I made a smartwatch for only around 41$ using a TinyScreen+, a 240mA battery, and paper tape.
There are multiple apps, can be upgraded with more modules at tinycircuits.com (like a SD card for more then one app at once), and runs almost any Arduino script you can throw at it.
I call it the JMKWatch to go along with the other things I have coded in Python at jmkos.com, but the code is freely editable so you can change what yours and the apps are called, and make your own!
Step 1: Getting the Materials
The only materials I used to make this smartwatch are:
Step 2: Uploading the Code
This smartwatch can run any Arduino script that a Arduino Nano can and more, but I have made some custom Arduino scripts made for it here:
System Crash (equvalent to BSOD): https://www.dropbox.com/s/s1xbf08dfjrwnki/JMKWatch...
Also, a script made for O Watch, the clock as shown in the title image, will work on this fine, but if you get a RTC module at TinyCircuits, the time will always be in sync with the real time, being a Real Time Clock.
NOTE: The code I am linking to is not the same as the one shown in the image, due to internet 404s, but a newer, more updated script that uses the RTC module is at this link:
Step 3: Putting It All Together
Once the battery and the TinyScreen+ are ready,
- Put a tape loop or double stick tape on the watch band, then place the battery on it
- Cover the top and sides, but not the wire, of the battery with tape
- Put a tape loop or double stick tape on the top of the battery, then place the TinyScreen+ on it
- Connect the battery to the TinyScreen+
- Cover the bottom of the TinyScreen with tape
- Shield off the area next to the MicroUSB port with tape
- Done! You can now access the buttons or switch on the sides of the device and upload apps!