Do you experience "programming port disappear" problem? Please read it and try to recover.
The movie below shows the initial ULTIMA,,,,and
The improved ULTIMA for tindie.com release version is improved with I2C and SPI but pinout, which is introduced in the following movie....
Utilising I2C interface, bouncing ball by its tilt is quickly made as following movie!
Its source code is uploaded to github. Have fun!
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