I live up north and out in the country so I have a propane tank. I don't know whether you want to call it laziness or whatever but I don't like going out into the cold to check the level on the tank. I was thinking about the water meter mote. Could that be modified so it would alert me when the needle on the propane tank gets to 20%? If someone has a different suggestion please let me know. Thanks
cant help you, but maybe a picture of the installation can make it easier to find a solution.
Here's where it'd go
(http://i.imgur.com/rsj0ziu.png)
I think the water meter mote is designed to count rotations of a spinning wheel whereas you are looking to detect the position of a needle on a dial. There are commercial solutions, see http://fuelminder.biz/will%20call%20monitor/will%20call%20monitor.html for one example. I believe this relies on a specific gauge (Rochester R3D-LP http://www.rochestergauges.com/products/R3D-LP.html) that allows for an external Hall effect sensor. If you don't have a gauge like this detecting needle position is a relatively straightforward pattern recognuition problem. The not straightforward part is transmitting an image of the dial using a battery-powered Moteino sitting outside in the cold.
Posted before I saw the picture. Your gauge is remote ready so you can use a Hall sensor to read the position of the dial. Either reverse engineer the sensor listed above and build your own or figure out which wires carry the sensor information and transmit that via a Moteino.
Quote from: Kilo95 on January 22, 2016, 04:22:40 PM
I live up north and out in the country so I have a propane tank. I don't know whether you want to call it laziness or whatever but I don't like going out into the cold to check the level on the tank. I was thinking about the water meter mote. Could that be modified so it would alert me when the needle on the propane tank gets to 20%? If someone has a different suggestion please let me know. Thanks
Load cell under the Tank? Be pretty accurate... Somewhere in this forum I saw someone using these.
Tom
UPDATE: Here's the thread: https://lowpowerlab.com/forum/index.php/topic,1091
However, looking at your photo, you're tank is full. Relax... ;)
Quote from: jra on January 22, 2016, 05:20:30 PM
Posted before I saw the picture. Your gauge is remote ready so you can use a Hall sensor to read the position of the dial. Either reverse engineer the sensor listed above and build your own or figure out which wires carry the sensor information and transmit that via a Moteino.
@jra, Good suggestion.
@Kilo95, if you use a 2 or 3 axis magnetometer, relatively inexpensive from Honeywell or Xtrinsic MAG3110 from Freescale, you can read the angle almost directly. I didn't realize the needle was magnetized. Good to know. I might look into this. Of course your fuel company might get cranky about blocking the meter.
I think the load cell would be the way to go. I'd do that if my tank wasn't buried!
Tom
I think I might try the magnetometer. Thanks for the suggestions. They only come out when I call them. Don't think they'd say anything. If they do, I'll just switch to natural gas. :D
Quote from: Kilo95 on January 22, 2016, 07:52:56 PM
They only come out when I call them. Don't think they'd say anything. If they do, I'll just switch to natural gas. :D
Wow! I don't have Natural Gas as a choice at either of my two locations and, if I told the LP supplier, "Well, I'll just look elsewhere." they would tell me, Great, we'll suck out the gas that's still there, take the tank and all the hookups and, uh, good luck finding someone else...
Sigh. However, please keep us abreasted of your progress on this. I really would like to install sensors on my various tanks.
Tom
PS: I like the Freescale sensor but it will be a challenge to solder. However, I like it so much that I'll probably try it on another project I'm working on so let's stay in touch.
Jra, I'm thinking I could get the fuel minder setup you suggested and run it the 40' or so into my garage (where it's warmer and batteries would last longer) and try to figure out how to hook up a moteino to it there :) thanks for the suggestions
Quote from: Kilo95 on January 23, 2016, 06:36:03 PM
(where it's warmer and batteries would last longer)
What temperatures do you have? A lithium primary would get you to -40C (coincidentally -40F)...
Tom
Coldest I've seen is -25 to maybe -30. So that would work with a few degrees to spare
I think the EESY310 (https://lowpowerlab.com/shop/sensors/EE-SY310) would totally work for this. It can tell when the needle is beneath it very well if the background is an IR reflective color like white. The sensor is very responsive and has a hysteresis so it shouldn't give you a false read. The dial might need to be covered if sunlight hits it or light throws it off, experimentation will tell for sure.
FWIW if there's enough "magnet" on that needle even the omnipolar sensor (https://lowpowerlab.com/shop/sensors/magneticsensor) I use for the garage doors might pick it up.
Quote from: Kilo95 on January 23, 2016, 08:11:16 PM
Coldest I've seen is -25 to maybe -30. So that would work with a few degrees to spare
The other thing about your project is that it can be EXTREMELY low duty cycle. I would expect reporting in once every 24 hours would be more than enough to know when you need to refill.
Let's see... 40mS (80 if you needed retry) to report it's reading @~20mA (average current) max, 86,400 seconds to hibernate, drawing less than 1uA. Yup, your battery leads would rot before your battery was dead. Of course, Joe would try to run it with a coin cell battery.
Tom
Sounds great. I'll have to look at it. My tank has a massive lid on it that I keep shut which would keep the light to a minimum
so felix, it looks like i could just purchase the WaterMote kit with the EE-SY310 for this application, am I correct? with maybe a few minor changes
I think so, you would just need to make some adjustments to the watermote sketch to make it battery friendly (ie add sleep code for everything) and only take measurements maybe once per day as Tom suggested.
And you'd need to tweak the position of the reflective sensor on the dial so that it sits against the white background. I would think somewhere between 20 and 25 in your dial should work.
Awesome.
Quote from: TomWS on January 23, 2016, 07:43:37 PM
What temperatures do you have? A lithium primary would get you to -40C (coincidentally -40F)...
Tom
In my experience (over a year of ongoing tests) cold kills ANY battery faster than your device will drain it. I have sensors running on 3V lithum cell for 7 months (transmitting temperature/humidity and voltage every 5 minutes), and then they die when it's below -10F in less than 30 days.
Yes I think that should work and its a pretty cheap attempt.
On the eesy310...connecting it to the moteino...red to the 3.3v on the moteino, black to ground, and where does the white go? Where's te easiest place to get the three wire jumper you used in the watermote setup to connect it to the moteino? where's the best place to put the sleep code so everything is covered?
Depends on what you want to do with that signal. It will flip state when it crosses colors. Just connect it to a digital pin, then check when it changes state, send your packet, etc.
If you want to use it like a pulse counter with my WaterMote sketch then connect it to D3 which is a hardware interrupt pin which is expected to flip very very fast and needs an interrupt to count the pulses.
Ok. Great. D3 it is. how do I adjust the sleep one so it only checks once a day
I think that the Watermote reads the cyclic passage of a needle in front of the sensor and counts how many times something happened. That is not your case, as far as I can see. What you need is either a small Wifi camera pointing to the needle or measuring the weight of the tank and sending it wirelessly to another Moteino to display it on some sort of LCD. I would go for the weight sensor, since it is a trivial mater for a Moteino to do all that.
It's a 500gal tank. Plus 400gal of propane. I wouldn't be able to get it under there. Also I think that's over the weight limit for most of the scales I saw. Thanks though
You could build a platform with several sensors to distribute the load and set the tank on top of it, then average and sum their readings.
The simplest solutions are always the best choice.
http://www.wikihow.com/Measure-the-Remaining-Propane
I don't see how you can read the needle position if it moves slowly along a scale.
It'll just let me know when it gets down to 20-25%. That's good enough for me😁
You can sleep 8s at a time. See my sketches.
Do the math for 24h, gives you the ~ # of cycles.
i got that added. copied from sonarmote sketch. so with the watermote sketch, what kind of readout will i get on the gateway? nothing until it gets down to 20%, then it'll give me a reading in gallons? i'm trying to figure out how to be either a off or on. (>20% or alert at 20%). any suggestions?
No, the gallons thing is where there is a pulse. You have no pulse or anything like that. When your dial indicator gets to 20% it will obstruct the sensor and the sensor will simply go LOW (or HIGH... I cant remember now). Then you know it reached 20%. Then you send your message.
I guess you could install several of these sensors at various points on the dial. Like 20%, 40% 60% 80%. Then you can use digital pins to power them for low power, (dont use VCC or it will drain your battery fast, they are IR LEDs basically). Then power each once a day, read the status and report the last known status until you reach 20% or the lowest, at which point you can setup an alert. Many ways to do that ... you got tons of example sketches and metrics to follow. A bit of javascript and c++ practice can't hurt anyone :)
Looking at your dial I noticed that it says "REMOTE READY" on the black tag. A simple google turned this out:
https://www.youtube.com/watch?v=XeCplibHX_8 (https://www.youtube.com/watch?v=XeCplibHX_8)
If you notice in the video, there is a specific sensor built for that meter. Here are some examples: http://www.tekelekgroup.com/en/tank-monitoring-systems/lpg-gas-sensors/lpg-propane-sensor.html (http://www.tekelekgroup.com/en/tank-monitoring-systems/lpg-gas-sensors/lpg-propane-sensor.html)
http://www.rochestergauges.com/products/R3D.html (http://www.rochestergauges.com/products/R3D.html)
That last one has description on how to connect a hall sensor.
You can try to place a hall sensor in the socket and connect it to the Moteino.
I have been unable to locate those resistors in the photos of the eesy310 in the store or the watermote page or find a schematic. Sorry for the trouble
Look at the purple PCB....... it's tiny. There are 2 resistors "10k" and "270ohm".
You can't miss these but let me know if you still can't find them.
Identify the resistors using this:
(http://education.rec.ri.cmu.edu/content/electronics/common/resistors/images/400px-Resistor_color_code_chart.png)
I see what looks like a diode on each side of the photoelectric sensor. Next to r1 and r2.
that is an arrow............................ :'(
(http://i.imgur.com/5v3P3J2.png)
Does this help?
Absolutely. Thanks. I couldn't find any pic with them installed. Thanks.
Sorry, the existing ones were SMD resistors :P
No problem. Least I don't feel quite as much like a moron.
Sok, don't we all feel that way at some point on this journey ... every time it happens to me (fairly often) I'm reminded where I started from, ie a blind, bald and naked wandering through the clouds of EE illiteracy.
Well I'm still there when it comes to programming. Lol. I can copy and paste some stuff but that's about the gist of it so far. Lots to learn