Outboard boat engine fuel consumption

Hi,

I'm in winter hibernation here and thinking about a smart way to measure fuel (gasoline) usage on a old outboard engine.

What i'm interested in seeing is basically how much fuel i'm actually consuming, like Liters per minute or hour. Maybe present a total fuel usage for this trip. And also i think it should be possible to read rpm from the engine.

Outboards like my old beast typically have a sweetspot where it's got decent speed and a lower fuel consumption.

Boat has 12V electrical system with car battery setup, should be possible to provide a stable power to an arduino with a 12v USB adaptor or similar.

I've seen and read some posts regarding flow meters connecting to arduinos, but i think i need advice in an early stage.

It's a carb engine with one-way fuel flow.

I'm a beginner with arduino but i think it would be the perfect platform..

My first thougts in this project in order to get started.. 1. Advice on arduino model suitable for this type of project.. UNO?

2. Suitable displays, LCD vs OLED.. other? I will cut a hole for the display in driver area.

3. Suitable fuel flow sensors. There are cheap ones on ebay from china like this 1/2'' Liquid Fuel Oil Flow Sensor Counter diesel gasoline Gear flow sensor

I have no problems with connections and the mechanical setup but i would like somewhat consistent accuracy whether or not i'm using more or less fuel at a certain RPM. Not sure if that stuff is good enough for this project.

4. Engine has a one wire rpm indicator prewired, i just have to make that within range to read output with the arduino, i guess a safe pulse voltage regulation will be needed. (I'm not sure of the voltage of the rpm pulse). Can i prepare anything before knowing the actual pulse voltage at the moment?

5. Is it possible to store consumption data in arduino over time and even if it gets disconnected from power?

I'm familiar with programming and i am very interested to get started with arduino.

And i appreciate all advices =)

endor: Hi,

I'm in winter hibernation here and thinking about a smart way to measure fuel (gasoline) usage on a old outboard engine.

What i'm interested in seeing is basically how much fuel i'm actually consuming, like Liters per minute or hour. Maybe present a total fuel usage for this trip. And also i think it should be possible to read rpm from the engine.

Outboards like my old beast typically have a sweetspot where it's got decent speed and a lower fuel consumption.

Boat has 12V electrical system with car battery setup, should be possible to provide a stable power to an arduino with a 12v USB adaptor or similar.

I've seen and read some posts regarding flow meters connecting to arduinos, but i think i need advice in an early stage.

It's a carb engine with one-way fuel flow.

I'm a beginner with arduino but i think it would be the perfect platform..

My first thougts in this project in order to get started.. 1. Advice on arduino model suitable for this type of project.. UNO?

Uno is great for development, once you get it working, you'll probably want to swap that for a pro-mini clone from ebay (or a real one - pro mini has same chip as uno, but smaller board - making it easier to fit into projects, and cheaper - but for some of the same reasons, it's harder to do the early stages of development with it), since they're smaller and cheaper than an uno, and then you can use the Uno for your next project ;-)

I see nothing about your project that sounds like it would need one of the fancier boards - you don't need tons of IO's, nor does your project sound like it will need more memory/flash than usual, nor do you need wifi, since you're on a boat and there's no wifi anyway

2. Suitable displays, LCD vs OLED.. other? I will cut a hole for the display in driver area.

Your problem will be daytime visibility. An OLED or color LCD is probably going to be lousy in this regard. Black and white LCD's are better - you can get some nice big ones (with very easy control scheme) at 64x128 resolution from Digole displays on ebay. Get one with backlighting; you still may find yourself modding it to make it brighter. E-Paper screens would probably look really good during the day, but would be impossible to see at night without some sort of extra light - and they're expensive.

4. Engine has a one wire rpm indicator prewired, i just have to make that within range to read output with the arduino, i guess a safe pulse voltage regulation will be needed. (I'm not sure of the voltage of the rpm pulse). Can i prepare anything before knowing the actual pulse voltage at the moment?

Not really. If it's just a pulse, though, it's straightforward to sanitize.

5. Is it possible to store consumption data in arduino over time and even if it gets disconnected from power?

Sure, see the EEPROM library. There are also I2C and SPI eeproms available.

I'm familiar with programming and i am very interested to get started with arduino.

And i appreciate all advices =)

This is a subject I have been interested in for a few years. I have a diesel engine that consumes about 1 to 2 litres per hour. I would like to be able to see the instantaneous fuel flow rate (or near instantaneous - maybe total for a 10 or 20 second period).

The big problem is that I have never been able to find a flow meter that can measure such low flow rates. By comparison the Arduino stuff would be trivial.

...R

Great input, I will get myself an uno and a display to start with. I think I will investigate possible options to the flow meter.

I would like to have a reliable product but with a decent cost. Gasoline and electricity is a combination that I have certain respect for.

I don't really have low-flow problems with this engine since it consumes a LOT of fuel per hour if I torture it. ;)

I will find a good forum section here where I can post continuing progress.. I will most likely need help with some electrical guidance for connecting flow meter and regulating RPM pulse.. but one step at a time.

Thanks so far! :)

endor: I will find a good forum section here where I can post continuing progress.. I

Please keep everything in this Thread.

...R

I would be interested to see a MPG or L/100km figure for the boat. It's one thing to know you're using fuel but are you actually getting to your destination?

For absolute mileage, use a GPS. But then the MPG will vary significantly depending if you are going with the current or against the current. A waterspeed sensor is called a log. There must be many available that will be suitable to interface to the Arduino.

MorganS: A waterspeed sensor is called a log.

I had a Raymarine one on a sailboat and it was crap.

...R

Wow, yeah that would be an evolution of the project, it’s really an exciting idea!

First stuff ordered now.

Since it’s from far far away and it probably take a few weeks before arriving i prepped with this first.

1 Digole serial LCD 128x64 w backlight
1 Fuel flow meter

I will evaluate the quality of the fuel flow meter to see if it feels ok to use, my plan would be to put the meter inside a sealed box for fire hazard purposes.

The uno will also be ordered, but with overnight shipping locally… and then the fun begins.

I also made a mockup (attached) just to get an idea of what to display.
Added voltage metering for starter battery and “house” battery, nice to know if it’s charging or not.

Thinking now how to mount the display, since it’s quite raw. But i’m not remotely close to mounting yet so i’ll let it grow.

There’s always someone who built stuff like this before :wink:
Use google translate for the site

He is using this flow meter for his project:
B.I.O Tech FCH-M
0,05-3,0l/min

http://www.conrad.se/FLOW-M.-FCH-M-POM-LC-G1%2F8%2F2XM5).htm?websale8=conrad-swe&pi=150391&ci=SHOP_AREA_14741_0231810

This feels like it’s a bit higher quality and well documented and with a higher pulse rate… I guess it means higher accuracy at low flow.

I will give it some thought…

Behold! The UNO has arrived - the fun stuff begins.

I have connected up a 12V power supply to start testing.

Two resistors that step down the input to be able to fit within the 0-5v span.

R1 = 100k.Ohm
R2 = 10k.Ohm

This would give a possibility of a voltage input up to approx 55V before reaching an output over 5V.

No serious protection, and i’m wondering if it’s wise to have the uno GND with raw connections to the external batteries negative like this.

After some readings and calibrations of the calculations i have an reading on the arduino that is consistent with the multimeter.

The code is from this site with some minor adjustments:
http://startingelectronics.com/articles/arduino/measuring-voltage-with-arduino/

// Define number of analog samples to take per reading
#define NUM_SAMPLES 10

float boardvoltage = 5.00;      // This is the measured 5v reference that is output from the board, this is reference.
float calibrationA0 = 11.121;   // Calculation factor for a0 resistors GND--10k--A0--100k--External V+


int sum = 0;                    // Declaring sum of samples taken
unsigned char sample_count = 0; // Declaring current sample number
float voltage = 0.0;            // Declaring variable for valculated voltage

void setup()
{
    Serial.begin(9600);    
}

void loop()
{
    // take a number of analog samples and add them up
    while (sample_count < NUM_SAMPLES) {
        sum += analogRead(A0);
        sample_count++;
        delay(10);
    }
    // calculate the voltage
    voltage = ((float)sum / (float)NUM_SAMPLES * boardvoltage) / 1024.0;
    
    // send voltage for display on Serial Monitor
    // voltage multiplied by calculation factor measured from Input voltage / output voltage

    Serial.print("Battery 1: ");
    Serial.print(voltage * calibrationA0);
    Serial.println (" V");
    sample_count = 0;
    sum = 0;
}

Battery1_test.png

Battery1_Measure.jpg

LCD arrived and up running!
Doing a lot of finetuning in the code right now for vcc 5v reference for measurement and timer routines…

The red cheap flowmeter from china was utter junk so after reading around i found the original version and ordered one used in good condition for $35.

Thanks to “malebuffy” (!) for sharing his experiences.

See his blog and read through his posts around a similar project

endor: i found the original version and ordered one used in good condition for $35.

I'm interested to hear how the flow meter performs when yo get time.

...R

Ok. I have received the flow meter now and started to hook it up.

Is there anthing special you would like me to try with the new meter, now when i do the tests?

Found some differend setups but this is the one that i have hooked up now.

D2 Input, high = sensor cable from meter
D4 Output, high = +5V to power for the meter
D6 Output, low = GND to power for the meter

I’m working to find decent ways of reading the sensor both for testing and calibration but also in the project…

endor: Is there anthing special you would like me to try with the new meter, now when i do the tests?

Thanks for asking.

I am interested in is what is the lowest flow rate it can measure. I do appreciate this may not be relevant to your situation.

...R

I could be wrong, but I was under the impression that fuel consumption in cars was calculated by measuring air flow and the data from the lambda probe.

Shpaget: I could be wrong, but I was under the impression that fuel consumption in cars was calculated by measuring air flow and the data from the lambda probe.

I want to measure the fuel usage at idle, and a little above idle in a simple 35HP industrial diesel engine with no electronics.

...R

Sounds like you have a constant and predictable consumption, so why do you need a live measurement? What's wrong with just timing how long it takes to consume a certain amount and assuming it will stay constant? A fuel gauge and a clock should be all you need.

I wouldn't bet you can easily/cheaply measure the flow to the same accuracy as just applying a previous calculation, even when not accounting for errors due to different loads and variations in atmospheric pressure/temperature/humidity.

Shpaget: Sounds like you have a constant and predictable consumption, so why do you need a live measurement?

The load varies as it is generating electricity and I want to figure what is the most economic setting. And it's not strictly at idle - I just mentioned that so everyone would know it is not being asked to produce 35hp.

Also it would be interesting to have a device that could easily be attached to the fuel system of another engine (eg petrol genny) to compare the economics. Suppliers are notoriously secretive about their data.

...R

Robin2: I want to measure the fuel usage at idle, and a little above idle in a simple 35HP industrial diesel engine with no electronics.

...R

measure the time it takes to consume a liter. that will give you the minimum rate. that would be a value that can be used by all.

I have an older car and would love to get such performance information

dave-in-nj: measure the time it takes to consume a liter.

Folks we are distracting from @endor's Thread.

I know all the usual ways to measure fuel consumption. If the meter @endor is trying is suitable I would like to have a real-time readout. It takes about an hour to consume a litre.

...R