CHANGE LOG V3.0:
- COS and Inverted COS added
- Basic components changed to 0603 package for availibility.
- TLP241-4 replaced by 4x 817 optocoupler for cheaper cost and availibility.
- Micro USB replaced with Mini USB port for easy soldering and availibility.
Detail: https://s21rc.net/s21rc-digital-interface-rev-3-0-ham-radio-computer/