This version includes several critical corrections and minor layout improvements over V1.0:
✅ Fixes:
- Replaced C10 from Aluminum to Tantalum capacitor as originally intended.
- Replaced U4 regulator with a 5V output model (was mistakenly 3.3V in V1.0).
- Corrected C9 value in the schematic from 10pF to 10nF to meet design spec.
🛠️ Layout Changes:
- 5V source routing was corrected: now the 5V supply is taken from the output of selector JP1, not directly from the 5V regulator output.
- D3 LED signal line re-routed: in the previous version, D3 was incorrectly connected after R3, which caused a voltage drop affecting the signal level. As a result, the CH340 USB-to-serial module failed to receive data sent from the microcontroller. This issue has now been resolved.
🧱 Minor Layout Adjustments
- Changed orientation of R7, R12, R13 from horizontal to vertical for better routing and readability.
⚙️ These updates improve component accuracy, circuit reliability, and board manufacturability.