4.8 Fuel consumption / Trip Meter Project

I'm working on a fuel consumption meter and trip meter. I propose to display lph, distance to empty, fuel used since refill, fuel used since trip reset etc etc

Here is a picture of the prototype. The numbers on the diplay are 3223 & 5015. The 3223 is 32.23 km and the 5015 is the ml of fuel used for the trip. The number 15 is the l/100 km which is well rounded off.

Attachment 29818

What I am seeking is the injector cc/min and injector opening times.

I have assumed a 400cc/min injector with a 1ms opening time. The fuel calcs appear to be about low by about 15%, so my best guess is the injector is about 450cc/min. Hopefully someone could confirm?
This would make my numbers line up. I generally get around 18l/100km.

for the interested techo, I am sniffing the VSS from the CAN bus and directly measuring the fuel injector pulse width.

More to follow.

Skip

Just a quick update. Did some 350kms with 450cc/min assumption and 1 ms injector opening time. When i filled the tank my fuel used calculation was only out by less than half a litre. So this is around a 1% error which i am very happy with.

More to come. Skip

far out mate thats awesome you could probably market it and sell it (idea or otherwise)

but frig my head hurts after reading that

Thanks, i'm working on the user interface and a larger graphical display. I will see if there is any interest and go from there....

Sent from my GT-I9210T using Motorculture mobile app

I have been playing around with a ardunio and a similar 2 line display.

I just ordered a couple of IC2 serial displays as the ardiunio bay board display I baulky and hard to mount in a box, Im thinking about mounting the serial display below the rev meter on the dash of my gq. I have the unit displaying my lpg level, distance to empty, battery volts and auto dimming when the head lights are on. Then next step is internal and external temp sensor and engine temp / oil pressure sensors.

Hi GQ TANK

I would be interested in how you calc your fuel consumpsion. I measure the injector pulse width. I also have gone with a 128 x 64 dot graphic display using the u8glib and m2tklib libraries. These work great.
What devices are you connecting with the i2c ?
I also have ds1307 rtc which i save odo and fuel variables to..... regards skip.

Sent from my GT-I9210T using Motorculture mobile app

Been working hard on the user interface. Here is a picture of my progress. Im fairly happy with the progress.

Attachment 32051

I will put it into the 4b for a longer trial.
skip

Hi,

As my gq is a carby, Im just using the average l per 100k I have obtained over the last year (24/100).

I have tapped into the LPG sendor from the tank and take a number of readings that are averaged out - as the level can jump when I go over bums

I received a couple of I2C temp sensors and the I2C 2 line display. The version I got does not have a controlled back light (its on or off only).

I have ordered a couple more from a another vender the has a backlight control.

Using the ardunio and the I2C display is so easy and its only 4 wires.