Prototyping new ideas can be a lot of fun, but putting new projects in a durable enclosure can be a difficulty. This is especially the case when the user of this product is one of the most destructive forces in nature: A toddler! This is the circumstance that [blue blade] found himself in when he wanted to build a durable MP3 player for his grandson, and you can see the results of his work below the break.
The hardware is simple: A 16850 lithium-ion battery powers an MP3 Decoder/Amplifier module that plays MP3s stored on a Micro SD card. A speaker, power switch, and micro USB powered battery charger complete the build. What stands out most is the enclosure. Why?
When children are involved, durability isn’t a matter of product lifetime, it’s also a matter of safety. Items that are easily broken aren’t just useless, they can be dangerous. With this in mind, [blue blade] built a brightly colored enclosure with extra thick walls joined by metal bolts. Externally, a rounded cover bolts over the charger connector and Micro SD card slot. The only other protrusion is a lighted rocker switch for powering the MP3 player on and off.
The attention to durability also extends to the interior of the MP3 cube. Cutouts for the electronics keep them from moving horizontally, while a clip bolts over them to keep them firmly planted. Zip ties hold the battery to the base, and hot glue provides an extra element of security to the circuit boards. Even the speaker is held firmly in place by four bolts. [blue blade] has made the print available with a Creative Commons license.
What’s more, [blue blade] reports that his grandson loves the toy, and that the cube has withstood over six months of toddler abuse. Clearly, the attention to details given this toy has made it nearly indestructible!
If kid proof printsheck out this toddler friendly MP3 player with light based navigation, and this Ikea book shelf turned into a buttonless MP3 player. And of course if you have any interesting hacks to share, be sure to send them our way via the Tip Line!
Looks like a DIY toniebox. Im not sure if the article states, but is the outside also soft and of cloth?
Makes me think of the 3D printable Google/RaspPi AIY case from a few years ago.
https://www.thingiverse.com/thing:2305359
Nice project!
We did something similar in 2017, just with RFID to chose the playlist:
https://hackaday.io/project/26293-put-n-play-cube
Survived 2 Toddlers so far without problems ;-)
Survived 6 months of toddler?! Impressive.
I’m surprised no mention is made of protection against liquid ingress, as that’s a common issue for toddler toys. A sippy cup emptied over a battery is not a happy battery.
Once the kids get a bit older (>=2y) they prefered this one, 8 playlists choosable via colored buttons:
https://der-frickler.net/_media/technik/musicbox/musicbox_004.jpg
Last revision automatically powers off after use and has a custom pcb for easy building
https://der-frickler.net/_media/technik/musicbox/musicbox_001.jpg
I suggest wireless charging.
This seems very well thought out and pretty durable but…
*I second wireless charging (and perhaps wireless interface) – anything that has to be frequently unscrewed and plugged in isn’t a great idea.
*Covering any and all speaker grilles etc. with impermeable material (because boy is stuff gonna permeate).
Definite downcheck: the switch. That’s going to die an early and ugly death. Good to 300,000 cycles you say? Okay, you’ll see that’s now called “By next Thursday unless liquids are involved, in which case it’s 3:00 this afternoon”.
If you substitute a sealed pushbutton, be sure to test it by putting a weight on it until the battery has run completely flat just to see what might catch fire.
TL;DR: Toddlers are the best tests to destruction ever.
All consumer electronics, before being generally released, should be given to groups of toddlers and 80 year olds. If the seniors can use them and the toddlers don’t destroy them they are ready for release.
The story goes, that before IBM released the original IBM PC to the public, they went to get a “man off the street” opinion. Something like 50 non computing people were brought in one by one,, and set down in front of one with its glowing green A:> prompt.
One of the subjects typed in; “What is the capital of Alaska?”