WS85 uart modification - Breezedude/breezedudeWindSensor GitHub Wiki

The WS85 can be modified to output the measurement data via UART as compact binary data with CRC. This mode was added on request by Ecowitt (big thanks).

  1. Open the top cover by turning it counter-clockwise
  2. Remove the 4 screws to take off the upper plastic frame. This allows us to have more space and don't burn the plastic when soldering. If you are careful you can keep the FPC cable connected.
  3. remove resistors R2 and R3 to disconnect the power of the internal RF unit
  4. Close solderjumper J2 and J3, keep J4 open. This enables UART mode.
  5. Add a wire from pad1 to pad 7 of U2. Add a wire from pad 4 to pad 6 of U2.
  6. Open the lower part of the sensor by removing the 4 screws from the bottom.
  7. Connect the UART TX (TX of sensor, white wire) to the second pin of J8. Connect the UART RX (RX of sensor, yellow wire) to the third pin of J8. To supply the sensor with external 3.3V connect to positive (green wire) and negative (brown wire) of the battery holder.
  8. Crimp JST-PH terminal like shown in the picture
  9. Flash Firmware 1.1.6 or newer to the WS85. See Ecowitt manual & tools
  10. Test the UART output of the sensor. You may use this WS85 Tester and a USB UART adapter providing 3.3V
  11. assemble in reverse order. Optional: Add a ziptie as strain relief and some silicone to seal the cable outlet.