This new version adds upper sideband so that now the BITX40 can be used for digital modes on 40m. Note that you must use the si5351 v2.0.1 library with the Arduino IDE for it to compile. You must also add a "Function" pushbutton to access all of the new features, which are listed as:
Added functionality via the Function Button
- Use a pushbutton to momentarily ground pin A3 (orange wire). Do NOT install an external pull-up resistor!
- dual VFO A/B capability (RIT is not yet working though)
- LSB/USB mode selection
- Settings menu for calibration, tuning range, VFO drive level
- All settings are stored in EEPROM and read during startup
Here is a picture of the BITX40 receiving WSPR on 7038.6 KHz USB. I am using the software WSJT-X for both modes.