Arduino U8 Replacement Board

Ok. I finally just sat down and did it. I was never happy with the fact that my final watches were not in professional cases and didn't have good interfaces. So, with the U8 watch down around the $10 level, it was time to replace the inner board with a drop in replacement Atmel mega32u4 Arduino compatible board.

From the original U8 watch, I reuse the following:
1) The case and all the buttons and ports
2) The Touchscreen LCD (both LCD and touch controller)
3) The vibrating motor
4) The speaker
5) The battery
6) The reset button

Really, the old board comes out, and the new board goes in. Click below to download the Eagle schematic and board files.

Arduino U8 Arduino Watch Board

If you want to reproduce this project I highly recommend spending some time re-routing the board. The components are in a good position, but the board is messy.

The above is the completed unit running a very basic operating system.
Here is the U8 watch open up.

After disassembly, you are left with the following:

Now the goal is to carefully un-solder the add-ons to the board. Be especially careful with the LCD. It is connected with a flexible pcb and if you lift up on it when the solder is not molten, you can easily break off contacts.

Start soldering the bare board. Initially, put on the components needed to run the Arduino. You are going to program it through the SPI which is brought out on the LCD pins on the pc board as well as a pad labeled MISO.

Use a programmer (or another Arduino set up to program a bootloader) and load the Leonardo or other 32u4 based bootloader.

Once you confirn the Arduino operation (You should be able to communicate over the USB port) finish assembling the rest of the board.

Drop this board into place and insert the touchscreen flexible cable to the connector on the board. Solder the reset switch, speaker, and vibration motor. Finish by soldering the battery. Plug in the watch to charge the battery.

Below is the sketch I used in the demo. Like I said, it is pretty raw so you will want to make this watch your own.

Arduino U8 Watch Sketch

You can do a search for the libraries if you need to.

That's it. If you have any interest in doing this, know that there are many aspects of the project that are difficult so this is not for the faint at heart. For the more advanced of you, you could probably find a way to add bluetooth. Or even replace the 32u4 with an ESP8266 and have wifi access. 

Please visit my new company. I am creating Science, Technology, Engineering, and Math education modules and curriculum. I have a bunch of free resources too.

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Thanks for viewing!!