Introduction toSX1280
The SX1280 half-duplex radio frequency (RF) transceiver is a Semtech SX1200series ultra-low-power wireless transceiver with a working frequency of 2.4G.The chip contains multiple physical layers and multiple modulation methods suchas LORA, FLRC, and GFSK. The special modulation and processing method greatlyincreases the transmission distance of LORA and FLRC modulation, and GFSKmodulation is compatible with Bluetooth BLE protocol. Excellent low-powerperformance, on-chip DC-DC and Time-of-flight make this chip powerful for smarthomes, security systems, location tracking, wireless ranging, wearables, smartbracelets and health management Wait.

Introduction toE28-2G4M12S
E28-2G4M12S is a 2.4GHz RF transceiver module designed and manufactured byChengdu Ebyte, small-size patch type, maximum power 12.5dBm, the module comes withhigh-performance PCB on-board antenna, working in the 2.400~2.500GHz band, mostWith a long transmission distance of 2Km, it has extremely low powerconsumption in low power mode, excellent performance and stronganti-interference ability. E28-2G4M12S is a hardware module, there is noprogram at the factory, and the user needs to carry out secondary development.

E28-2G4M12S circuit design

The SX1280 chipuses a 52MHz passive crystal oscillator to provide the clock;
The RF circuit part is composed of a simple LC matching circuit and anelliptical filter, and an external 2.4 GHz antenna;
The connection of L4 is to make the high efficiency step-down to supply the RFpart of the chip.
The following is a list of BOMs:

Reference board design