Arduino Bluetooth Clock

In this instructable we explain our working process step by step. The end product is a timer designed primarily for people with autism. Because the timer shows visually how much time you have left, time units can be better understood. It is also user-friendly because you can operate the timer from your mobile phone.

We are two students of the O.-L.-V. Pulhof Institute in Antwerp and this is our thesis project.

What you need:

- arduino uno or nano

- RTC ds 3231

- Led display

- Bread board

- Solderless breadboard wires

- Bluetooth extension: HC-05

- wood panel                                                                                                                                                        

- wood glue                                                                                                                                                                  

- Soldering machine and solder

Below you can find the code for this instructable.

When we received the clock module, there was no output attached to it. Therefore we used a soldering machine and solder to secure it to the clock module.   

To design the app, we used MIT App Inventor, a program that is very beginner friendly. Our app contains a way to set the timer and a way to show the actual time.

We made a casing out of wood with a thickness of 0.7 cm. The design contains 3 cutouts: one in the front for the display and 2 on the side for the cabels from the arduino and the power supply. We used wood glue to assemble the pieces together. To provide an easy way to acces the inside, we made sure to leave a way to open the top.   

below you can find the measurements we used.

All that was left to do was to put everything together. We debated using a power bank to supply our clock with power. But in the end we chose to just use a regular plug.