Anyone up for voluntering for a pic project?

[Harry Bloomfield]

What is needed as output can vary based upon how complex you feel inclined to make it.

1. A single LED which flashes slowly at 10% left, flashes faster at 5%.
2. An LCD bargraph display showing exact level.
3. An LCD showing an actual amount of water used.

A piezo sounder might be useful for 1, 2, or 3, but would need a cancel button, but that would have to rely on it being set for the barrel size.

There are at least three alternative barrel sizes to my 50L, version number 3 would be fine with any size. 1 or 2 would need to be customised for each size, to make it salable. 3 would be fine counting consumption up from o to the barrel size, the user can work out the amount remaining. So I'm favouring 3.

The flow sensor output is an Hall Effect switch, 1 pulse per 2.25ml/444 per litre/22222 pulses per 50L. - how well the three terminal (+, grnd, output) sensor works I don't yet know, but that can be fed from 5v too (5v to 18v), it draws 15mA which I assume is the max when counting. I'm expecting delivery of that in around 3 weeks.

Maximum flow rate of the pump, unrestricted is around 13 litre per minute. As it pumps through flow restrictor at the taps, it will be much less that this, but the maximum needs to be kept in mind in the design. So 444 x 13 = 5772 pulses per minute, 962 pulses per second.

During pump use, the display can take a back seat if necessary.

For development purposes, if its an LCD display, would be good if it showed to two decimal places.

It doesn't need to store the barrel contents through a power loss, switch off, then on - can act as a count reset. It is also not critical because if there is a power loss, the plan B is go out and shake the barrel.

Tell me what Arduino version, display, other components and I will get them delivered to you.

Is that practical?

As said, I'm not interested in making anything out of this and if it proves cheap enough and works well enough, I will help to try to sell it. I can cope with bare PCB's but buyers not.

My email address is good.

[Harry Bloomfield]

critcher explained on 27/04/2015 :

When she runs out of water in the middle of washing her hair, it becomes a nuclear reactor lol

With a display the decision becomes hers whether hair washing is a good idea or not.

[Chris J Dixon]

I note that it says

"... each pulse is approximately 2.25 milliliters. Note this isn't a precision sensor, and the pulse rate does vary a bit depending on the flow rate, fluid pressure and sensor orientation. It will need careful calibration if better than 10% precision is required."

So, to allow a little in hand, you will want to sound the alarm at about 20% left, which could be 30%.

I think I will stick with manual methods and dead reckoning.

They quote a minimum life of 300,000 cycles, but I'm not sure what they count as a cycle - presumably not a pulse, since that would only be equivalent to 666 litres.

Chris

[Harry Bloomfield]

Tim Watts explained :

Back in the day, I did m/c code, Assembler, C, C+, a bit of Fortran and a lot of Basic - but all that was 30+ years ago, when things were so much simpler.

[Harry Bloomfield]

Its a matter of suck it and see. I make 750 litres, but that is a minimum life, mean will be much higher, it intended for much more intensive use than a caravan would put it to.

The spec. I read was this, which quotes +/- 2% accuracy. The accuracy will deteriorate with very low flow rates, but you usually turn caravan taps on full flow anyway.

Model:YF-S201 Sensor Type: Hall effect Working Voltage: 5 to 18V DC Max current draw: 15mA @ 5V Output Type: 5V TTL Working Flow Rate: 1 to 30 Liters/Minute Working Temperature range: -25 to 80? Working Humidity Range: 35%-80% RH Accuracy: ±2% Flow Range: 1-30L/min Detecting mode : Vertical Maximum water pressure: 2.0 MPa Output duty cycle: 50% +-10% Output rise time: 0.04us Output fall time: 0.18us Flow rate pulse characteristics: Frequency (Hz) = 7.5 * Flow rate (L/min) Pulses per Liter: 450 Durability: minimum 300,000 cycles Cable length: 15cm 1/2" nominal pipe connections, 0.78" outer diameter, 1/2" of thread Size: 2.5" x 1.4" x 1.4"

[Fredxxx]

I would have said things have either not changed or in many cases got easier.

There are many examples of anything you want to do on the 'net such that you're never stuck for long.

I have focussed on ARM micros, and there are a few open source IDEs that cater for this range.

PICs are a little more esoteric.

[Tim Watts]

Then you'll like the Atmel AVR.

The C is pure and the headers mean all the IO ports and timers and stuff have all the #defines done nicely.

AVR Studio is a free dev workbench with a software emulator and debugger that can emulate all the chips.

They are a Harvard architecture (separate program and data address spaces) but that doesn't make much difference to programming, except you cannot execute off the stack.

Believe me, it is 1000 times easier than trying to program a GUI under Windows or Linux - I think you will actually like it.

You could start "lite" and write the whole thing as a loop in main().

But a better way will be to tie your sensor input to a hardware interrupt which IIRC can be tied to a hardware counter. In either case, just sleep the CPU, then it will re-awake on a pulse, you update counters and display outputs then sleep again.

[Simon Brown]

That sensor isn't going to be that easy to get into his drum.

[Mike Barnes]

OK, how about one of these (or similar):

To stay within the spirit of the group, you could fit it yourself.

[Fredxxx]

Wouldn't one of these do?

Take note of reading when full, predict when empty?

[Simon Brown]

Not so convenient when moving it to fill it. Too hard to put it on the spring balance when full.

Yes, you could organise some sort of crane thing but his flow meter approach is MUCH simpler.

[Simon Brown]

He appears to keep the barrel outside, so that isn't really very practical.

[Theo Markettos]

That's why I wouldn't touch a PIC - they're too 1990s, and not in a good way. There are newer PICs, but something like Arduino has a much lower barrier to entry. You can just cobble together code that other people have written - there are tons of libraries for the parts you might want. It's probably a couple of screens at most, would take a few hours if you have all the libraries and there's no showstoppers. Arduino's designed for teaching kids, so programming 30 years ago sounds like you're overqualified ;-)

Just download the Arduino software and have a play, you don't even need to spend a fiver on a board to give it a go (though you obviously won't be able to test your code).

But this is a DIY group. Asking someone to do all your work for you for nothing just isn't cricket.

Theo

[Harry Bloomfield]

Now that, might just work, it might provide a restriction in the pipe / flow though. Well worth considering though, if I checked the difference a 1/4" restriction would make to the flow rate.

[Capitol]

Yes, done it for years.

[Capitol]

It's dead easy, the wires just pop in through the window, the window seal will not notice the wire thickness.

[Capitol]

I've told you how to do it, see what she says?

[Simon Brown]

The problem isn't the wires, it's weather proof scales that work well out in the dirt next to the van. That isn't going to be anything like as cheap as his approach.

And not practical either with a barrel that is carted around to fill it.

[Chris J Dixon]

What, from 300,000/450 ?

Chris

[Chris J Dixon]

Bottom end appears to be 500 litres, when you are looking for