Introduction: Desk Organizer With LED Matrix Clock and Bluetooth

My desk was very cluttered and I wanted to have a nice organizer where I could arrange my pencils, paint brushes, clay tools etc. I looked at many organizers in market but did not like any of them. I set out to design my own desk organizer and here is the result.


DS1307 RTC Module

HC06 Bluetooth Module

Arduino Nano


MAX7219 LED Matrix Module

Clear Epoxy Resin

Wood Glue

4 MM Plywood

Cellphone charger


Step 1: Idea

This is my plan for the desk organizer. I decided to make it out of 4 MM plywood. It is easy to cut with a utility knife. Next steps detail the construction process of the organizer.

Step 2: Constructing the Front Panel

I measured the LED Matrix and designed front panel based on that. After cutting out window for LED Matrix, I covered the cut out wood piece with clear tape and pushed it again in cut window. Added thickness of clear tape helped to friction fit wood piece to the window. I ensured to leave a small recess while fitting this piece. I painted outer panel of this window black. Then I placed this whole panel on flat surface. I mixed 2 part clear epoxy and added few drops of brown tint in the resin. I poured this resin on front window panel. Then I sprinkled some golden glitter very sparingly on this panel while epoxy was setting. After Epoxy resin cured, I removed the wood piece. This gave a clear window to show LED Matrix through. Also from the front it appears seamless.

Step 3: Constructing the Organizer

Next step is to construct the organizer. I started cutting panels and gluing them with wood glue. Once completed, I poured colored epoxy resin on all sides to get a glass finish.

Step 4: Faux Triode (Vacuum Tube)

I wanted to give my desk organizer some steampunk touch by adding 2 faux Triodes (tube amps). For making the triodes, I created a mold using a bottle of alcohol ink and a plastic lens lying around. For mold making I used Amazing mold putty.

I created grid for the triode using stapler pins and some colored aluminium wire. I added an amber LED for glow of the heating filament. At the base of this setup I added a card stock disc. Sadly I dont have pictures of the process of creating this triode. Let me know if you need detailed steps, I will add!

I poured the mold about 4/5 with clear epoxy resin. I then inserted this setup of stapler pins, LED in resin and let it set for 24 hours.

After 24 hours I de-molded triode and using silver marker painted top part of the triode to mimic the 'Getter' part of triode.

I then dipped the triode in epoxy resin and suspended it upside down. This has two benefits.

1) It makes outer surface of triode smooth and shiny.

2) a drop of resin freezes on top of the triode which replicates glass seal on real triodes.

Step 5: Circuit and Code

Circuit consists of Arduino Nano connected with DS1307 real time clock. I added a HC-06 Bluetooth module for controlling desk organizer clock from cellphone. I have added a LDR as well to control display intensity based on ambient light.

There is also a 2 pin jumper connecting bluetooth module (HC-06) to positive rail of power. This is done to enable code upload to arduino. If HC-06 module is powered up, code does not get uploaded and the error is not that intuitive.

Desk organizer code performs following functions

- Display time (12/24 hour format - controlled over bluetooth through cellphone)

- Display day, date every 5th minute

- Change Triodes' RGB LEDs random color every 5th minute.

- Display a random animation from a set of animations every 3rd minute

- Display custom message over bluetooth through cellphone

- Set Date Time over bluetooth through cellphone

- Turn off display at 10 PM and start again at 6 AM

- From 6 AM to 6:50 AM, Triode RGB LEDs start with red color and slowly transition through amber, deep yellow, lemon yellow and then white color mimicking sun rise.

I have developed bluetooth app code using MIT APP Inventor. My app is under development so setting date time and setting 12/24 hour format is not coded yet.


Note 1

MAX72XX matrices come with different hardware type. There are 4 types configured in libraries

PAROLA_HW, ///< Use the Parola style hardware modules.

GENERIC_HW, ///< Use 'generic' style hardware modules commonly available.

ICSTATION_HW, ///< Use ICStation style hardware module.

FC16_HW ///< Use FC-16 style hardware module.

If you run a test on your matrix and see garbled display or mirror image text, try initializing to different hardware type in code. For me it worked when I selected ICSTATION_HW


Note 2

Connecting wires that originally came with my LED Matrices were very frail and flimsy. Module worked fine when I was testing it with Arduino. Next day when I hooked up the circuit again, it behaved weird. After a lot of debugging, I realized that one of the connecting wires between LED module and arduino had broken internally (inside insulation) causing an open circuit. I replaced all connecting wires and things started working fine.

Arduino Libraries used:

DS1307 RTC


Step 6: Placement of Components and Port to Allow Uploading Code

Please see attached images to see my placement of components. This is my layout. You can chose the layout that best suits your need.

Step 7: Final Product

Here is the final desk organizer up and running on my desk.