necessarily reset the current trip if the MPGuino were to be woken up, but reading a VSS pulse or a valid injector pulse would still do so.

[josemapiro]

Originally Posted by t vago

Yah, it's normal. Anything, that wakes up the MPGuino, will reset the current trip data. It could be any single button press (or pressing any combination of buttons), or it could be a VSS pulse, or it could be a valid injector pulse.

I am wondering if this particular behavior should be changed - button presses, by themselves, would not necessarily reset the current trip if the MPGuino were to be woken up, but reading a VSS pulse or a valid injector pulse would still do so.

I think the best would be to reset by pressing the button for 1 second, because there is always the possibility to query all data from the last trip.
If the data is restarted due to the injector pulses, this means that we will make another trip, which is correct, the rest I believe it should only be done if we wish so.
Or create a possibility to choose in the setup menu.

Thank you
José Rodrigues

[Ardent]

Originally Posted by t vago

I am wondering if this particular behavior should be changed - button presses, by themselves, would not necessarily reset the current trip if the MPGuino were to be woken up, but reading a VSS pulse or a valid injector pulse would still do so.

I commented out the auto-reset behavior so that a current trip can span multiple stops.

I wouldn't be opposed to an auto trip reset #define, but I'm fine with how it is currently.

[AndrzejM]

I'm back home from my round trip. So I've drove for around 4300km testing new code. It works very good and stable, haven't noticed any issues. After first calibration it shows FE with amazing accuracy. Error on second tank was around 0.1%
Anyway I have some thoughts on new code.

One thing would be good - L/hr display or changing display from L/100km to L/hr during stops.
Graphs are nifty but not very useful.
I want to try to change code a bit to read engine's temp instead of pressures.

Overall I like new code very much. Great job t_vago! Thanks again

[t vago]

Originally Posted by josemapiro

...create a possibility to choose in the setup menu.

This is probably the route I will go with. I wanted to maintain the behavior of the original code, as best I could. Then again, I modified the dickens out of this same code, so there.

Look for an update in the next few days.

Originally Posted by Ardent

I wouldn't be opposed to an auto trip reset #define, but I'm fine with how it is currently.

I can also do that. I already used #defines to turn on/off the idle/EOC tracking feature, so this is really easy to do.

Originally Posted by AndrzejM

One thing would be good - L/hr display or changing display from L/100km to L/hr during stops.

The code already can display L/hr... but alternating between L/hr and L/100km is an interesting idea. Or did you mean a big numbered L/hr display?

Originally Posted by AndrzejM

Graphs are nifty but not very useful.

The graphs were more of a visual aid to see if a modification (aero mod or engine mod or driving style change) changed anything. The DifFE/time might be generally useful - that ScanGauge E has one, so I figured that MPGuino should also have one.

Originally Posted by AndrzejM

I want to try to change code a bit to read engine's temp instead of pressures.

Engine temperature reading might be tricky, especially if you're just reading the voltage going from the existing ECT sensor to the existing ECM. They sometimes will use two different circuits to supply current to the ECT sensor, depending on engine temperature and internal logic. The low temperature circuit will drive the sensor with a lower current, and the high temperature circuit will use higher current. This is to prevent overdriving the ECT sensor and heating it up at low engine temperatures, while providing accurate ECT readings when the engine is warmed up.


This graph, supposedly for a 1995 Cadillac De Ville, shows a graph of voltage vs engine coolant temperature - note how the voltage changes at 50 C.

Originally Posted by josemapiro

Overall I like new code very much. Great job t_vago! Thanks again

Thank you! I'm just glad to help.

[AndrzejM]

Originally Posted by t vago

The code already can display L/hr... but alternating between L/hr and L/100km is an interesting idea. Or did you mean a big numbered L/hr display?

Haven't found that. Maybe that's because still don't know how exactly setup my custom screen.

I wasn't thinking of big numbered display for L/hr, that's not necessary I think. I was thinking of alternating instant FE display values from l/100km to l/hr when car is not moving. Then you can both see FE when car is moving and engine load when it's idling. It's good for modders to know that value when changing A/C, alternator or PS setup to limit engine load. I was using that with previous code, to see how engine load is changing when for example I'll turn the headlights on or blower.

Originally Posted by t vago

The graphs were more of a visual aid to see if a modification (aero mod or engine mod or driving style change) changed anything. The DifFE/time might be generally useful - that ScanGauge E has one, so I figured that MPGuino should also have one.

Yes you're right DifFE/time is the most useful graph and I was driving with it for a while.

Originally Posted by t vago

Engine temperature reading might be tricky, especially if you're just reading the voltage going from the existing ECT sensor to the existing ECM. They sometimes will use two different circuits to supply current to the ECT sensor, depending on engine temperature and internal logic. The low temperature circuit will drive the sensor with a lower current, and the high temperature circuit will use higher current. This is to prevent overdriving the ECT sensor and heating it up at low engine temperatures, while providing accurate ECT readings when the engine is warmed up.



This graph, supposedly for a 1995 Cadillac De Ville, shows a graph of voltage vs engine coolant temperature - note how the voltage changes at 50 C.

Berta has double sensor setup. One is working for ECU purposes and I don't want to mess up with that. Second one is working with temp gauge and I want to hook up this circuit. I've checked Voltage/temp characteristics some time ago of this circuit and all I need is to change the code to get proper readings. I have everything hooked up to my MPGuino already.