20dBm RS485 Wireless Modem Set 433MHz

Compact dual-module set: each unit measures 74 × 24 × 16 mm (excl. antenna), weighs ~45 g, and features rugged plastic + metal housing in blue finish. Powered by 4.5–5.5 V DC via RS485 terminal block (5V, GND, A+, B−). Operates across 433–458.5 MHz with 255 channel options and user-adjustable transmit power (−40 to +20 dBm, 10 discrete levels). Receiver sensitivity of −114 dBm ensures robust signal capture in noisy industrial or urban UK settings. Supports transparent serial transmission at baud rates 1200–19200 bps (default 9600); over-the-air data rate spans 10–100 kbps. Built-in MCU handles serial framing and ID-based routing. Works reliably from −25 °C to +75 °C — suitable for loft-mounted smart meters or outdoor gate controllers. Both modules are factory-matched and ready for immediate deployment: no pairing required. Supports flexible topologies — point-to-point (2 pcs), or multi-drop (≥3 pcs) with master/slave roles mirroring wired RS485 behaviour. Only one device transmits at a time, avoiding data collisions. Configuration via AT commands (e.g., AT+ENABLE=1) is possible exclusively during the first three minutes post-power-on — ensuring production systems remain locked to verified settings. Proven in UK smart home integrations (Wiser, Home Assistant), industrial telemetry (Modbus temperature/pressure sensors), security (wireless access control readers), and infrastructure (remote LED signage, water/gas metering), this set eliminates trenching costs while retaining full RS485 electrical and logical compatibility.