Making an Arduino-based fuel gauge 

Add some averaging over time. Loads of benefits. Smooths out the noise from the sensor, eliminates the slop from the movement of the fuel and gives you a finer resolution because you benefit from the proportion of time spent reading at each course reading.

As an ex-IT guy myself, I found that bloody interesting. Nice one Stu.

Hey Stu that was rather interesting and I can see where it could be very useful. Diesel is lighter than water, I trying to remember numbers I haven't used in 30 odd years... water is .48 psi per foot of head. Diesel is .45 psi per foot of head I think it is, this should help you work out the range you need for your sender or transducer for your fuel level computer.

Absolutely love this channel for the sheer variety of content you offer 👌 wanna paint a boat? Build a Detroit? Wire Any 12/24v system? Do anything boat related? Code a bloody Arduino? Come to Dangar marine! Please Keep it up mate

As a former BASIC Stamp programmer, I found your Arduino segment very interesting!

Started off way above my head. By the end it made more sense to me. I feel like I have learned something new and useful. Thanks 😊

Nice article. I’ve rigged up a 5psi sensor (giving over 1000 pressure points from 0-4m). With some heavy duty smoothing Arduino code to accept up to 5 sensors/tanks the readings remain rock solid in my water pipe tests even when shaking it around. Next step to try it in boat.

Yet another string to your bow that you are showing us! Mechanic, welder, boat handler, knot tyer, painter, diver, fisherman and now computer programmer. Waiting to see something that you can't do. Good news that it might just be growth on the prop causing most of your vibration/oscillation issue. Can't wait for Renko to be back and a decent cruise that doesn't end up at a shipyard.

Refurbishing a soldering iron tip: File the tip back to clean copper and re-tin. When using a soldering iron, dip the hot tip into flux paste or Bakers Fluid or clean with a soldering station pad to ensue a clean uncontaminated tip. Cleanliness is the secret to trouble free soldering. I hope this helps

Thanks for the warning. It prepared my brain for the kind of learning to expect. Challenged me to stick it out and try .

WOW. It is amazing how quick the barnacles form.

I love this project - I’m a massive tech-head/geek.

Love the change in pace, and well explained

Alot of that went over my head.... But as an Irish man I felt compelled to watch!... GO Ireland 🍀🇮🇪

Navy convention is for port to be even and starboard to be odd. Ships use tank curves and measure depth to derive volume. Depth can be measured through pressure, echo/radar, or dipstick/sounding tape.

Those Arduinos are amazing little devices. I built a home/yard security system that detected intrusion and plotted motion on a diagram of the house on my laptop using a kit made by them about a year ago. Works great. The sensors that showed a door or window opening was straight forward. The motion sensors were accurate +/-6 feet and had to be majorly tweeked by adjusting values in the code for it to show accuracy of +/-2 feet on the laptop diagram. I think you may have to do same to get an accurate reading on your fuel gauge. What I loved was all the code was availible on their website and the whole thing was sold as a kit online that cost about $150 (U.S.). Hope it works for you. Once you work out the tweeks, it should. Awesome video. Definately different and not boring. See you in the next one.

another sensor you can try is " Laser Distance measurement with 6pin VL53L0X " or the ultasonic distance sensor , mounted in top of tank , bounces signal off liquid level .

Love the Irish Jersey, I am really enjoying all your videos while on lockdown here in Ireland. I own a Princess 37 grp cruiser on the River Shannon and really enjoy the tips. Keep it up , Thanks.

Thanks Stu, that was very interesting even for a guy 50+years of age. Keep up the great work.

Hi Stu, You talked about building up the thickness of antifoul . With my experience over 15 years with a displacement cruiser. Less is more. Only apply enough to work between your regular out of water maintenance period. As it is design to release and wear away. I have found that build up of old antifoul to thick and painted over will eventually loose adhesion and flake off taking your new coating with it. I found that it was better to sand old antifoul well back .Good idea to each time you put a new coat of antifoul is to use a different color so you can sand back to the last old color. Love watching your projects.

The Arduino is digitizing the analog signal. So, when you switched to internal 1.1V reference, the detectable voltage difference becomes smaller, as you stated by a factor of 5V/1.1V = ~4.54. So, the electrical noise in and around Arduino's electrically un-shielded circuitry is now being seen and digitized along with your signal. You are dealing with signal + noise which is why the values are bouncing around. I would consider enclosing the assembly in a grounded (battery neg terminal is fine if powering from the battery) box. You can, of course, do averaging but that will slow the update to the display (you must collect n readings, then compute avg = (sum of readings)/n). If your analog pin read conversion rate is, say 1 per second, and you want to average 10 readings, your display will not update for 10 seconds UNLESS you write a running average algorithm , Not sure how the Arduino will handle that if you are using large n window. Then you can still get a 1 per second display update rate but NOT UNTIL the first n readings have been taken. Finally, the noise reduction goes as 1/square-root(n) so you can get a lot of that noise removed by large number averaging BUT that is a band-aide at best. First, isolate/eliminate the electrical noise sources and you may not need to average to get a more stable reading but if you still do, it will take far less averaging once you have minimized the electrical noise sources. Cheers and have fun! Good stuff!

My fuel gauge was the antique analog method using a 5 foot long organic sounding rod which closely resembled a broom stick. This was calibrated whilst filling the tanks from dry at 50 litre intervals with a notch inscribed into said rod. This proved to be infallible, unlike electronic contraptions that seems find the fine sea air disagreeable. Even if the swab of a deck hand did loose one over the side whilst beating a marauding shark around the snout, we then substituted the handle of the deck brush, the draw back was every time he scrubbed the decks he stank of diesel.

Nice one! To smooth out the data, a simple first order filter works well. filtered value = (filter const* prev value) + ((1- filter constant)*current value) Grab the "blink without delay" sketch from the arduino examples and take samples every 200-300 milliseconds. Filter const can range from 0 to 1 (no filtering to infinite filtering). Start with .85 to .95 and things should settle down nicely even in rough water. You can fiddle with the algorithm to detect a refill or a leak, but that isn't necessary. Again, excellent presentation -- Thanks!

I'm a programmer as my profession, and this was really interesting to see how you programmed the device to actually do something practical in the real world. Often times I only see the results as a computer application, or a web page. Really cool and refreshing to see programming being useful for something I am interested in!

Truly a jack of all trades.

Once a hacker always a hacker. You're not fooling anyone with all this wrench-spinning, welding and marlinspike seamanship. :-)

I would concentrate on getting a more suitable pressure sensor. Using the current one and amplifying the reading by using a 1.1v ref plus mapping means the reading will be all over the shop when you're under way. Using a new sensor plus smoothing code (in the arduino website) and I reckon you're on to a winner 👍 Keep up the good work 🚢

Great work Stu ... was not expecting this one but makes sense. Can then expand later for weather, water speed by power created from a turbine put relative to kn etc.

Oh I like. You've got me thinking about an Electronic flow meter now.

Just ordered an Arduino style kit on Amazon, want to give this a shot now. Around U$18 for the starter kit with electronic sensors, components and other bits and bobs. Thank you, Stu. Love your channel.

Not your usual output as you say, but interesting none the less. I enjoyed it! Running a boat requires lots of different skills, and this is a great example of that.... boating is not just spanners, welding spatter, paint fumes and oily rags!!

Stu's a coder. Diesel fuel weighs ≈7 lbs/gallon. Water weighs ≈8 lbs/gallon. The nonlinear part of this equation is the boat's tanks have a non-uniform cross section as you go up. I think the weight varies with quantity of liquid above the sensor, not just the height. Ron W4BIN

I’ve mentioned it before, but now is a excellent time to do a colab with EEV blog. That would make for one epic Aussie video!! 👍👍😬

I love this stuff. As tinkerer and computer science student, just seeing simple code produce a practical result is great :D

Could not be more excited about using the Arduino to measure system pressures and temperatures. Just had an undetected cooling failure that has cost me $15k US on an older IO drive resulting in a fire. Imagine if I had the Arduino checking the exhaust water pressure and temp then sounding/flashing an alarm if it's out of spec. Totally appropriate subject for your channel. Many Thanks.

Mate your genius! I’ve been struggling with a float switch on my pressure washer buffer tank for months, because it’s all mounted on a trailer it doesn’t last 5mins, pressure sender has no moving parts so should withstand bumpy roads and dodgy driving alot more. All I have to do is program it to send a kill signal to engine once a set minimum value is reached.

Thanks so much for explaining this, I’m going to make one for my beer kegs so I can assess the volume, this is just brilliant!

Surprised your US viewers aren't losing their minds over your correct pronunciation of Solder.

Definitely have not given up! This project is awesome. I was so excited you got to take the first sea trial. The dottie(sp?) updates really round out the video also.

My first thought was to have a smoothing function to average inputs. Then I see guys far smarter than me have already offered the same. Love me some subscriber help!

Another method of measuring tank level is with a capacitive sensor. Several nice videos on how to build a sensor to do this. One nice thing about this is it likely could detect the presence of a significant amount of water in the tank because the dielectric constant for water is so much higher than for diesel.

Two things I worked with today, Differential pressure switches and Trane controllers. Nice!

Thats awesome! I've fiddled around with arduino myself but to see you use it for a legitimate purpose is pretty cool

That pipe over that Mac book, hurts. Excellent proyect!

Wow Stu, you are really good with that stuff!

Pretty nifty way to read the fuel level. Glad that her leg is getting so much better :)

You aren't only a good boat mechanic you are a professor at technology also. I always measured diesel fuel tanks in gallons you got me lost on this percentage stuff.

The sound of daffy walking at the end was like a pegleg pirate walking across deck. You should put an eye patch on her and video her on the boat, just for fun, haha. I love your yard too. It reminds me of my grandfather's doorless barn in the 60s. Nothing metal was thrown away, and chickens free ranging outside, but nesting boxes tucked in the nooks inside. I love the boat building, and even the electronics. I actually work with computers but if I had followed my passions in my youth, I might of been a shipwright of old tall ships.

That was great Stu, a completely different part of the whole project that is totally nesescary. The way you explained it made no sense first time around, but I can go over it till I get it in my head! THANKYOU!

You could try using an automotive MAP sensor. They come in 1, 2 and 3 bar varieties and are cheap. They won’t like diesel though so will need an air column. This is how your washing machine senses the water level, a tube to the bottom of the tank with a pressure sensor at the top and air in between.

Fun to see tech being applied to a practical situation.

Peter from Sweden already mentioned using a second pressure sensor to get an atmospheric pressure as reference. You actually can get inexpensive differential pressure senders/sensors from camping supply stores or get them from Alibaba for a fraction of the price here in Oz. You could also mount (glue) ultrasonic sensors on the outside of the tank and use the change in signal for the digital I/Os. If you space them according to tank volume, you avoid calibration issues. There are some of these things available for caravan tanks and don't cost an arm and a leg. (or direct import from Alibaba).

For a sender, try taking a look at stuff for HVAC monitoring or Barometric pressure measurement. If you put a hose Barb at the bottom of the tank and run a small hose up above the tanks, you can monitor air pressure instead of fuel pressure. There are barometric sensors (BMP180, to name one) that will give you insane resolution in measurement of small air pressure changes. Last time I did this, I epoxied some wires and the baro sensor inside of capped PVC with a barb. Worked awesome for water level sensing.

Thanks Stu! I've been thinking about dipping a toe into the Ardwater. Coming to the end of a major project at the moment, maybe now is the time. They seem to be pretty unlimited in what they can do.

I am impressed. Way over my head, but pretty cool. You obviously have some knowledge of programming language. A whole new dimension of Stu. Very cool

Good technical information, updating old systems with more reliable gauges. Enjoyed the simple practical experiment. Thanks for another professional tutorial.

That's the first episode my kids have gathered around and watched with me. Apparently nerdy teens know all about this stuff, and are quite amazed to see bogan "Dad" style applications...

I'm a computer nerd and programmer by trade (game dev, mobile lately) so seeing you peck around in code was actually enjoyably entertaining. Analogue, lol

I like it a lot. I’m actually building my throttle and gear change with an arduino. I also have to flatten out the input of the joystick. You can do that by comparing the previous value with the new one and only apply a change if the difference in value exceeds a certain number. This number is a variable where you can play with to fine tune!

A rail to rail op-amp would allow you to use full the 5V resolution in the Arduino ADC with the lower voltage range from the sensor. Basically it would allow you to electronically tune the signal to match the ADC rather than mechanically tuning the tube and sensor.

Stu I commented to someone but want it at the top level: use a cheap efficient buck converter to step 12V to 5V and power the board directly. This is what I do for Arduinos I sell to boat owners.

I really enjoyed this video and you demonstrating how it will work.

Loved this one Stu. Fairly new here and now binge watching all the old episodes! Subscribed and thanks for sharing your work.

Just found this channel this morning and I have spent the day binge watching. Love the work and I have lived the ups and downs of boat projects. I have only seen one thing that I can suggest a tip on and that is put a drop of none acid silcone under your heat shrink. Water proofs it a bit better and gives the bare wires a bit of support. Wires snapped at a terminal is always a problem on yatchs.

That stuff is nice for a reference, but I'm old school and would want sight glasses. Have a great day.

Also u could add 4 float switches to outside of ur tube for 3/4 1/2 1/4 and reserve. Just use couple of leds in the unit u mount display in. Plenty of io on the board and wouldnt need to change ur display as indicators are the leds. Easy to add to your sketch.

Something like BSP (British Standard Plumbing), straight thread or NPT (National? Pipe Taper, same size but tapered) which use the internal pipe diameter as the bit to be measured. Pipes were originally iron. So there.

And you program too!! You are a jack of all trades!!!

Sorry Stu, I did stay to the end but if it was me I would have to use the " Yosemite Sam " method to check the fuel level in my tanks. Unscrew the lid to the tank and hold a match over the hole to see how much fuel is in there.

my head exploded !! the stupid runs deep in my family , but I have no doubt someone understood and will be able to help you more than I ever could great vid ….I think :)

Personally node red on a pi for any iot deployment. Can use it for so many other function. Can be configured for total boat management and control. Has some great ui tools and dashboards.

You can recover your soldering iron tip with some fine sand paper or emery cloth. Then dip it in some flux if you have it then tin the tip the first time you heat it up. Then use a wet sponge to clean it after use to clean the tip between use.

Stu, Water exerts a static pressure of 0.433 psi/ foot of elevation. What you need is a differential pressure sensor that has two pressure inputs. The low pressure input should be left open to atmosphere. The high pressure input is connected to the tank or gauge tube that’s attached to the tank. The reason for using a differential sensor, is to avoid errors that would be created by changes in barometric pressure. At very low pressure ranges like this those errors would be significant. Diesel fuel is about 76% as dense as water, so the actual pressure/ foot will be lower than water by the corresponding amount. I would try to find a sensor that has a maximum differential pressure equal to a foot or two more than the actual depth of your tank from full to empty.

If it's any help, I definitely enjoyed this episode. electronics, arduino, etc all good fun.

Hi, enjoyed the technical video. Shocked to see the amount of barnacles on the prop, of course it will disturb the balance of the prop. Great video 👌🇬🇧

Interesting project. There's a lot you can do with arduinos once you've got a basic understanding of them. (and they're not that difficult) Don't forget to add a filter to the sensor (not all fuel is clean) and you might also want to attach the sensor to a valve on your tank so you can check the sensor without spilling fuel. It's pretty easy to plan ahead for maintenance when you're not doing mass production and counting pennies. I did get a chuckle that you soldiered the sensor in place without cleaning up the bad soldier joint. When your iron gets badly corroded, use a grinder to take the tip down to bare metal then tin the tip. It will eventually oxidize again, but it will be usable for a while.

Stu; you might want to add some lines to your code to check for 'out of normal' readings and go to an alarm output. eg below range pressure may mean breather blocked and pulling a small vacuum or above full tank pressure may mean blocked breather and building static pressure. You could even set alarms to tell you to balance tanks if the difference gets to great Another thought may be to map litres to your sender voltage so you can display remaining fuel volume

So much yes! So many things I want to do with arduino.

Way to go Stew.... enjoyed the information, and will probably be using it soon.

Loved it! Great example of how inexpensive electronics can be adapted for specific applications. Cal curve for the win!

Daffy can scrat again! Beautiful

Hey Stu, try using a rolling average for the sensor value. Your readings are jumping around quite a bit and that’s without the movement of being on the water. Basically, you want to take as many readings as you have memory to hold (maybe 20-30), then take the average of those readings and use that to calculate the percentage. Just have each new reading replace the oldest reading in the list. It will act as a buffer and some of the noise will cancel out. You also don’t have to have every single sensor reading update the display, you can set it to update every few seconds to save processing power.

This was a great episode. I’m definitely not a tech person but it was really nice to learn few things here! Cheers!

You could add a third pressure sensor to compensate for atmospheric pressure

Stu, really enjoyed this video. Been meaning to mess with an Arduino for a really long time.

If you use a pipe from the top with the sensor at the top it works well we use that system in water tanks on floor scrubbers if you google a Tennant t16 waste water tank you should find a good pick of the set up

That prop was knarly! Little buggers!!

Darned good idea. You might find you need to damp/smooth read display to get decent readings when the boat is moving/sloshing the fuel around. Should be able to do this in the Arduino code. E.g. measure every 5 seconds and show the average of the last 20 readings. The other thing worth thinking about from my point of view is moisture/corrosion. Arduinos are not intended for wet salty environments.

Thanks! You got me inspired to order the things I need for my project. Arduino based remote control for my autopilot. It's a Raymarine talking Seatalk :) I'll be using the same display shield you use to display what is happening and the buttons to control the autopilot + I'm adding a wireless remote also.

Awesome job Stu. Thanks for the fun 🍻

This was a great video Stu! I took an automotive electrical class and it covered much of the electrical content you've encountered on the boat and some content of this fuel guage project.

ok, do that many viewers really hate anything electronic so much that a warning had to be used?? C'mon folks, all of these videos are educational and great content! Thanks for the updates Stu, another great installation in the life of a trawler owner.....

Awesome video!!! I’ve been watching you for 6 months and this is definitely one of my favorite. Keep up the good work.

Hi, would be interesting to see a follow up video showing the final product, and mainly the type of sensor you decided to use. Overall great solution, but seemed that the sensor had a too wide range for this application. Looking forward to see the end result!

Brilliant Stu! Glad Daffy is gaining use of her leg👍

After seeing those barnacles on the prop makes me glad I only have freshwater lakes and rivers around me. I couldn't take the constant battle trying to keep the boat clean.

I Stu, I'd be inclined to put a physical fuel gauge on it too. You know like 1/2 inch 90° elbows, one at the top of tank, one at the bottom. Facing eachother with a piece of clear tube inbetween. So you can see the physical fuel level. If you know what I mean.

Great project to work on and working like you want. Enjoy your videos and content.

Great information ,we all need to get digital savvy. That prop was nasty , hope it solves the wobble.

Excellent! Happy to see how easy programming can be for the “duck tape & vice grips” crowd. Using beer for your tube of fluid would have added amusement, and hysterical protests of waste...