“A simple Kitchen timer with an Internet Alarm Clock built inside a power brick.
A few years back, fellow Hackster Juraj published a Kitchen timer and clock which he built into a power brick. I liked this concept so I thought I would take this concept and apply a few improvements to it.
The power brick
The hardest part of this build if finding a suitable power brick. Looking through my box of power bricks I came across one that contained a simple transformer design rather than the more common switched mode power supply.
As the image shows, the bottom and top parts of the case were held together with four screws. Rather than drill and mill the top part to fit the components as Juraj did in his build, I decided to design and 3D print a top so that I could screw my PCB in place and not rely on glue.
3D Printing
The STL files are attached. You can slice them with your slicing software or take them to be printed at a commercial 3D print shop.
“Timer - Box.stl” - 0.2mm layer height, no supports
“Timer - Clips.stl” - 0.2mm layer height, no supports
“Timer - Display.stl” - 0.1mm layer height, no supports
“Timer - Knob.stl” - 0.1mm layer height, no supports
Schematic
The CPU is an ESP32. Being WiFi enabled, the clock obtains its time over the Internet from a time server. To improve the sounds that can be played, a DF mini MP3 player module is also included. This module requires a micro SD card and you will need to unzip the attached “mp3.zip” onto this SD card.
Assembly
The Eagle files have been included should you wish to get the board commercially made or you can make it yourself. I used the Toner method to make mine.
Add the links if your board is single sided.
Next add the headers. If your board has through hole plating, you can solder the wires directly to the board rather than use a connector. If you use a header on a single sided board, here is the method I use to add them.”