Wireless module has been used in our daily life, but it is also quite extensive, according to small personal understanding to the general open area for transmitting and receiving module maximum transmission distance of about 800 meters, there is an obstacle in the case, then it is easy to shorten the distance, by its is for radio signal transmission process the reflection and refraction of the formation of some dead or is there some unstable region, different transceiver environment will appear different communication distance, for this we need to know.

Best can be installed vertically in the board edge for transmitting and receiving wireless module, then we need to pay attention to leave peripheral devices of 5mm and above, in order to avoid affected distribution parameters, module of transmission distance and modulation signal frequency and amplitude, transmitting voltage and the battery capacity, the transmitting antenna, the sensitivity of the receiver, transceiver environment.

At present, for transmitting and receiving wireless module mainly uses is the ASK modulation mode, to reduce power consumption, when the data signal to stop when the emission current is reduced to zero, the data signal and transmitting module input terminal can use resistance or is directly connected and not with the capacitive coupling, or launch a wireless module will not normally work, the data level should be the actual the working voltage is close to the data module, in order to obtain a higher modulation effect.