Dear all，
At present, the test distance of our product is about 20 meters. Under this distance, we can conduct stable communication and test 10 samples.
The attachment is the schematic diagram used in the design, PCB and PCBA, communication is between the temperature sensor and the gateway, the main chip of the temperature sensor is STM8L151, the main chip of the gateway is STM32F105, all antennas adopt spring antennas.
Circuit board board fr-4, temperature sensor board thickness 1.0mm, gateway 1.6mm.
At work, the temperature sensor communicates one-way communication to the gateway, the sensor only emits data, and the gateway only receives data. The transmission in the software is designed to be the highest output power, with a bandwidth of 101.6kb.
The expected distance is more than 50 meters, please help to see what problems there are and what methods can improve the radio frequency communication distance.
