Shower Timer

[Emmo]

Hi All,

Im building a shower timer because the kids are spending way too long in the shower. I want to use a picaxe chip. I will program it to a timer start when the water starts to flow (Water Flow Sensor) count 5 minutes and then shut the water off using a solenoid valve.

Im just wondering can anyone advise what water flow sensor I can use and how to interface it with the micro controller. Also will I have to use a relay to control the solenoid? One more question: What actual picaxe micro controller will I use?

This project will be perfectly safe: I will incase the picaxe in a waterproof case in the bathroom and my brother is an electrician so I will have him do all mains wiring.

Thanks in Advance,
Emmet

 

[Buzby]

... what water flow sensor I can use ...

I used a temperature sensor strapped to the hot water pipe. No need for any plumbing, and cheap.

 

[SAborn]

It might pay to just shut the hot water off by the solenoid, this will get the message across real fast and also remind them to close the taps off afterwards.

Yes i would use a relay, although it could be a mosfet or transistor, but as its a simple on/off switching and only at periodic intervals a relay should work fine.

You may be able to use a solenoid from a washing machine, best to use the hot water solenoid.

 

[erco]

Two great suggestions already! I had a condensation problem in a bathroom, folks just weren't turning on the exhaust fan. I put a thermistor on the hot water supply line (as Buzby suggested) with a comparator (with hysteresis) adjusted to trigger a relay when the pipe was hot. It turned on instantly and stayed on for an appropriate time after the shower was turned off, to keep venting for a while. I wired the relay in parallel with the wall switch, so manual operation is still possible. Now everyone's happy.

 

[premelec]

Reminds me of coin operated showers I've come across when travelling at camp grounds... could be a money maker...

 

[Buzby]

... You may be able to use a solenoid from a washing machine, best to use the hot water solenoid ...

The washing machine solenoid valve is normally shut, and needs to be energised to open.

If you are going to detect the shower usage by monitoring the flow, then the solenoid will need to be energised for all the many hours that the shower is not being used, otherwise there will be no flow to detect the start of a shower. You will use more energy by powering the valve 23.5/7/365, and a washing machine valve might not be rated for extended powering, as it's normally only energised for a few minutes as the drum fills.

Either use an 'energise to shut' solenoid valve, or decide on another method of detecting a shower. Maybe just a button labelled 'Press for Shower'.

 

[inglewoodpete]

The shower timer need not be so intrusive with your existing plumbing and electrics.

A battery operated box with a PICAXE and a LOUD peizo sounder and a temperature sensor attached to the hot water pipe. Possibly a reset button (in a different room if necessary) so that more than one person can have showers in sequence. (Otherwise, the successive people have cold showers...)

 

[Emmo]

I used a temperature sensor strapped to the hot water pipe. No need for any plumbing, and cheap.

What a fantastic idea, never thought of it. Will be a lot easier and cheaper to do than using a water flow sensor. Thanks Buzby!

It might pay to just shut the hot water off by the solenoid, this will get the message across real fast and also remind them to close the taps off afterwards.

Another fantastic idea, I will definitely be only shutting off the hot water by the solenoid or else they would just leave the shower on when their time is up and waste even more water.

Yes i would use a relay, although it could be a mosfet or transistor, but as its a simple on/off switching and only at periodic intervals a relay should work fine.

Grand, I will use a relay so. Will I just use a solid state relay?

Reminds me of coin operated showers I've come across when travelling at camp grounds... could be a money maker...

Im liking your thinking premelec ! haha

The washing machine solenoid valve is normally shut, and needs to be energised to open.

If you are going to detect the shower usage by monitoring the flow, then the solenoid will need to be energised for all the many hours that the shower is not being used, otherwise there will be no flow to detect the start of a shower. You will use more energy by powering the valve 23.5/7/365, and a washing machine valve might not be rated for extended powering, as it's normally only energised for a few minutes as the drum fills.

Either use an 'energise to shut' solenoid valve, or decide on another method of detecting a shower. Maybe just a button labelled 'Press for Shower'.

All very good points, that I didnt even think about when using a washing machine valve, I think an energize to shut valve is the best way to go. Thanks again Buzby!

The shower timer need not be so intrusive with your existing plumbing and electrics.

A battery operated box with a PICAXE and a LOUD peizo sounder and a temperature sensor attached to the hot water pipe. Possibly a reset button (in a different room if necessary) so that more than one person can have showers in sequence. (Otherwise, the successive people have cold showers...)

The problem with this is that no matter how loud the alarm is, my kids will just ignore it and continue on using hot water to their heart contents. The only way to stop them is to shut the water off.

 

[Hemi345]

How many kids and do they shower in succession AFTER you take your shower? Turn the temperature down on the hot water heater. You still might have one kid use what's left of the hot water, but the others will take a really short shower since it'll be cold. haha

 

[Emmo]

How many kids and do they shower in succession AFTER you take your shower? Turn the temperature down on the hot water heater. You still might have one kid use what's left of the hot water, but the others will take a really short shower since it'll be cold. haha

3 kids, they have their showers at night and my wife and I have ours in the morning before work.

 

[Buzby]

... I think an energize to shut valve is the best way to go ...

An alternative to a solenoid valve is a motorised valve, as used in central heating systems. Just Google 'wiring motorised valve'.

Or see : http://wiki.diyfaq.org.uk/index.php?title=Motorised_Valves

Cheers,

Buzby

 

[eclectic]

3 kids, they have their showers at night and my wife and I have ours in the morning before work.

In that case, a "parent alert" alarm.

Then Mom or Dad can physically turn off the water,
or eject the occupant.

e

 

[hippy]

Rather than turn the water off you could consider turning the lights off.

I'd probably choose a klaxton or loud piezo as the most persuasive conditioning long-term and involves least effort and complexity. There will be blazing rows and resentment if the water cuts off while someone is soaped-up.

 

[Emmo]

An alternative to a solenoid valve is a motorised valve, as used in central heating systems. Just Google 'wiring motorised valve'.

Or see : http://wiki.diyfaq.org.uk/index.php?title=Motorised_Valves

Cheers,

Buzby

Thanks Buzby I will look into these, but what exactly are their advantages over solenoids?

In that case, a "parent alert" alarm.

Then Mom or Dad can physically turn off the water,
or eject the occupant.

No eclectic, this wouldn't work for me as I am not there sometimes in the evening when the kids are having showers and my wife couldn't give a toss about how long they spend in the shower and how much it will cost.

Rather than turn the water off you could consider turning the lights off.

I'd probably choose a klaxton or loud piezo as the most persuasive conditioning long-term and involves least effort and complexity. There will be blazing rows and resentment if the water cuts off while someone is soaped-up.

Good Points, hippy and I will use a loud piezo to inform the kids that time is nearly up.

 

[Paix]

I think that the Claxton accompanied with the lights out for effect and to combat the possibility of the occupant being freshly soaped up at the time continue the cold water.

On the basis that this is, sooner or later going to catch your wife instead of the kids, are you going to have a divorce party and are forum members invited?

 

[mark.duyvesteyn]

i did this with our continuous hot water system. When the hot water turned on, a LED on the control panel in the bathroom went high. I used this input to start a timer. When the 7 minutes was up, the shower hot water would turn off and would not turn back on for 3 minutes. I used a relay across the button on the controller to turn the hot water off.

 

[erco]

I bet many electric solenoid water valves are neither rated nor suitable for hot water. Better make sure you check that out.

 

[inglewoodpete]

I bet many electric solenoid water valves are neither rated nor suitable for hot water. Better make sure you check that out.

Probably true but most (clothes) washing machines and many dishwashers have hot water values.

As I've said previously, I'm not in favour of adding control valves. I'm sure a loud and annoying piezo will gradually get kids to modify their behaviour. Otherwise, connect your vacuum cleaner to the alarm: that's something that seems to upset kids more than anything else!

 

[SAborn]

Im not sure why with using hot water washing machine solenoids became a problem, a standard solenoid is normally closed with no power applied, so the solenoid is only drawing power when the valve is open (HW on).

I agree with IWP with using temp control, but would do it using a bypass stricter to control HW flow.
Simply in the plumbing in parallel to the solenoid valve, you also have a tap/valve that you can reduce the flow of HW on, this is set to only permit a low lukewarm shower, just bearable above cold water, or a dribble if adjusted by cold water to increase water temp.

The solenoid only bypasses the restrictor and allows full flow of HW for the controlled period.
Lets face it when showering and to drop from about 30+C water temp to 20+C temp is quite a shock that dont inspire you to want to hang around, although 20+C water is still suitable to rinse the last few suds off and bail out.

you could use IR remote as a Adult control to override the system.

Using a delay time like Mark of 3 minutes., this should allow for enough time to permit the sensor to cool down enough to detect the next shower cycle.

For adult operation allow 20 mins for the cycle, surely thats enough time for the cookie cutter to pluck, shave, shampoo, condition, comb through 10 times, lather and wash every square inch of the body 5 times over, and distress from the day.

I think its a very good project, as its educating your kids on saving resources.
Fresh water is the number 1 resource we take for granted and waste in mass amounts, i feel its the main thing needing to be addressed to save the planet, we often dont even use fresh water once and let it run down the drain because its cold or we are not ready, or pee out 500ml and use 3-6 liters of fresh water to flush it away.
We coat the planet in hard surfaces like house roofs and pavement, then catch all the fresh water and pipe it out to sea.

And, and, and, ................But here is not the place to discuss these issues, except to say education of the next generation to conserve water is a excellent thing in my view.

 

[Ravenous]

Are these the same beloved kids who will be looking after you in your old age? I suggest you think carefully about this...

I knew a bloke who was ex-navy and told me of the alleged Navy Showers. You get one minute of water to get wet, then as long as you like in there to soap the bits you care about, then one minute (with water again) to get all the soap off again

 

[Buzby]

... I agree with IWP with using temp control, but would do it using a bypass stricter to control HW flow.
Simply in the plumbing in parallel to the solenoid valve, you also have a tap/valve that you can reduce the flow of HW on, this is set to only permit a low lukewarm shower,

Another solution would be to use a 3-port motorised valve, which could change the hot shower pipe to the cold supply, thus giving the shower two cold pipes.

By driving the valve slowly, the maximum availalable temperature could be gradually reduced.

 

[SAborn]

Very true, but im a little cheaper than that and also like using proven recycled parts for next to nothing, also see little point in making the shower totally cold and unbearable where just uncomfortable is all that is required.

 

[Emmo]

I think that the Claxton accompanied with the lights out for effect and to combat the possibility of the occupant being freshly soaped up at the time continue the cold water.

On the basis that this is, sooner or later going to catch your wife instead of the kids, are you going to have a divorce party and are forum members invited?

The problem with turning the lights out is, it will be dark when the kids have their showers, so if the lights go out and they are still in the shower, I don't want them breaking their necks trying to get out of the shower in the dark.

i did this with our continuous hot water system. When the hot water turned on, a LED on the control panel in the bathroom went high. I used this input to start a timer. When the 7 minutes was up, the shower hot water would turn off and would not turn back on for 3 minutes. I used a relay across the button on the controller to turn the hot water off.

Good info to note, thanks mark.

Probably true but most (clothes) washing machines and many dishwashers have hot water values.

As I've said previously, I'm not in favour of adding control valves. I'm sure a loud and annoying piezo will gradually get kids to modify their behaviour. Otherwise, connect your vacuum cleaner to the alarm: that's something that seems to upset kids more than anything else!

Pete, I really don't think a piezo, no matter how loud it is gonna work, because no matter how many times I shout at the door of the bathroom they stay in the shower letting money go down the drain. So if i can't get them out, I really don't think a little box on the wall making an annoying noise is gonna get them out.

Im not sure why with using hot water washing machine solenoids became a problem, a standard solenoid is normally closed with no power applied, so the solenoid is only drawing power when the valve is open (HW on).

I agree with IWP with using temp control, but would do it using a bypass stricter to control HW flow.
Simply in the plumbing in parallel to the solenoid valve, you also have a tap/valve that you can reduce the flow of HW on, this is set to only permit a low lukewarm shower, just bearable above cold water, or a dribble if adjusted by cold water to increase water temp.

The solenoid only bypasses the restrictor and allows full flow of HW for the controlled period.
Lets face it when showering and to drop from about 30+C water temp to 20+C temp is quite a shock that dont inspire you to want to hang around, although 20+C water is still suitable to rinse the last few suds off and bail out.

you could use IR remote as a Adult control to override the system.

Using a delay time like Mark of 3 minutes., this should allow for enough time to permit the sensor to cool down enough to detect the next shower cycle.

For adult operation allow 20 mins for the cycle, surely thats enough time for the cookie cutter to pluck, shave, shampoo, condition, comb through 10 times, lather and wash every square inch of the body 5 times over, and distress from the day.

I think its a very good project, as its educating your kids on saving resources.
Fresh water is the number 1 resource we take for granted and waste in mass amounts, i feel its the main thing needing to be addressed to save the planet, we often dont even use fresh water once and let it run down the drain because its cold or we are not ready, or pee out 500ml and use 3-6 liters of fresh water to flush it away.
We coat the planet in hard surfaces like house roofs and pavement, then catch all the fresh water and pipe it out to sea.

And, and, and, ................But here is not the place to discuss these issues, except to say education of the next generation to conserve water is a excellent thing in my view.

The problem with using washing machine solenoids is that, the solenoid I want to use will be normally open, so when they turn the shower on hot water will flow through the pipe heat up the thermistor and start the timer, when time is up I want to shut the hot water valve for 3 minutes, thus applying power to the solenoid to close it. After 3 minutes I will remove power from the solenoid and let hot water flow again so the next kid can have their shower.

Good idea with the restrictor, I will incorporate it into the system.

I was going to use an ibutton the override the system on the control panel outside the bathroom door. My wife and I will have ibuttons on our keys which we will touch again the reader. This will disable the whole system for 20 mins or so and then reactivate so we don't need to reactivate the system ourselves. What do you think of that idea?

Haha its nice to see someone in support of it, lots are saying to me whats the point but I can see this as a big money saver for us which is always good

 

[raits999]

This is a nice idea and gave me a lot of thinking about as i have 4 children.
I would make this count water quantity and not time. For quantity counting i would use cheap water meter that is easily hackable for getting output 1 or even 0,1 liters.
As it is for shower you can use normally closed solenoid and children have their own i-button to activate the system, and you can even add light sensor to turn system off when light is off.

 

[SAborn]

The advantage with using a tap as a bypass restrictor is if the circuit or solenoid/valve ever fails you can just open the restrictor tap fully and have normal use of the shower while the fault is repaired.

Nothing worst than a failure that renders the entire shower non functional for days.

 

[Hemi345]

The problem with turning the lights out is, it will be dark when the kids have their showers, so if the lights go out and they are still in the shower, I don't want them breaking their necks trying to get out of the shower in the dark.

Good info to note, thanks mark.

Pete, I really don't think a piezo, no matter how loud it is gonna work, because no matter how many times I shout at the door of the bathroom they stay in the shower letting money go down the drain. So if i can't get them out, I really don't think a little box on the wall making an annoying noise is gonna get them out.

The problem with using washing machine solenoids is that, the solenoid I want to use will be normally open, so when they turn the shower on hot water will flow through the pipe heat up the thermistor and start the timer, when time is up I want to shut the hot water valve for 3 minutes, thus applying power to the solenoid to close it. After 3 minutes I will remove power from the solenoid and let hot water flow again so the next kid can have their shower.

Good idea with the restrictor, I will incorporate it into the system.

I was going to use an ibutton the override the system on the control panel outside the bathroom door. My wife and I will have ibuttons on our keys which we will touch again the reader. This will disable the whole system for 20 mins or so and then reactivate so we don't need to reactivate the system ourselves. What do you think of that idea?

Haha its nice to see someone in support of it, lots are saying to me whats the point but I can see this as a big money saver for us which is always good

Since you say you'll have an iButton for you and the misses, then make one up for the kids too. Have it tethered near the box so they won't lose it. That frees up your options on valves and you could use a simple normally-closed valve like washing machine or maybe even irrigation (the specs on the Rainbird models I use say they'll handle 110F/43C water).

When anyone scans the ibutton, then the valve opens for 5 minutes (and an indicator light comes on). Once the thermistor on the hot water line detects heat (that they're actually in the shower), the valve timer restarts with either the child or parent allowable time. If no heat detected during that initial 5 minutes, the valve turns back off along with the indicator light.

Use the indicator light so you know if the hot water valve is open or closed. If they scan the ibutton, then take their time (getting undressed/flexing in the mirror haha) and the 5 minutes times out, they'll have some indication on why they're not getting any hot water. If the light is viewable while in the shower (through the shower door/curtain) then you could even flash it for 30 seconds before it shuts the valve off to warn them.

 

[Emmo]

Since you say you'll have an iButton for you and the misses, then make one up for the kids too. Have it tethered near the box so they won't lose it. That frees up your options on valves and you could use a simple normally-closed valve like washing machine or maybe even irrigation (the specs on the Rainbird models I use say they'll handle 110F/43C water).

Never thought of having another iButton for everyone, what a great idea, good idea to tether it near the controller as well, cause my kids will lose anything and it will make the whole valve thing so much easier.

When anyone scans the ibutton, then the valve opens for 5 minutes (and an indicator light comes on). Once the thermistor on the hot water line detects heat (that they're actually in the shower), the valve timer restarts with either the child or parent allowable time. If no heat detected during that initial 5 minutes, the valve turns back off along with the indicator light.

Use the indicator light so you know if the hot water valve is open or closed. If they scan the ibutton, then take their time (getting undressed/flexing in the mirror haha) and the 5 minutes times out, they'll have some indication on why they're not getting any hot water. If the light is viewable while in the shower (through the shower door/curtain) then you could even flash it for 30 seconds before it shuts the valve off to warn them.

Great way to program the system, I am going to use this exact idea to program my system.

Thank you for your helpful and make my life so much easier advice!

 

[Marcwolf]

How about this system. Button opens solenoid. Temp sensor on pipe waits for water to warm up before starting timer (can be overridden by parent). 4 min 30sec timer will pulse solenoid twice to warn that 30secs remains. 5 mins solenoid shuts stopping hot water. Timer then waits another 5 mins to reset function, as pipe should still be hot there is no need for timer to delay start for hot water to flow. Sorry - I cannot use CR/LF at moment so all one line. Marc

 

[hippy]

Never thought of having another iButton for everyone, what a great idea, good idea to tether it near the controller as well, cause my kids will lose anything and it will make the whole valve thing so much easier.

Or simply go for a button or, even better, something which can detect shower occupancy or, best of all, a flow detector so you can tell when the shower is started. That way there's default operation without needing anything at all and you only need to use the parent keys when you want more than default yourself. The least intrusive automation is the better you will find it.

 

[Emmo]

Hi Guys,

Im thinking the ibutton for everyone is the best way to go.

Or simply go for a button or, even better, something which can detect shower occupancy or, best of all, a flow detector so you can tell when the shower is started. That way there's default operation without needing anything at all and you only need to use the parent keys when you want more than default yourself. The least intrusive automation is the better you will find it.

The ibuttons will really be no hassle and the kids will have fun scanning theirs for their shower. I don't think it will intrude too much on their showers.

Right now, I need some advice on programming this whole thing (its not really my strong point). Do I need to have a switch to press before you scan an ibutton or can it just be constantly looking for ibuttons? Can I lock out an ibutton which has been scanned already for a period of time say an hour or so. Any other advice on programming it?

Thanks again for all your help and inputs!