Wlx896b Schematic Exclusive Official

RX chain

TX chain

Frequency synthesis

Baseband / Digital

Power management

Test, calibration & debug

Near the FPC connector, pins 34-36 are routed to an unpopulated SOIC-8 (U5). The schematic calls it "Reserved for HDC1080" – but our tracing shows it is a standard I2C bus (SDA on Pin 34, SCL on Pin 35). You can solder any I2C sensor (BME280, MPU6050) here. The stock firmware will ignore it, but custom ESPHome or Tasmota builds will auto-detect it.

The WLX896B operates on a single 5V DC input (typically via a micro-USB or a 2-pin JST). The exclusive detail here is the cascading LDO topology. wlx896b schematic exclusive

[5V Input] ---> [Diode D1 (SS34)] ---> [U1 (AMS1117)] ---> 3.3V Rail
                                  |
                                  ----> [U2 (RT9193)] ---> 1.8V Rail