Version V1.1 – Issue Fixes & Improved Routing

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.

Version V1.0 – First Tested Prototype

This is the first hardware revision that was successfully assembled and tested. The core functionality worked well, but several important corrections were identified during validation:

• R3 value must be less than 100Ω for proper LED operation.
• U4 regulator must output 5V instead of 3.3V.
• C9 should be 10nF (not 10pF as initially set).

Despite these issues, the board powered up correctly and all major functionalities were verified. This version served as the base for the updated V1.1 release.