Toddler nightlight/stay-in-bed device

Living with a toddler is the best thing. It really is. Seen through their eyes, everything you’re jaded about becomes new and exciting. Every piece of music is new. Frog and Toad are real people. Someone doesn’t care that you’re really, really bad at drawing, believing that you’re actually a kind of cross between Leonardo and Picasso; and you have a two-foot-tall excuse to sing Gaston at the top of your voice in public. The parents of toddlers are allowed into the ball pit at soft play. There’s lots of cake. The hugs and kisses are amazing.

frog and toad

Frog and Toad. Real people. If you are in charge of small children and do not own any of the Frog and Toad series, get yourself to a bookshop pronto. You can thank me later.

However. If my experience here is anything to go by, you may also be so tired you’re walking into things a lot. It doesn’t matter. The hugs and kisses are, like I said, amazing. And there are things you can do to mitigate that tiredness. Enter the Pi.

stay focused

I’m lucky. My toddler sleeps through. But sometimes she has an…aggravating habit of early wakefulness. After 7am I’m golden. I can do 6.30 at a push. Any earlier than that, though, and I am dead-eyed and leather-visaged for the rest of the day. It’s not a good look. Enter equally new parent Cary Ciavolella, who has engineered a solution. This is a project so simple even the most sleep-deprived parent should be able to put it together, using Pimoroni parts you can easily buy online. Cary has thoughtfully made all the code available for you so you don’t have to do anything other than build the physical object.

Pi nightlight

Cary’s nightlight can produce a number of different sorts of white noise, and changes colour from red (YOU’RE MEANT TO BE ASLEEP, KID) through orange (you can play in your room) to green (it’s time to get up). Coloured lights are a sensible option: toddlers can’t read numbers, let alone a clock face. It’s all addressable via a website, which, if you’re feeling fancy, you can set up with a favicon on your phone’s home screen so it feels like an app.

White noise – I use a little box from Amazon which plays the sound of the sea – and red-spectrum nightlights have solid research behind them if you’re trying to soothe a little one to sleep. Once you cross over into blue light, you’ll stop the pineal gland from producing melatonin, which is why I hate the fan I bought for our bedroom with a burning, fiery passion. Some smart-alec thought that putting a giant blue led on the front to demonstrate that the fan was on was a smart idea, never mind the whirling blades which are obvious to at least three of the senses. (I have never tried tasting it.)

With this in mind, I’ve one tiny alteration to make to Cary’s setup: you can permanently disable the green LED on the Pi Zero itself so that the only lights visible are the Pimoroni Blinkt – namely the ones that your little one should be looking at to figure out whether it’s time to get up yet. Just add the following to the Zero’s /boot/config.txt and reboot.

# Disable the ACT LED on the Raspberry Pi.




W. H. Heydt avatar

You get to sleep to 7 AM most of the time? I have to get up at 5:40 AM to get my grandson (age 10) off to school on time. His bus arrives at 7 AM.

Giles Read avatar

Oh, the curse of blue LEDs on bedroom gadgets! My wireless phone charger – blue LED. The ‘standby’ light on the TV? Blue. Even the damn clock resets itself to a blue backlight every time there’s a power cut.

Green light at night piques me, too.

But then, I’ve been around long enough that I’ve become a grumpy old so-and-so. A soothing red glow would have been marvelous in the nursery, years ago.

Grumpy Jeff avatar

LED’s should be red, sometimes green, sometimes amber. Never blue. And they should be dim. Blue LED’s are the scourge of our tech-laden world. Now excuse me while I chase these kids off my lawn…

Liz Upton avatar

I HATE the things. It’s handy to have some of the tiny packs of Sugru around the house: it’s lovely and opaque, and easy to mould around a (stupid blue) LED.

Mark avatar

What is with all the hatred of blue light? It is soothing and calming as opposed to the anger inducing nature of red light. I don’t understand. I know that blue light can be damaging to the eyes, but don’t stare directly into the laser-like output of blue LEDs.

me avatar

Have a look at and

“In 1958, J. Woodland Hastings and Beatrice
M. Sweeney tested the ability of different wavelengths of light—corresponding
to different colors—to shift the circadian
rhythm in the photosynthetic marine dinoflagellate Gonyaulax polyedra. The greatest power
to reset the organism’s daily meter lay in the blues,
with a precipitous decline into the greens and a
modest boost in the reds.
Hastings and Sweeney’s paper, published in
the December 1958 Biological Bulletin, gathered
dust for decades. No one thought these findings
might hold any relevance for humans, whose circadian rhythms were then widely believed to be
relatively insensitive to light.
But scientific discoveries in the past two
decades have changed all that. Not only does
light reset the human circadian rhythm, but the
same blue light that has the strongest impact on
dinoflagellates has equal power to reset our own
clocks—although most visible wavelengths can
reset the clock, the blues do the job with the
greatest efficiency”

alex eames avatar

Still got my childhood Frog and Toad books. Used to read them to Tomek.

“I cannot chase the list because chasing the list was not on my list of things to do.” (or something close to that).

Martins avatar


I didn’t use correct punctuation because I’m so angry

ameyring avatar

I made a similar device using an Arduino (before the Pi took over my life) and it helped the kids stay in bed. Eventually they hated it and were about to throw it out and so I saved it to reuse the electronics. It’s a great project to make. Teaches you timing, ensuring LEDs are bright enough with the right combination of resistors, and some woodworking.

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