How to build your own Enuresis (Bedwetting) Alarm

Build what?  Yup, if you have kids you might have one or two that are getting a little older and still needs a sheet change in the morning.  If your kid is under 5 years then move along.  We are talking kids 5+ here and let me also start by disclaiming that I am not providing medical advice and am not responsible for death, injury, blah, blah... you know what I am saying.

Having said that, let me give you some brief tips that might save you the hours of research I did dispelling the myths and unknowns.

My guy is a deep sleeper.

• Wetting the bed has nothing to do with how much your kid drinks. Have your kid drink plenty in the day.
• If your kid is not wetting their pants in the day then in almost all but rare cases s/he is a deep sleeper and when their body is telling them to pee they keep snoozing.
• Medicine helps in the short term but doesn't address the long term problem: training your kid to wake when they gotta pee.
• Your kid may feel bad about wetting the bed, so let them know if they wet the bed it's no biggie (Don't let Jr. see your frustration having to change the sheets  ... keep your gripes to yourself!)

Anything beyond these points I have found to be either insignificant or even incorrect.

Why use an alarm?

Ok, so your kid's body says "Hey, I gotta pee!" but your kid just continues to happily snooze as s/he soaks the sheets.  So how do we train your kid to wake and take care of business?  Well, that is where the alarm comes in.  Here is how it works:  The second your child starts to pee the alarm detects the moisture and sounds an annoying alarm that wakes him/her up.  Remember Ivan Pavlov's dogs?  Over time (just like the dogs) when your kid needs to pee his/her body will be trained to wake up and pee. Brilliant.

If you're a cheap-o like me (Mr. Money Mustache would be proud), then once you've surfed around a bit and see that you are paying circa $100 for an alarm, you turn to your mad DIY skills and say "how can I make one of these?" Well, for less that $10 you can.  Here is how I did it...

The design

Dick Cappels has the best DIY bedwetting alarm tutorial I've found. I followed his tutorial with a few modifications of my own.

The 1N916s diodes are used to protect the 555 timers from ESD. They were a PITA to find so I ended up using 1N914s which made a good drop in replacement. The 2N2222 and 2N2907 BJTs are used as a class B amplifier to boost output of the 555 and drive the speaker.  I only like to do things once so I switched the 1M resistor for a 1M pot to adjust the sensitivity later if I needed to -- can't have any false alarms!  I also switch out the 10k pot for a 100k pot to give a little more control of the volume.

I soldered all the components on via board (bread board, proto-board, etc. work fine too).  On the scope it shows it outputs a 2.8k Hz tone which is plenty annoying to wake your little one.

Dick was genius for using the clothing snaps for the sensing leads. I keep more electrical stuff around my house than clothing snaps though so I just took a 9V battery lead and cut the connector in half.  The wires are already attached and made for a clean lead. Add some heat shrink tubing and you are golden!

There you go $100 alarm for $10.

Afterthoughts

So if you just scanned through this and are like WTF? Let me tell you, it's OK if you are tired of waking in the middle of the night to a crying kid with wet sheets and you just want something that works whether it is $10 or $1,000. I have also tried out many of the expensive alarms (Malem, Neewer, etc.).  Most of these (including the DIY solution above) your kid has to sleep with a small device clipped to his/her jammies.  This is not cool for several reasons:

1. who wants to sleep with a box clipped on their undies and 
2. your kid + tons of stuffed animals on top of a little speaker = quiet alarm.

 Hands down, the best off-the-shelf one I found is the Rodger bedwetting alarm (no, I am not getting paid for throwing their name out). There is no funny box to wear and the alarm is wireless so you stick it anywhere you want.  I recommend the back of the toilet so they have to actually walk to the toilet to turn it off.

What are your thoughts? I want to hear your bedwetting stories, solutions, etc.